Chemistry › Organic Chemistry

Synthesis and Properties of Aromatic Compounds

Works Count: 28444

Wikipedia

Description

This cluster of papers explores the concept of aromaticity in organic molecules and materials, including the study of Nucleus-Independent Chemical Shifts (NICS), helical polymers, nanographene chemistry, circularly polarized luminescence, diradicals, and electron delocalization. It covers a wide range of topics related to the structural, electronic, and optical properties of aromatic and conjugated systems.

Keywords

Aromaticity; Helical Polymers; Nanographene Chemistry; Circularly Polarized Luminescence; Macrocyclic Aromatics; Diradicals; Heteroaromatic Compounds; Electron Delocalization; Nucleus-Independent Chemical Shifts (NICS); Conjugated Systems

Self-Consistent Orbitals for Radicals

1954-03-01

John A. Pople , R. K. Nesbet

View PDF Chat

Handbook of conducting polymers

1986-01-01

Terje A. Skotheim , Ronald L. Elsenbaumer , John R. Reynolds

Volume 1: Conjugated Polymers: Theory, Synthesis, Properties, and Characterization PART 1: THEORY OF CONJUGATED POLYMERS On the Transport, Optical, and Self-Assembly Properties of -Conjugated Materials: A Combined Theoretical/Experimental Insight D. … Volume 1: Conjugated Polymers: Theory, Synthesis, Properties, and Characterization PART 1: THEORY OF CONJUGATED POLYMERS On the Transport, Optical, and Self-Assembly Properties of -Conjugated Materials: A Combined Theoretical/Experimental Insight D. Beljonne, J. Cornil, V. Coropceanu, D.A. da Silva Filho, V. Geskin, R. Lazzaroni, P. Leclere, and J.-L. Bredas Theoretical Studies of Electron-Lattice Dynamics in Organic Systems S. Stafstroem PART 2: SYNTHESIS AND CLASSES OF CONJUGATED POLYMERS Helical Polyacetylene Synthesized in Chiral Nematic Liquid Crystals K. Akagi Synthesis and Properties of Poly(arylene vinylene)s A.C. Grimsdale and A.B. Holmes Blue-Emitting Poly(para-Phenylene)-Type Polymers E.J.W. List and U. Scherf Poly(paraPhenyleneethynylene)s and Poly(aryleneethynylene)s: Materials with a Bright Future U.H.F. Bunz Polyaniline Nanofibers: Synthesis, Properties, and Applications J. Huang and R.B. Kaner Recent Advances in Polypyrrole S.H. Cho, K.T. Song, and J.Y. Lee Regioregular Polythiophenes M. Jeffries-El and R.D. McCullough Poly(3,4-Ethylenedioxythiophene)-Scientific Importance, Remarkable Properties, and Applications S. Kirchmeyer, K. Reuter, and J.C. Simpson Thienothiophenes: From Monomers to Polymers G.A. Sotzing, V. Seshadri, and F.J. Waller Low Bandgap Conducting Polymers S.C. Rasmussen and M. Pomerantz Advanced Functional Polythiophenes Based on Tailored Precursors P. Blanchard, P. Leriche, P. Frere, and J. Roncali Structure-Property Relationships and Applications of Conjugated Polyelectrolytes K.S. Schanze and X. Zhao PART 3: PROPERTIES AND CHARACTERIZATION OF CONJUGATED POLYMERS Insulator-Metal Transition and Metallic State in Conducting Polymers A.J. Epstein One-Dimensional Charge Transport in Conducting Polymer Nanofibers A.N. Aleshin and Y.W. Park Structure Studies of - and - Conjugated Polymers M.J. Winokur Electrochemistry of Conducting Polymers P. Audebert and F. Miomandre Internal Fields and Electrode Interfaces in Organic Semiconductor Devices: Noninvasive Investigations via Electroabsorption T.M. Brown and F. Cacialli Electrochromism of Conjugated Conducting Polymers A.L. Dyer and J.R. Reynolds Photoelectron Spectroscopy of Conjugated Polymers M.P. de Jong, G. Greczyniski, W. Osikowicz, R. Friedlein, X. Crispin, M. Fahlman, and W.R. Salaneck Ultrafast Exciton Dynamics and Laser Action in -ConjugatedSemiconductors Z. Valy Vardeny and O. Korovyanko Volume 2: Conjugated Polymers: Processing and Applications PART 1: PROCESSING OF CONJUGATED POLYMERS Conductive Polymers as Organic Nanometals B. Wessling Conducting Polymer Fiber Production and Applications I.D. Norris and B.R. Mattes Inkjet Printing and Patterning of PEDOT-PSS: Application to Optoelectronic Devices Y. Yoshioka and G.E. Jabbour Printing Organic Electronics on Flexible Substrates N.D. Robinson and M. Berggren PART 2: APPLICATIONS AND DEVICES BASED ON CONJUGATED POLYMERS Polymers for Use in Polymeric Light-Emitting Diodes: Structure-Property Relationships H. Christian-Pandya, S. Vaidyanathan, and M. Galvin Organic Electro-Optic Materials L.R. Dalton Conjugated Polymer Electronics-Engineering Materials and Devices N. Tessler, J. Veres, O. Globerman, N. Rappaport, Y. Preezant, Y. Roichman, O. Solomesch, S. Tal, E. Gershman, M. Adler, V. Zolotarev, V. Gorelik, and Y. Eichen Electrical Bistable Polymer Films and Their Applications in Memory Devices J. Ouyang, C.-W. Chu, R.J. Tseng, A. Prakash, and Y. Yang Electroactive Polymers for Batteries and Supercapacitors J.A. Irvin, D.J. Irvin, and J.D. Stenger-Smith Conjugated Polymer-Based Photovoltaic Devices A.J. Mozer and N.S. Sariciftci Biomedical Applications of Inherently Conducting Polymers (ICPs),P.C. Innis, S.E. Moulton, and G.G. Wallace Biosensors Based on Conducting Electroactive Polymers S. Brahim, A.M. Wilson, and A. Guiseppi-Elie Optical Biosensors Based on Conjugated Polymers K. Peter, R. Nilsson, and O. Inganas Conjugated Polymers for Microelectromechanical and Other Microdevices G.M. Spinks and E. Smela Corrosion Protection Using Conducting Polymers D.E. Tallman and G.P. Bierwagen Artificial Muscles T.F. Otero

About Supramolecular Assemblies of π-Conjugated Systems

2005-03-10

Freek J. M. Hoeben , Pascal Jonkheijm , E. W. Meijer +1 more

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAbout Supramolecular Assemblies of π-Conjugated SystemsFreek J. M. Hoeben, Pascal Jonkheijm, E. W. Meijer, and Albertus P. H. J. SchenningView Author Information Laboratory of Macromolecular and Organic … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAbout Supramolecular Assemblies of π-Conjugated SystemsFreek J. M. Hoeben, Pascal Jonkheijm, E. W. Meijer, and Albertus P. H. J. SchenningView Author Information Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands Cite this: Chem. Rev. 2005, 105, 4, 1491–1546Publication Date (Web):March 10, 2005Publication History Received24 June 2004Published online10 March 2005Published inissue 1 April 2005https://pubs.acs.org/doi/10.1021/cr030070zhttps://doi.org/10.1021/cr030070zresearch-articleACS PublicationsCopyright © 2005 American Chemical SocietyRequest reuse permissionsArticle Views33328Altmetric-Citations2856LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Oligomers,Polymers,Supramolecular chemistry,Supramolecular structures and assemblies Get e-Alerts

Synthesis of highly conducting films of derivatives of polyacetylene, (CH)x

1978-02-01

C. K. Chiang , Mark A. Druy , S. C. Gau +5 more

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of highly conducting films of derivatives of polyacetylene, (CH)xC. K. Chiang, M. A. Druy, S. C. Gau, A. J. Heeger, E. J. Louis, A. G. MacDiarmid, … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of highly conducting films of derivatives of polyacetylene, (CH)xC. K. Chiang, M. A. Druy, S. C. Gau, A. J. Heeger, E. J. Louis, A. G. MacDiarmid, Y. W. Park, and H. ShirakawaCite this: J. Am. Chem. Soc. 1978, 100, 3, 1013–1015Publication Date (Print):February 1, 1978Publication History Published online1 May 2002Published inissue 1 February 1978https://pubs.acs.org/doi/10.1021/ja00471a081https://doi.org/10.1021/ja00471a081research-articleACS PublicationsRequest reuse permissionsArticle Views3558Altmetric-Citations671LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

One hundred years of helicene chemistry. Part 2: stereoselective syntheses and chiral separations of carbohelicenes

2012-11-15

Marc Gingras , Guy Félix , Romain Peresutti

Carbohelicenes generally incorporate a helical, distorted, conjugated, polyaromatic system with ortho-fused benzenoid rings, which is a fundamental molecular characteristic of this class of compounds. They have been described as "molecules … Carbohelicenes generally incorporate a helical, distorted, conjugated, polyaromatic system with ortho-fused benzenoid rings, which is a fundamental molecular characteristic of this class of compounds. They have been described as "molecules in distress" due to their distortion. The generation of a chiral helicity in helicenes was observed because of a severe intramolecular steric strain. Helicity is a molecular necessity in the higher series of carbohelicenes, when at some point, a helical pitch occurs when a second coil is formed. The most interesting properties resulting from such molecular distortion are the very high chiroptical and circular dichroism values. For instance, the resolution of some helicene racemates by "hand picking" of a few homochiral single enantiomeric crystals allowed for a measurement of their optical rotation. Due to that intrinsic chirality spanned over a large polyaromatic template, preliminary results clearly established the efficiency of carbohelicenes to induce asymmetry and chirality in organic synthesis and in supramolecular chemistry. Additionally, they have some potential uses in several fields: materials science, nanoscience, chemical biology and supramolecular chemistry. It has encouraged many attempts to develop new asymmetric syntheses of carbohelicenes, as well as some chiral separations of enantiomers and diastereoisomers. This review is thus dedicated to carbohelicene chirality. It gathered a substantial collection of data, and a comprehensive review on the preparations of enantioenriched helicenes, either from an asymmetric synthesis or from a chiral separation. Utilizations of non-racemic helicenes and their applications will be treated in the following review (Part 3), and will not be the subject of this manuscript.

Dissected nucleus-independent chemical shift analysis of pi-aromaticity and antiaromaticity.

2001-08-09

Paul von Ragué Schleyer , Mariappan Manoharan , Zhixiang Wang +4 more

[structure: see text] Analysis of the basic pi-aromatic (benzene) and antiaromatic (cyclobutadiene) systems by dissected nucleus-independent chemical shifts (NICS) shows the contrasting diatropic and paratropic effects, but also reveals subtleties … [structure: see text] Analysis of the basic pi-aromatic (benzene) and antiaromatic (cyclobutadiene) systems by dissected nucleus-independent chemical shifts (NICS) shows the contrasting diatropic and paratropic effects, but also reveals subtleties and unexpected details.

Rethinking the term “pi-stacking”

2012-01-01

Chelsea R. Martinez , Brent L. Iverson

It has become common to reference "pi-stacking" forces or "pi–pi interactions" when describing the interactions between neighbouring aromatic rings. Here, we review experimental and theoretical literature across several fields and … It has become common to reference "pi-stacking" forces or "pi–pi interactions" when describing the interactions between neighbouring aromatic rings. Here, we review experimental and theoretical literature across several fields and conclude that the terms "pi-stacking" and "pi–pi interactions" do not accurately describe the forces that drive association between aromatic molecules of the types most commonly studied in chemistry or biology laboratories. We therefore propose that these terms are misleading and should no longer be used. Even without these terms, electrostatic considerations relating to polarized pi systems, as described by Hunter and Sanders, have provided a good qualitative starting place for predicting and understanding the interactions between aromatics for almost two decades. More recent work, however, is revealing that direct electrostatic interactions between polarized atoms of substituents as well as solvation/desolvation effects in strongly interacting solvents must also be considered and even dominate in many circumstances.

View PDF Chat

Benzynes, dehydroconjugated molecules, and the interaction of orbitals separated by a number of intervening sigma bonds

1968-03-01

Roald Hoffmann , Akira Imamura , Warren J. Hehre

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBenzynes, dehydroconjugated molecules, and the interaction of orbitals separated by a number of intervening sigma bondsRoald Hoffmann, Akira Imamura, and Warren J. HehreCite this: J. Am. Chem. … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBenzynes, dehydroconjugated molecules, and the interaction of orbitals separated by a number of intervening sigma bondsRoald Hoffmann, Akira Imamura, and Warren J. HehreCite this: J. Am. Chem. Soc. 1968, 90, 6, 1499–1509Publication Date (Print):March 1, 1968Publication History Published online1 May 2002Published inissue 1 March 1968https://pubs.acs.org/doi/10.1021/ja01008a018https://doi.org/10.1021/ja01008a018research-articleACS PublicationsRequest reuse permissionsArticle Views1801Altmetric-Citations622LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

One hundred years of helicene chemistry. Part 3: applications and properties of carbohelicenes

2012-11-15

Marc Gingras

Carbohelicenes are a class of fascinating chiral helical molecules which have a rich history in chemistry. Over a period of almost 100 years, chemists have developed many methods to prepare … Carbohelicenes are a class of fascinating chiral helical molecules which have a rich history in chemistry. Over a period of almost 100 years, chemists have developed many methods to prepare them in a racemic or in a non-racemic form. They also possess a series of interesting chiral, physical, electronic and optical properties. However, their utilization in chemistry or chemistry-related fields has rarely appeared in a detailed and comprehensive review. It is the purpose of this review to collect fundamental applications and functions involving carbohelicenes in various disciplines such as in materials science, in nanoscience, in biological chemistry and in supramolecular chemistry. From the numerous synthetic methodologies reported up to now, carbohelicenes and their derivatives can be tailor-made for a better involvement in several subfields. Among those domains are: nanosciences, chemosensing, liquid crystals, molecular switches, polymers, foldamers, supramolecular materials, molecular recognition, conductive and opto-electronic materials, nonlinear optics, chirality studies and asymmetric synthesis. Helicene chemistry is now at a developmental stage, where sufficient application data are now collected and are extremely useful. They provide many more ideas for setting up the basis for future innovative applications.

A Road Map to Stable, Soluble, Easily Crystallized Pentacene Derivatives

2001-12-15

John E. Anthony , David L. Eaton , Sean Parkin

[structure: see text] A series of 6,13-disubstituted pentacenes, in which the substituents are functionalized ethyne units, were synthesized and analyzed by X-ray crystallography. The resulting pentacene derivatives were highly soluble … [structure: see text] A series of 6,13-disubstituted pentacenes, in which the substituents are functionalized ethyne units, were synthesized and analyzed by X-ray crystallography. The resulting pentacene derivatives were highly soluble and oxidatively stable and exhibited a significant amount of pi-stacking in the crystal.

Big Is Beautiful−“Aromaticity” Revisited from the Viewpoint of Macromolecular and Supramolecular Benzene Chemistry

2001-04-20

Mark D. Watson , Andreas Fechtenkötter , Kläus Müllen

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBig Is Beautiful−"Aromaticity" Revisited from the Viewpoint of Macromolecular and Supramolecular Benzene ChemistryMark D. Watson, Andreas Fechtenkötter, and Klaus MüllenView Author Information Max-Planck-Institut für Polymerforschung, Ackermannweg 10, … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBig Is Beautiful−"Aromaticity" Revisited from the Viewpoint of Macromolecular and Supramolecular Benzene ChemistryMark D. Watson, Andreas Fechtenkötter, and Klaus MüllenView Author Information Max-Planck-Institut für Polymerforschung, Ackermannweg 10, D-55128 Mainz, Germany Cite this: Chem. Rev. 2001, 101, 5, 1267–1300Publication Date (Web):April 20, 2001Publication History Received22 September 2000Published online20 April 2001Published inissue 1 May 2001https://pubs.acs.org/doi/10.1021/cr990322phttps://doi.org/10.1021/cr990322presearch-articleACS PublicationsCopyright © 2001 American Chemical SocietyRequest reuse permissionsArticle Views12722Altmetric-Citations1264LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Chemical structure,Hydrocarbons,Molecules,Polymers Get e-Alerts

Circularly polarized light detection by a chiral organic semiconductor transistor

2013-07-19

Ying Yang , Rosenildo Corrêa da Costa , Matthew J. Fuchter +1 more

The alternation of bond lengths in long conjugated chain molecules

1959-05-26

Hugh Christopher Longuet-Higgins , L. Salem

Ooshika (1957) has recently found, using the self-consistent molecular orbital theory, that a cyclicpolyene C 2n H 2n exhibits marked bond alternation if n is very large. Here we show … Ooshika (1957) has recently found, using the self-consistent molecular orbital theory, that a cyclicpolyene C 2n H 2n exhibits marked bond alternation if n is very large. Here we show that, provided bond compression is taken into account, this result follows inevitably from even the simple l.c.a.o. theory, and is independent of the analytic form of either /?( r ), the resonance integral, or f ( r ), the cr bond energy. An investigation of the linear polyenes C 2n H 2n+2 and C 2n+1 H 2n+3 leads to the same conclusions, which contradict those of Lennard-Jones (1937) and Coulson (1938) but agree with those of Ooshika (1957) and Labhart (1957). A simple calculation, based on an exponential form for leads to a value of about 0.04 A for the difference in length between adjacent bonds in the infinite chain.

Geodesic Polyarenes by Flash Vacuum Pyrolysis

2006-11-09

Vikki M. Tsefrikas , Lawrence T. Scott

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGeodesic Polyarenes by Flash Vacuum PyrolysisVikki M. Tsefrikas and Lawrence T. ScottView Author Information Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467 Cite this: Chem. Rev. … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGeodesic Polyarenes by Flash Vacuum PyrolysisVikki M. Tsefrikas and Lawrence T. ScottView Author Information Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467 Cite this: Chem. Rev. 2006, 106, 12, 4868–4884Publication Date (Web):November 9, 2006Publication History Received8 May 2006Published online9 November 2006Published inissue 1 December 2006https://pubs.acs.org/doi/10.1021/cr050553yhttps://doi.org/10.1021/cr050553yresearch-articleACS PublicationsCopyright © 2006 American Chemical SocietyRequest reuse permissionsArticle Views5397Altmetric-Citations666LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Carbon nanomaterials,Cyclization,Hydrocarbons,Hydrogen,Precursors Get e-Alerts

To What Extent Can Aromaticity Be Defined Uniquely?

2002-01-30

Michał K. Cyrański , Tadeusz M. Krygowski , Alan R. Katritzky +1 more

Statistical analyses of quantitative definitions of aromaticity, ASE (aromatic stabilization energies), RE (resonance energies), Lambda (magnetic susceptibility exaltation), NICS, HOMA, I5, and A(J), evaluated for a set of 75 five-membered … Statistical analyses of quantitative definitions of aromaticity, ASE (aromatic stabilization energies), RE (resonance energies), Lambda (magnetic susceptibility exaltation), NICS, HOMA, I5, and A(J), evaluated for a set of 75 five-membered pi-electron systems: aza and phospha derivatives of furan, thiophene, pyrrole, and phosphole (aromatic systems), and a set of 30 ring-monosubstituted compounds (aromatic, nonaromatic, and antiaromatic systems) revealed statistically significant correlations among the various aromaticity criteria, provided the whole set of compounds is involved. Hence, broadly considered, the various manifestations of aromaticity are related and aromaticity can be regarded statistically as a one-dimensional phenomenon. In contrast, when comparisons are restricted to some regions or groups of compounds, e.g., aromatic compounds with ASE > 5 kcal/mol or polyhetero-five-membered rings, the quality of the correlations can deteriorate or even vanish. In practical applications, energetic, geometric, and magnetic desriptors of aromaticity do not speak with the same voice. Thus, in this sense, the phenomenon of aromaticity is regarded as being statistically multidimensional.

An Evaluation of the Aromaticity of Inorganic Rings: Refined Evidence from Magnetic Properties

1997-12-01

Paul von Ragué Schleyer , Haijun Jiao , Nicolaas J. R. van Eikema Hommes +2 more

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTAn Evaluation of the Aromaticity of Inorganic Rings: Refined Evidence from Magnetic PropertiesPaul von Ragué Schleyer, Haijun Jiao, Nicolaas J. R. van Eikema Hommes, Vladimir G. Malkin, … ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTAn Evaluation of the Aromaticity of Inorganic Rings: Refined Evidence from Magnetic PropertiesPaul von Ragué Schleyer, Haijun Jiao, Nicolaas J. R. van Eikema Hommes, Vladimir G. Malkin, and Olga L. MalkinaView Author Information Computer Chemistry Center, Institut für Organische Chemie, Universität Erlangen-Nürnberg Henkestrasse 42, D-91054 Erlangen, Germany Institut of Inorganic Chemistry Slovak Academy of Sciences Dubravska Cesta, SK.84236, Bratislava, Slovakia Cite this: J. Am. Chem. Soc. 1997, 119, 51, 12669–12670Publication Date (Web):December 24, 1997Publication History Received11 June 1997Revised8 October 1997Published online24 December 1997Published inissue 1 December 1997https://pubs.acs.org/doi/10.1021/ja9719135https://doi.org/10.1021/ja9719135rapid-communicationACS PublicationsCopyright © 1997 American Chemical SocietyRequest reuse permissionsArticle Views3056Altmetric-Citations909LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Aromaticity,Hydrocarbons,Magnetic properties,Molecules Get e-Alerts

Aromaticity as a Cornerstone of Heterocyclic Chemistry

2004-04-17

Alexandrù T. Balaban , Daniela C. Oniciu , Alan R. Katritzky

ADVERTISEMENT RETURN TO ISSUEPREVArticleAromaticity as a Cornerstone of Heterocyclic ChemistryAlexandru T. Balaban, Daniela C. Oniciu, and Alan R. KatritzkyView Author Information Texas A&M University at Galveston, 5007 Avenue U, Galveston, … ADVERTISEMENT RETURN TO ISSUEPREVArticleAromaticity as a Cornerstone of Heterocyclic ChemistryAlexandru T. Balaban, Daniela C. Oniciu, and Alan R. KatritzkyView Author Information Texas A&M University at Galveston, 5007 Avenue U, Galveston, Texas 77551 Esperion Therapeutics (a Division of Pfizer Global Research and Development), 3621 South State Street, Ann Arbor, Michigan 48108 Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200 Cite this: Chem. Rev. 2004, 104, 5, 2777–2812Publication Date (Web):April 17, 2004Publication History Received9 October 2003Published online17 April 2004Published inissue 1 May 2004https://pubs.acs.org/doi/10.1021/cr0306790https://doi.org/10.1021/cr0306790research-articleACS PublicationsCopyright © 2004 American Chemical SocietyRequest reuse permissionsArticle Views9861Altmetric-Citations628LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Aromaticity,Energy,Heterocyclic compounds,Reaction products Get e-Alerts

Théorie quantique des courants interatomiques dans les combinaisons aromatiques

1937-01-01

F. London

Nous exposons ici une theorie quantique de l'anisotropie diamagnetique anomale, observee dans les combinaisons aromatiques. Elle s'explique par un mecanisme de courants interatomiques particulier a ces combinaisons Nous montrons pourquoi … Nous exposons ici une theorie quantique de l'anisotropie diamagnetique anomale, observee dans les combinaisons aromatiques. Elle s'explique par un mecanisme de courants interatomiques particulier a ces combinaisons Nous montrons pourquoi ces courants ne peuvent se manifester ni a l'interieur des combinaisons saturees, meme cycliques, ni entre des arrangements moleculaires satures. Nous traitons comme exemples le benzene, le naphtalene, l'anthracene, le diphenyle, le pyrene et le phenanthrene.

View PDF Chat

One hundred years of helicene chemistry. Part 1: non-stereoselective syntheses of carbohelicenes

2012-11-15

Marc Gingras

Carbohelicenes belong to a class of fascinating, chiral, and helicoidal molecules, which have a rich history in chemistry since the very beginning of the 20th century. A renewed interest in … Carbohelicenes belong to a class of fascinating, chiral, and helicoidal molecules, which have a rich history in chemistry since the very beginning of the 20th century. A renewed interest in polyaromatic chemistry and new synthetic challenges toward the search for innovative physical, biological, chemical and opto-electronic properties have brought high motivation in this field of studies. Theoretical insights gained from polyaromatic, chiral, conjugated and distorted π-systems are also responsible for this development. Several synthetic avenues were originally reported for making lower helicenes, but for many years, photochemical synthesis has remained a major method for producing small amount of helicenes. High-dilution conditions is still a limiting factor in their synthesis. The fulgurous impact of organometallic chemistry, novel synthetic methods, and recent catalytic systems has promoted the development of helicene chemistry, toward a library of tailor-made and highly functionalized helicene molecules. Helicene chemistry is being considered as an expanding and modern field, leading to several applications in supramolecular chemistry, in nanosciences, in chemical-biology, in polymers and materials science. This first part of a series of three reviews on carbohelicenes will be devoted to a comprehensive report on non-stereoselective reactions and methods for producing helicenes, along with their functionalization.

Aromaticity and Ring Currents

2001-05-01

J.A.N.F. Gomes , R. B. Mallion

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAromaticity and Ring CurrentsJ. A. N. F. Gomes and R. B. MallionView Author Information CEQUP/Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAromaticity and Ring CurrentsJ. A. N. F. Gomes and R. B. MallionView Author Information CEQUP/Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 697, 4150−049 Porto, Portugal The King's School, Canterbury, Kent, CT1 2ES, England, U.K. Cite this: Chem. Rev. 2001, 101, 5, 1349–1384Publication Date (Web):May 9, 2001Publication History Received1 August 2000Published online9 May 2001Published inissue 1 May 2001https://pubs.acs.org/doi/10.1021/cr990323hhttps://doi.org/10.1021/cr990323hresearch-articleACS PublicationsCopyright © 2001 American Chemical SocietyRequest reuse permissionsArticle Views6701Altmetric-Citations531LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Aromaticity,Hydrocarbons,Magnetic properties,Molecules Get e-Alerts

Nucleus-Independent Chemical Shifts (NICS): Distance Dependence and Revised Criteria for Aromaticity and Antiaromaticity

2005-12-30

Amnon Stanger

Nucleus-independent chemical shifts (NICS) have been used extensively for the identification of aromaticity properties of molecules, ions, intermediates, and transition states since their introduction in 1996 by Schleyer et al. … Nucleus-independent chemical shifts (NICS) have been used extensively for the identification of aromaticity properties of molecules, ions, intermediates, and transition states since their introduction in 1996 by Schleyer et al. Initially, probes (bq's) were placed at the centers of systems (NICS(0)) and later, 1Å above the molecular planes (NICS(1)). However, contradicting assignments of aromaticity by NICS and other methods were found for some systems. In this article, an alternative NICS-based method is introduced. The method is based on scanning NICS values over a distance and separating them into in-plane and out-of plane contributions. The shapes of the plots of the chemical shifts and their components as a function of the distance of the NICS probe (bq) from the molecular plane give a clear indication of diamagnetic and paramagnetic ring currents. This method is applied to several (4n + 2)- and 4n π-electron systems (molecules and ions) in the singlet and triplet electronic states, including some of the problematic systems mentioned above. It is also shown that relative aromaticities of rings in polycyclic systems (local aromaticities) cannot be estimated by comparing NICS or NICS-scan values.

Nucleus-Independent Chemical Shifts (NICS) as an Aromaticity Criterion

2005-09-29

Zhongfang Chen , Chaitanya S. Wannere , Clémence Corminbœuf +2 more

A comprehensive review is presented on nucleus-independent chem. shift as a criterion for aromaticity. [on SciFinder (R)] A comprehensive review is presented on nucleus-independent chem. shift as a criterion for aromaticity. [on SciFinder (R)]

Delocalization of Electrons in Molecules

2001-03-14

Rainer Herges , Daniel Geuenich

We report a general method for the investigation and quantification of delocalization in molecules. The method is based on the anisotropy of the current-induced density (ACID). Compared to the current … We report a general method for the investigation and quantification of delocalization in molecules. The method is based on the anisotropy of the current-induced density (ACID). Compared to the current density, which has been frequently used to investigate delocalization, the ACID approach has several advantages: it is a scalar field which is invariant with respect to the relative orientation of the magnetic field and the molecule, it is not a simple function of the overall electron density, it has the same symmetry as the wave function, and it can be plotted as an isosurface. Several selected examples demonstrate the predictive power and the general applicability of this method.

Anisotropy of the Induced Current Density (ACID), a General Method To Quantify and Visualize Electronic Delocalization

2005-09-15

Daniel Geuenich , Kirsten Heß , Felix Köhler +1 more

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAnisotropy of the Induced Current Density (ACID), a General Method To Quantify and Visualize Electronic DelocalizationDaniel Geuenich, Kirsten Hess, Felix Köhler, and Rainer HergesView Author Information Institut … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAnisotropy of the Induced Current Density (ACID), a General Method To Quantify and Visualize Electronic DelocalizationDaniel Geuenich, Kirsten Hess, Felix Köhler, and Rainer HergesView Author Information Institut für Organische Chemie, Universität Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany Cite this: Chem. Rev. 2005, 105, 10, 3758–3772Publication Date (Web):September 15, 2005Publication History Received15 December 2004Published online15 September 2005Published inissue 1 October 2005https://pubs.acs.org/doi/10.1021/cr0300901https://doi.org/10.1021/cr0300901research-articleACS PublicationsCopyright © 2005 American Chemical SocietyRequest reuse permissionsArticle Views13795Altmetric-Citations1145LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Delocalization,Electrical properties,Hydrocarbons,Molecular properties Get e-Alerts

Nucleus-Independent Chemical Shifts: A Simple and Efficient Aromaticity Probe

1996-01-01

Paul von Ragué Schleyer , Christoph Maerker , Alk Dransfeld +2 more

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTNucleus-Independent Chemical Shifts: A Simple and Efficient Aromaticity ProbePaul von Ragué Schleyer*, Christoph Maerker, Alk Dransfeld, Haijun Jiao, and Nicolaas J. R. van Eikema HommesView Author Information … ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTNucleus-Independent Chemical Shifts: A Simple and Efficient Aromaticity ProbePaul von Ragué Schleyer*, Christoph Maerker, Alk Dransfeld, Haijun Jiao, and Nicolaas J. R. van Eikema HommesView Author Information Computer Chemistry Center, Institut für Organische Chemie, Universität Erlangen-Nürnberg Henkestrasse 42, D-91054 Erlangen, Germany In papers with more than one author, the asterisk indicates the name of the author to whom inquiries about the paper should be addressed.Cite this: J. Am. Chem. Soc. 1996, 118, 26, 6317–6318Publication Date (Web):July 3, 1996Publication History Received22 February 1996Revised29 April 1996Published online3 July 1996Published inissue 1 January 1996https://pubs.acs.org/doi/10.1021/ja960582dhttps://doi.org/10.1021/ja960582drapid-communicationACS PublicationsCopyright © 1996 American Chemical SocietyRequest reuse permissionsArticle Views22313Altmetric-Citations5277LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Aromaticity,Carbon nanomaterials,Hydrocarbons,Nanospheres Get e-Alerts

Synthesis, Characterization, and Theory of [9]-, [12]-, and [18]Cycloparaphenylene: Carbon Nanohoop Structures

2008-12-04

Ramesh Jasti , Joydeep Bhattacharjee , Jeffrey B. Neaton +1 more

The first synthesis and characterization of [9]-, [12]-, and [18]cycloparaphenylene was demonstrated utilizing a novel aromatization reaction. We refer to these fascinating structures as "carbon nanohoops" due to their structural … The first synthesis and characterization of [9]-, [12]-, and [18]cycloparaphenylene was demonstrated utilizing a novel aromatization reaction. We refer to these fascinating structures as "carbon nanohoops" due to their structural similarity to carbon nanotubes. Additionally, we have utilized computational methods to understand the unique properties of these fully conjugated macrocycles.

View PDF Chat

Aromaticity of Polycyclic Conjugated Hydrocarbons

2003-07-29

Milan Randić

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAromaticity of Polycyclic Conjugated HydrocarbonsMilan RandićView Author Information National Institute of Chemistry, Ljubljana, Slovenia Cite this: Chem. Rev. 2003, 103, 9, 3449–3606Publication Date (Web):July 29, 2003Publication History … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAromaticity of Polycyclic Conjugated HydrocarbonsMilan RandićView Author Information National Institute of Chemistry, Ljubljana, Slovenia Cite this: Chem. Rev. 2003, 103, 9, 3449–3606Publication Date (Web):July 29, 2003Publication History Received13 December 2001Published online29 July 2003Published inissue 1 September 2003https://pubs.acs.org/doi/10.1021/cr9903656https://doi.org/10.1021/cr9903656research-articleACS PublicationsCopyright © 2003 American Chemical SocietyRequest reuse permissionsArticle Views6961Altmetric-Citations644LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Chemical structure,Circuits,Hydrocarbons,Molecular structure Get e-Alerts

Field and resonance components of substituent effects

1968-07-01

C. Gardner Swain , Elmer C. Lupton

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTField and resonance components of substituent effectsC. Gardner Swain and Elmer C. LuptonCite this: J. Am. Chem. Soc. 1968, 90, 16, 4328–4337Publication Date (Print):July 1, 1968Publication History … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTField and resonance components of substituent effectsC. Gardner Swain and Elmer C. LuptonCite this: J. Am. Chem. Soc. 1968, 90, 16, 4328–4337Publication Date (Print):July 1, 1968Publication History Published online1 May 2002Published inissue 1 July 1968https://pubs.acs.org/doi/10.1021/ja01018a024https://doi.org/10.1021/ja01018a024research-articleACS PublicationsRequest reuse permissionsArticle Views1816Altmetric-Citations806LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Which NICS Aromaticity Index for Planar π Rings Is Best?

2006-02-02

Hossain Fallah‐Bagher‐Shaidaei , Chaitanya S. Wannere , Clémence Corminbœuf +2 more

Five increasingly sophisticated aromaticity indexes, based on nucleus-independent chemical shifts (NICS), were evaluated against a uniform set of aromatic stabilization energies (ASE) for 75 mono- and polyheterocyclic five-membered rings. While … Five increasingly sophisticated aromaticity indexes, based on nucleus-independent chemical shifts (NICS), were evaluated against a uniform set of aromatic stabilization energies (ASE) for 75 mono- and polyheterocyclic five-membered rings. While acceptable statistical correlations were given by all of the NICS methods, the most fundamentally grounded index, NICS(0)pizz (based on the pi contribution to the out-of-plane zz tensor component), performed best statistically (cc=0.980) and in practice. The easily computable NICS(1)zz index is a useful alternative (cc=0.968).

Conceptual and Computational DFT in the Study of Aromaticity

2001-04-24

Frank De Proft , Paul Geerlings

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConceptual and Computational DFT in the Study of AromaticityFrank De Proft and Paul GeerlingsView Author Information Eenheid Algemene Chemie, Vrije Universiteit Brussel, Faculteit Wetenschappen, Pleinlaan 2, 1050 … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConceptual and Computational DFT in the Study of AromaticityFrank De Proft and Paul GeerlingsView Author Information Eenheid Algemene Chemie, Vrije Universiteit Brussel, Faculteit Wetenschappen, Pleinlaan 2, 1050 Brussels, Belgium Cite this: Chem. Rev. 2001, 101, 5, 1451–1464Publication Date (Web):April 24, 2001Publication History Received22 August 2000Published online24 April 2001Published inissue 1 May 2001https://pubs.acs.org/doi/10.1021/cr9903205https://doi.org/10.1021/cr9903205research-articleACS PublicationsCopyright © 2001 American Chemical SocietyRequest reuse permissionsArticle Views5461Altmetric-Citations551LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Aromaticity,Density functional theory,Hardness,Molecules Get e-Alerts

Observation of All-Metal Aromatic Molecules

2001-02-02

Xi Li , Aleksey E. Kuznetsov , Haifeng Zhang +2 more

Aromaticity is a concept invented to account for the unusual stability of an important class of organic molecules: the aromatic compounds. Here we report experimental and theoretical evidence of aromaticity … Aromaticity is a concept invented to account for the unusual stability of an important class of organic molecules: the aromatic compounds. Here we report experimental and theoretical evidence of aromaticity in all-metal systems. A series of bimetallic clusters with chemical composition MAl 4 – (M = Li, Na, or Cu), was created and studied with photoelectron spectroscopy and ab initio calculations. All the MAl 4 – species possess a pyramidal structure containing an M + cation interacting with a square Al 4 2– unit. Ab initio studies indicate that Al 4 2– exhibits characteristics of aromaticity with two delocalized π electrons (thus following the 4 n + 2 electron counting rule) and a square planar structure and maintains its structural and electronic features in all the MAl 4 – complexes. These findings expand the aromaticity concept into the arena of all-metal species.

Structural Aspects of Aromaticity

2001-03-08

Tadeusz M. Krygowski , Michał K. Cyrański

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructural Aspects of AromaticityTadeusz Marek Krygowski and Michał Ksawery CyrańskiView Author Information Department of Chemistry, University of Warsaw, Pasteura 1, 02 093 Warsaw, Poland Cite this: Chem. … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructural Aspects of AromaticityTadeusz Marek Krygowski and Michał Ksawery CyrańskiView Author Information Department of Chemistry, University of Warsaw, Pasteura 1, 02 093 Warsaw, Poland Cite this: Chem. Rev. 2001, 101, 5, 1385–1420Publication Date (Web):March 8, 2001Publication History Received3 August 2000Published online8 March 2001Published inissue 1 May 2001https://pubs.acs.org/doi/10.1021/cr990326uhttps://doi.org/10.1021/cr990326uresearch-articleACS PublicationsCopyright © 2001 American Chemical SocietyRequest reuse permissionsArticle Views8903Altmetric-Citations1151LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Aromaticity,Hydrocarbons,Mathematical methods,Molecules Get e-Alerts

Circularly polarized luminescence spectroscopy

1986-02-01

James P. Riehl , F. S. Richardson

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCircularly polarized luminescence spectroscopyJames P. Riehl and Frederick S. RichardsonCite this: Chem. Rev. 1986, 86, 1, 1–16Publication Date (Print):February 1, 1986Publication History Published online1 May 2002Published inissue … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCircularly polarized luminescence spectroscopyJames P. Riehl and Frederick S. RichardsonCite this: Chem. Rev. 1986, 86, 1, 1–16Publication Date (Print):February 1, 1986Publication History Published online1 May 2002Published inissue 1 February 1986https://pubs.acs.org/doi/10.1021/cr00071a001https://doi.org/10.1021/cr00071a001research-articleACS PublicationsRequest reuse permissionsArticle Views7362Altmetric-Citations711LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Circularly Polarized Luminescence from Simple Organic Molecules

2015-07-01

Esther M. Sánchez‐Carnerero , Antonia R. Agarrabeitia , Florencio Moreno +4 more

Abstract This article aims to show the identity of “circularly polarized luminescent active simple organic molecules” as a new concept in organic chemistry due to the potential interest of these … Abstract This article aims to show the identity of “circularly polarized luminescent active simple organic molecules” as a new concept in organic chemistry due to the potential interest of these molecules, as availed by the exponentially growing number of research articles related to them. In particular, it describes and highlights the interest and difficulty in developing chiral simple (small and non‐aggregated) organic molecules able to emit left‐ or right‐circularly polarized light efficiently, the efforts realized up to now to reach this challenging objective, and the most significant milestones achieved to date. General guidelines for the preparation of these interesting molecules are also presented.

View PDF Chat

What is aromaticity?

1996-01-01

P. Rague von Schleyer , Haijun Jiao

Abstract Abstract

View PDF Chat

Ball-, Bowl-, and Belt-Shaped Conjugated Systems and Their Complexing Abilities: Exploration of the Concave−Convex π−π Interaction

2006-09-29

Takeshi Kawase , Hiroyuki Kurata

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBall-, Bowl-, and Belt-Shaped Conjugated Systems and Their Complexing Abilities: Exploration of the Concave−Convex π−π InteractionTakeshi Kawase and Hiroyuki KurataView Author Information Department of Chemistry, Graduate School … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBall-, Bowl-, and Belt-Shaped Conjugated Systems and Their Complexing Abilities: Exploration of the Concave−Convex π−π InteractionTakeshi Kawase and Hiroyuki KurataView Author Information Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan Cite this: Chem. Rev. 2006, 106, 12, 5250–5273Publication Date (Web):September 29, 2006Publication History Received22 March 2006Published online29 September 2006Published inissue 1 December 2006https://pubs.acs.org/doi/10.1021/cr0509657https://doi.org/10.1021/cr0509657research-articleACS PublicationsCopyright © 2006 American Chemical SocietyRequest reuse permissionsArticle Views7968Altmetric-Citations538LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Carbon nanomaterials,Hydrocarbons,Molecules,Nanospheres Get e-Alerts

Energetic Aspects of Cyclic Pi-Electron Delocalization: Evaluation of the Methods of Estimating Aromatic Stabilization Energies

2005-09-03

Michał K. Cyrański

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEnergetic Aspects of Cyclic Pi-Electron Delocalization: Evaluation of the Methods of Estimating Aromatic Stabilization EnergiesMichał Ksawery CyrańskiView Author Information Department of Chemistry, University of Warsaw, Pasteura 1, … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEnergetic Aspects of Cyclic Pi-Electron Delocalization: Evaluation of the Methods of Estimating Aromatic Stabilization EnergiesMichał Ksawery CyrańskiView Author Information Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland Cite this: Chem. Rev. 2005, 105, 10, 3773–3811Publication Date (Web):September 3, 2005Publication History Received29 November 2004Published online3 September 2005Published inissue 1 October 2005https://pubs.acs.org/doi/10.1021/cr0300845https://doi.org/10.1021/cr0300845research-articleACS PublicationsCopyright © 2005 American Chemical SocietyRequest reuse permissionsArticle Views5186Altmetric-Citations539LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Aromaticity,Energy,Hydrocarbons,Stabilization Get e-Alerts

Pro-aromatic and anti-aromatic π-conjugated molecules: an irresistible wish to be diradicals

2015-01-01

Zebing Zeng , Xueliang Shi , Chunyan Chi +3 more

Aromaticity is an important concept to understand the stability and physical properties of π-conjugated molecules. Recent studies on pro-aromatic and anti-aromatic molecules revealed their irresistible tendency to become diradicals in … Aromaticity is an important concept to understand the stability and physical properties of π-conjugated molecules. Recent studies on pro-aromatic and anti-aromatic molecules revealed their irresistible tendency to become diradicals in the ground state. Diradical character thus becomes another very important concept and it is fundamentally correlated to the physical (optical, electronic and magnetic) properties and chemical reactivity of most of the organic optoelectronic materials. Molecules with distinctive diradical character show unique properties which are very different from those of traditional closed-shell π-conjugated systems, and thus they have many potential applications in organic electronics, spintronics, non-linear optics and energy storage. This critical review first introduces the fundamental electronic structure of Kekulé diradicals within the concepts of anti-aromaticity and pro-aromaticity in the context of Hückel aromaticity and diradical character. Then recent research studies on various stable/persistent diradicaloids based on pro-aromatic and anti-aromatic compounds are summarized and discussed with regard to their synthetic chemistry, physical properties, structure-property relationships and potential material applications. A summary and personal perspective is given at the end.

Helicenes: Synthesis and Applications

2011-10-24

Yun Shen , Chuan‐Feng Chen

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTHelicenes: Synthesis and ApplicationsYun Shen†‡ and Chuan-Feng Chen†*View Author Information† Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, … ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTHelicenes: Synthesis and ApplicationsYun Shen†‡ and Chuan-Feng Chen†*View Author Information† Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China‡ Graduate School, Chinese Academy of Sciences, Beijing 100049, China*E-mail: [email protected]Cite this: Chem. Rev. 2012, 112, 3, 1463–1535Publication Date (Web):October 24, 2011Publication History Received25 March 2011Published online24 October 2011Published inissue 14 March 2012https://pubs.acs.org/doi/10.1021/cr200087rhttps://doi.org/10.1021/cr200087rreview-articleACS PublicationsCopyright © 2011 American Chemical SocietyRequest reuse permissionsArticle Views34216Altmetric-Citations1179LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Chemical structure,Cyclization,Precursors,Substituents Get e-Alerts

Circularly Polarized Luminescence in Chiral Molecules and Supramolecular Assemblies

2015-08-13

Jatish Kumar , Takuya Nakashima , Tsuyoshi Kawai

Circularly polarized luminescence, or CPL, is a luminescence phenomenon that provides the differential emission intensity of right and left circularly polarized light, thereby providing information on the excited state properties … Circularly polarized luminescence, or CPL, is a luminescence phenomenon that provides the differential emission intensity of right and left circularly polarized light, thereby providing information on the excited state properties of the chiral molecular systems. In recent years, there has been a growing interest toward the development of organic chromophores capable of circularly polarized emission due to their potential applications in sensors, asymmetric synthesis as well as display and optical storage devices. The major drawback with organic molecules is the low dissymmetric factors exhibited by these systems. One of the recent strategies adopted for the improvement in luminescence dissymmetry of organic systems is through the controlled self-assembly of chromophores. In this Perspective, we highlight the recent experimental and theoretical developments in the field of chiral organic chromophoric systems and their self-assembly, that has produced promising results toward the enhancement of glum values in CPL.

Supramolecular Helical Systems: Helical Assemblies of Small Molecules, Foldamers, and Polymers with Chiral Amplification and Their Functions

2016-10-18

Eiji Yashima , Naoki Ousaka , Daisuke Taura +3 more

In this review, we describe the recent advances in supramolecular helical assemblies formed from chiral and achiral small molecules, oligomers (foldamers), and helical and nonhelical polymers from the viewpoints of … In this review, we describe the recent advances in supramolecular helical assemblies formed from chiral and achiral small molecules, oligomers (foldamers), and helical and nonhelical polymers from the viewpoints of their formations with unique chiral phenomena, such as amplification of chirality during the dynamic helically assembled processes, properties, and specific functionalities, some of which have not been observed in or achieved by biological systems. In addition, a brief historical overview of the helical assemblies of small molecules and remarkable progress in the synthesis of single-stranded and multistranded helical foldamers and polymers, their properties, structures, and functions, mainly since 2009, will also be described.

Circularly Polarized Luminescence and Circular Dichroisms in Small Organic Molecules: Correlation between Excitation and Emission Dissymmetry Factors

2018-02-10

Hiroki Tanaka , Yoshihisa Inoue , Tadashi Mori

Abstract Prompted by the recent rapid growth of interest in circularly polarized luminescence (CPL) of organic molecules, we have collected all the reliable CPL, as well as the corresponding circular … Abstract Prompted by the recent rapid growth of interest in circularly polarized luminescence (CPL) of organic molecules, we have collected all the reliable CPL, as well as the corresponding circular dichroism (CD), data measured in fluid solutions. To analyze the correlation between CPL and CD, we employed the absorption and luminescence dissymmetry factors (g abs and g lum ) of the π–π* transition reported for chiral organic molecules of various categories, including planar chiral cyclophanes and helicenes, axially chiral biaryls and spiro compounds, and point‐ and axially chiral BODIPY derivatives. In rigid π‐systems, the absorption and fluorescence spectra are often mirror images of each other with a small Stokes shift, reflecting the minimal conformational relaxation in the emissive excited state, which should also affect the chiroptical properties in the excited state and be better sensed by CPL. However, no comprehensive efforts have hitherto been made to correlate the two relevant chiroptical properties, i. e. CPL versus CD, and also to quantitatively elucidate the effects of conformational relaxation in the excited state on the CPL behavior. The global linear regression analysis of all the reported g abs and g lum values, though fairly scattered (see TOC), led us to a quantitative relationship: |g lum |=0.81×|g abs | ( r 2 =0.60), which demonstrates that the CPL dissymmetry factor is proportional to, and smaller than, the CD dissymmetry factor. A closer look revealed that the slope of the plot, or the proportional coefficient, is a critical function of the class of compounds, varying from 0.99 for cyclophanes to 0.93 for biaryls, to 0.77 for BODIPYs, and then to 0.61 for helicenes/helicenoids. The scattered g lum –g abs plot and the general trend g lum ≤g abs appear to be inherent to the CPL of organic molecules in their isolated states, originating from the conformational flexibility, vibrational contribution, and Stokes shift that differ in each category.

Recent Progress on Circularly Polarized Luminescent Materials for Organic Optoelectronic Devices

2018-07-03

Jianmei Han , Song Guo , Hu Jie Lu +3 more

Abstract Due to the characteristics of optical rotation, selective emission of polarized light, and circular dichroism, circularly polarized luminescent materials have aroused extensive attentions, and they have exhibited wide optoelectronic … Abstract Due to the characteristics of optical rotation, selective emission of polarized light, and circular dichroism, circularly polarized luminescent materials have aroused extensive attentions, and they have exhibited wide optoelectronic applications, such as optical data storage, liquid crystal display, and backlights in 3D displays. Here, the research progress of circularly polarized luminescent materials for organic optoelectronic devices is summarized. First, the definition and measurement of the circularly polarized light, such as optical rotatory dispersion, circular dichroism, and circularly polarized luminescence, are systematically introduced. Subsequently, the design strategies for various kinds of circularly polarized luminescent materials, including luminescent lanthanide and transition‐metal complexes, small organic luminophores, conjugated polymers, supramolecules, and liquid crystals are summarized. These materials exhibit circularly polarized luminescence with different magnitudes of luminescence dissymmetry values ( g lum ). They are further applied in optoelectronic devices with excellent performance, and the influence factors on the g lum values of these materials are presented in detail. Finally, the current opportunities and challenges in this rapidly growing research field are discussed systematically. The circularly polarized luminescent materials with large g lum and high luminescence efficiency are very promising for applications in organic optoelectronic fields.

Circularly Polarized Luminescence in Nanoassemblies: Generation, Amplification, and Application

2019-08-08

Yutao Sang , Jianlei Han , Tonghan Zhao +2 more

Abstract Currently, the development of circularly polarized luminescent (CPL) materials has drawn extensive attention due to the numerous potential applications in optical data storage, displays, backlights in 3D displays, and … Abstract Currently, the development of circularly polarized luminescent (CPL) materials has drawn extensive attention due to the numerous potential applications in optical data storage, displays, backlights in 3D displays, and so on. While the fabrication of CPL‐active materials generally requires chiral luminescent molecules, the introduction of the “self‐assembly” concept offers a new perspective in obtaining the CPL‐active materials. Following this approach, various self‐assembled materials, including organic‐, inorganic‐, and hybrid systems can be endowed with CPL properties. Benefiting from the advantages of self‐assembly, not only chiral molecules, but also achiral species, as well as inorganic nanoparticles have potential to be self‐assembled into chiral nanoassemblies showing CPL activity. In addition, the dissymmetry factor, an important parameter of CPL materials, can be enhanced through various pathways of self‐assembly. Here, the present status and progress of self‐assembled nanomaterials with CPL activity are reviewed. An overview of the key factors in regulating chiral emission materials at the supramolecular level will largely boost their application in multidisciplinary fields.

An sp-hybridized all-carboatomic ring, cyclo[18]carbon: Electronic structure, electronic spectrum, and optical nonlinearity

2020-05-10

Zeyu Liu , Tian Lu , Qinxue Chen

Polycyclic aromatic hydrocarbons

1998-05-01

Intermolecular interaction characteristics of the all-carboatomic ring, cyclo[18]carbon: Focusing on molecular adsorption and stacking

2020-09-19

Zeyu Liu , Tian Lu , Qinxue Chen

Introduction: Aromaticity

2001-05-01

Paul von Ragué Schleyer

ADVERTISEMENT RETURN TO ISSUEPREVEditorialNEXTIntroduction: AromaticityPaul von Ragué SchleyerView Author Information University of Georgia, Athens, Georgia University of ErlangenNuremberg, GermanyCite this: Chem. Rev. 2001, 101, 5, 1115–1118Publication Date (Web):May 9, 2001Publication … ADVERTISEMENT RETURN TO ISSUEPREVEditorialNEXTIntroduction: AromaticityPaul von Ragué SchleyerView Author Information University of Georgia, Athens, Georgia University of ErlangenNuremberg, GermanyCite this: Chem. Rev. 2001, 101, 5, 1115–1118Publication Date (Web):May 9, 2001Publication History Published online9 May 2001Published inissue 1 May 2001https://pubs.acs.org/doi/10.1021/cr0103221https://doi.org/10.1021/cr0103221editorialACS PublicationsCopyright © 2001 American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views21826Altmetric-Citations667LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (30 KB) Get e-AlertscloseSUBJECTS:Aromatic compounds,Aromaticity,Electrical energy,Energy,Hydrocarbons Get e-Alerts

Dissected Nucleus-Independent Chemical Shift Analysis of π-Aromaticity and Antiaromaticity

2001-07-14

Paul von Ragué Schleyer , Mariappan Manoharan , Zhixiang Wang +4 more

Analysis of the basic π-aromatic (benzene) and antiaromatic (cyclobutadiene) systems by dissected nucleus-independent chemical shifts (NICS) shows the contrasting diatropic and paratropic effects, but also reveals subtleties and unexpected details. Analysis of the basic π-aromatic (benzene) and antiaromatic (cyclobutadiene) systems by dissected nucleus-independent chemical shifts (NICS) shows the contrasting diatropic and paratropic effects, but also reveals subtleties and unexpected details.

Aromaticity and antiaromaticity: electronic and structural aspects

1994-12-01

Владимир И. Минкин , Mikhail N. Glukhovtsev , B. I︠a︡. Simkin

Criteria of Aromaticity and Antiaromaticity. Delocalization Modes and Electron-Count Rules. Annulenes, Monocyclic Conjugated Ions, and Annulenoannulenes. Heteroaromaticity. Homoaromaticity. sigma-Aromaticity. In-Plane and Radial Aromaticity. Three-Dimensional Aromaticity. Spherical Aromaticity. Is the Physical … Criteria of Aromaticity and Antiaromaticity. Delocalization Modes and Electron-Count Rules. Annulenes, Monocyclic Conjugated Ions, and Annulenoannulenes. Heteroaromaticity. Homoaromaticity. sigma-Aromaticity. In-Plane and Radial Aromaticity. Three-Dimensional Aromaticity. Spherical Aromaticity. Is the Physical Nature of Aromaticity Known?. Index.

Effects of Countercations in Dianionic Dibenzosilepinyl Salts on the Structure and Hyperconjugative Antiaromaticity

2025-06-24

Kana Kobayashi , Takuya Kuwabara | Organometallics

Oligopyrrole-Based Anion-Responsive π-Electronic Systems That Exhibit Anion-Dependent Chiroptical Properties

2025-06-24

Vellanki Lakshmi , Yohei Haketa , Ryuma Sato +2 more | The Journal of Organic Chemistry

Dipyrromethane dimers linked via a boron-bridged 1,3-propanedione moiety exhibited efficient anion-binding abilities. Trifluoromethyl and pentafluorophenyl moieties substituted at the meso positions of dipyrromethane induced chirality in the π-electronic systems, whose … Dipyrromethane dimers linked via a boron-bridged 1,3-propanedione moiety exhibited efficient anion-binding abilities. Trifluoromethyl and pentafluorophenyl moieties substituted at the meso positions of dipyrromethane induced chirality in the π-electronic systems, whose conformations were controlled by anion binding. Anion complexes of the oligopyrrole-based chiral π-electronic systems exhibited anion-dependent chiroptical properties, as seen in circular dichroism.

Reactivity of a Methylene‐Bridged 1,3‐Bis(germylene) in Dynamic Equilibrium with Its Dimer

2025-06-23

Daichi Uchida , Mariko Yukimoto , Norihiro Tokitoh +3 more | Angewandte Chemie

We report the properties and reactivity of an unprecedented methylene‐bridged 1,3‐bis(germylene) derivative. In the solid state, it undergoes dimerization to afford a 1,2,4,5‐tetragermacyclohexa‐1,4‐diene derivative (Ge4CHD). Moreover, theoretical calculations on Ge4CHD … We report the properties and reactivity of an unprecedented methylene‐bridged 1,3‐bis(germylene) derivative. In the solid state, it undergoes dimerization to afford a 1,2,4,5‐tetragermacyclohexa‐1,4‐diene derivative (Ge4CHD). Moreover, theoretical calculations on Ge4CHD reveal σ*‐π interactions between the two π orbitals (Ge=Ge) and the CH σ* orbital. This interaction is confirmed by a significant red shift in the solid‐state UV‐vis spectrum. In contrast to the behavior in the solid state, the Ge4CHD derivative dissociates in solution into a methylene‐bridged 1,3‐bis(germylene) derivative. The resultant 1,3‐bis(germylene) derivative reacted with S8 to form a novel cage compound containing three S and two Ge atoms. On the other hand, in the reaction with triphenylphosphine sulfide, the in‐situ generated 2‐thia‐1,3‐digermabicyclo[1.1.0]butane derivative activated the benzene solvent, leading to the formation of a [2+2] cycloaddition product. Additionally, the 1,3‐bis(germylene) derivative reacted with 4‐dimethylaminopyridine (DMAP) to form a three‐membered ring. Its structural parameters and the results of theoretical calculations indicated the zwitterionic character.

Modular Synthesis of Substituted [n]Helicenes (n = 5–7) Starting from Arylmethyl Sulfone and Arylene Dialdehyde: Aldol-Type Condensation, Photocyclization, and Desulfonylative Arylation

2025-06-23

Hikaru Watanabe , Toshiki Sakami , Atsushi Iwakura +7 more | The Journal of Organic Chemistry

Bis(p-methoxyphenysulfonyl)-substituted helicenes were successfully synthesized via UV light irradiation of the corresponding (E,E)-bis(2-aryl-2-(p-methoxyphenysulfonyl)ethenyl)arylenes, which were prepared through aldol-type condensation of arylene dialdehydes with arylmethyl p-methoxypheny sulfones. By varying the combination … Bis(p-methoxyphenysulfonyl)-substituted helicenes were successfully synthesized via UV light irradiation of the corresponding (E,E)-bis(2-aryl-2-(p-methoxyphenysulfonyl)ethenyl)arylenes, which were prepared through aldol-type condensation of arylene dialdehydes with arylmethyl p-methoxypheny sulfones. By varying the combination of dialdehydes and arylmethyl p-methoxypheny sulfones, a series of helicene homologues, ranging from [5] to [7]helicenes, were obtained. The p-methoxyphenysulfonyl groups in these helicenes were efficiently replaced with Grignard reagents via Ni-catalyzed Kumada-Tamao-Corriu coupling, yielding the corresponding alkyl- and aryl-substituted derivatives. These dialkyl- and diaryl-substituted helicenes were further expanded into larger π-conjugated systems. The trimethylsilylmethyl-substituted derivative underwent sequential bromination, phosphonation, and a Wittig-Horner reaction with arylaldehydes, affording olefinic helicenes. Furthermore, FeCl3-promoted oxidative annulation of the biphenyl-1-yl-substituted derivative resulted in the formation of a "two-blade propeller" closed [6]helicene, fused with dibenzo[g,p]chrysene arrays.

Cross-Conjugated Polyenes from 2,3-Addition of [3]Cumulene

2025-06-23

| Synfacts

Unraveling electronic structure and aromaticity differences in cyclo[12]carbon (C12), B4C4N4, and B6N6 isoelectronic ring molecules

2025-06-23

Yongkang Lyu , Zhenqiang Cao , Fu-Liang Zhang +3 more | The Journal of Chemical Physics

Cyclo[12]carbon (C12) is the smallest recently synthesized carbon ring molecule that conforms to Hückel anti-aromaticity. Unraveling the electronic structure and aromaticity differences between C12 and its isoelectronic analogs (B4C4N4, B6N6) … Cyclo[12]carbon (C12) is the smallest recently synthesized carbon ring molecule that conforms to Hückel anti-aromaticity. Unraveling the electronic structure and aromaticity differences between C12 and its isoelectronic analogs (B4C4N4, B6N6) is essential for elucidating the impact of C-atom bridging and the physicochemical properties of novel ring systems. Herein, robust first-principle computational methods (including static density functional theory calculations and ab initio molecular dynamics simulations) are employed to investigate the electronic populations, bonding features, and kinetic behavior of different electron types. The molecular aromaticity is also examined by using various analytical indicators, such as anisotropy of induced current density, ZZ component of isochemical shielding surfaces, electron localization function-π, and Fermi holes. It is revealed that C12 and B4C4N4 exhibit pronounced anti-aromatic properties, while B6N6 is non-aromatic. The distinct in-plane and out-of-plane π-orbital features and differences in electronic delocalization capacity are fundamental to their anti-aromatic and non-aromatic nature, contrasting with classical aromatic molecules such as C18. This work provides valuable references for understanding the electronic structures of novel carbon ring molecules and their isoelectronic analogs that lack aromaticity, which can aid in comprehending the physicochemical properties of classic main-group elements and advance the design and synthesis of new ring molecules.

From Cycloheptatriene to Conjugated Z,Z,Z-Trienes

2025-06-23

| Synfacts

Reactivity of a Methylene‐Bridged 1,3‐Bis(germylene) in Dynamic Equilibrium with Its Dimer

2025-06-23

Daichi Uchida , Mariko Yukimoto , Norihiro Tokitoh +3 more | Angewandte Chemie International Edition

Stepwise Acetylene Insertion and Ammonia Activation at a Digallene and Diindene

2025-06-21

Álvaro García‐Romero , Israel Fernández , José M. Goicoechea | Angewandte Chemie International Edition

Sequential [2+2] cycloaddition reactions between acetylene and the digallene and diindene compounds (ETer)2 (E = Ga, In; Ter = 2,6‐Dipp2‐C6H3; Dipp = 2,6‐diisopropylphenyl) are described. Careful control of the reaction … Sequential [2+2] cycloaddition reactions between acetylene and the digallene and diindene compounds (ETer)2 (E = Ga, In; Ter = 2,6‐Dipp2‐C6H3; Dipp = 2,6‐diisopropylphenyl) are described. Careful control of the reaction conditions leads to selective formation of four‐ and six‐membered rings with 2π E2C2 and 4π E2C4 cores, respectively. A structural analysis of the heterocycles by single crystal X‐ray diffraction suggests limited electronic delocalization within the rings, which is borne out in their reactivity. For example, the six‐membered cyclohexadiene analogues exhibit Lewis‐acidic behavior and can form stable, isolable adducts with ammonia. Upon heating, these adducts transform into the corresponding bimetallic triel amides with concomitant generation of ethene.

Stepwise Acetylene Insertion and Ammonia Activation at a Digallene and Diindene

2025-06-21

Álvaro García‐Romero , Israel Fernández , José M. Goicoechea | Angewandte Chemie

Boron-Containing Chiral Spiro Molecules: Synthesis and Color-Tunable Circularly Polarized Luminescence

2025-06-20

Masahiro Ikeshita , Miku Ichinose , Jun Ono +3 more | The Journal of Organic Chemistry

Synthesis and circularly polarized luminescence (CPL) properties of boron-containing chiral spiro molecules were described. Optically pure bis(boron difluoride) complexes with spirocyclic structures were prepared from commercially available (R)- or (S)-1,1'-spirobiindane-7,7'-diol … Synthesis and circularly polarized luminescence (CPL) properties of boron-containing chiral spiro molecules were described. Optically pure bis(boron difluoride) complexes with spirocyclic structures were prepared from commercially available (R)- or (S)-1,1'-spirobiindane-7,7'-diol (SPINOL) in 3 steps. The complexes exhibited bright blue to orange circularly polarized luminescence (CPL) both in solution and in the solid state with relatively high glum (up to 3 × 10-3) values.

Benzo‐extended Thiaquasi[7]circulenes: Strategic Scholl‐type Synthesis, Tunable Electronic and Stimuli‐Responsive Properties

2025-06-20

Rajballav Dash , Sudhakar Maddala , Prabhakar Chetti +1 more | Chemistry - A European Journal

Thia‐quasi[7]circulenes (TQCs) are a novel class of π‐conjugated molecules exhibiting unique electronic, optical, and electrochemical properties. We report a highly efficient bottom‐up synthesis of TQCs via Scholl oxidative cyclization, achieving … Thia‐quasi[7]circulenes (TQCs) are a novel class of π‐conjugated molecules exhibiting unique electronic, optical, and electrochemical properties. We report a highly efficient bottom‐up synthesis of TQCs via Scholl oxidative cyclization, achieving exceptional yields and structural precision. Single‐crystal X‐ray analysis confirms their negatively curved geometry, featuring a central antiaromatic heptagonal core and a surrounding aromatic rim, leading to bifacial electronic properties. TQCs demonstrate stable redox behavior with tunable HOMO–LUMO energy levels. Their remarkable electrochemical stability highlights potential as redox‐active materials. TQCs exhibit blue‐shifted fluorescence compared to carbo‐quasi[7]circulenes, with enhanced quantum yields upon benzoannulation. Additionally, they display mechanochromic luminescence upon grinding revealing tunable molecular characteristics. These findings establish TQCs as versatile molecular frameworks, bridging fundamental chemistry and next‐generation functional materials, making them promising candidates for organic electronics, energy storage, and optoelectronic applications.

Exploring the Impact of Topological Variations on the Stability of the Ground Singlet and Lowest‐Lying Triplet States of Catacondensed Hexabenzenoids

2025-06-20

Iqra Sarfraz , Anna Roglans , Albert Artigas +1 more | European Journal of Organic Chemistry

Polycyclic aromatic hydrocarbons (PAH) like tetracenes, pentacenes, hexacenes, and some higher acenes play a central role in organic electronics due to their unique electronic properties. The impact of topological variations … Polycyclic aromatic hydrocarbons (PAH) like tetracenes, pentacenes, hexacenes, and some higher acenes play a central role in organic electronics due to their unique electronic properties. The impact of topological variations on the relative stability of PAH isomers in different electronic states is poorly understood, with limited insights into how Clar p‐sextets and topological features like bay, cove, fjord, and K‐regions influence stability in their ground singlet (S0) and lowest‐lying triplet (T1) states. In this work, we perform density functional theory calculations of the S0 and T1 states of the 37 catacondensed hexabenzenoids. We use a multivariate linear regression model with relative energy as the dependent variable and a series of topological parameters as the independent variables to quantify the effect of topology in the relative stability of the catacondensed hexabenzenoids. Our analysis shows that, in S0, stability is enhanced by an increase in the number of Clar p‐sextets and K‐regions and decreased by the presence of coves and fjords. In T1, the main stabilizing factors are the number of Clar p‐sextets and the number of rings involved in the antiaromatic region, whereas topological regions like K‐edges, bays, coves, or fjords are destabilizing.

Tuning aromaticity of cyclocarbons by heteroatom doping

2025-06-20

Luye Sun , Yuan Guo , Ihor Sahalianov +7 more | Research Square (Research Square)

<title>Abstract</title> Cyclo[<italic>n</italic>]carbons (C<italic>n</italic>) have sparked substantial interest among experimentalists and theoreticians owing to their elusive geometric structures and unique aromaticity. Composed of two-coordinated sp-hybridized carbon atoms, C<italic>n</italic> thus forms two … <title>Abstract</title> Cyclo[<italic>n</italic>]carbons (C<italic>n</italic>) have sparked substantial interest among experimentalists and theoreticians owing to their elusive geometric structures and unique aromaticity. Composed of two-coordinated sp-hybridized carbon atoms, C<italic>n</italic> thus forms two perpendicular conjugated π-electron systems, i.e., out-of-plane and in-plane. Till now, on-surface generated cyclocarbons are either doubly aromatic or doubly anti-aromatic, as the number of electrons within out-of-plane and in-plane π systems was equal. Doping with heteroatoms allows one to create two π systems with different numbers of electrons, and to tune the aromaticity. Herein, we successfully generated two heteroatom-doped cyclocarbons, C12S and C12N, and characterized their chemical and electronic structures. Calculations show that C12S exhibits out-of-plane (14 <italic>e</italic>) aromatic and in-plane (12 <italic>e</italic>) anti-aromatic character, resulting in a total non-aromaticity. For C12N, the out-of-plane (14 <italic>e</italic>) aromatic and in-plane (13 <italic>e</italic>) non-aromatic characters lead to a total aromaticity. Doping with heteroatoms may open up the field of aromaticity engineering within cyclocarbons.

Dual Excitation and Dual Emission in a 1,4‐Diazepine Bearing an Extended π‐System

2025-06-19

Lars Killian , Ayla J. H. Dekker , Björn Grabbet +4 more | Chemistry - A European Journal

We present the synthesis of a benzo[b]benzo[11,12]tetracene[5,6‐ef][1,4]diazepine ( ClBBTDZ ) and a benzo[g]phenanthro[9,10,1‐cde]indazolium ( ClBPIZ ), two novel N‐heterocyclic nanographenes. Both molecules were independently isolated from 2,3‐Dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ)‐mediated cyclodehydrogenation reaction … We present the synthesis of a benzo[b]benzo[11,12]tetracene[5,6‐ef][1,4]diazepine ( ClBBTDZ ) and a benzo[g]phenanthro[9,10,1‐cde]indazolium ( ClBPIZ ), two novel N‐heterocyclic nanographenes. Both molecules were independently isolated from 2,3‐Dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ)‐mediated cyclodehydrogenation reaction of the previously reported benzo[f,g]tetracene β‐diketiminate (ClBT‐BDI). Our mechanistic investigation shows the instrumental role of Sc(OTf)3 in allowing for C – N bond formation over N – N bond formation. Unexpectedly, ClBBTDZ shows unique dual emission and dual excitation (DE/DE) providing a combination of properties that to the best of our knowledge has not been observed before for small organic molecules. A combination of spectroscopic and computational studies provides a rationalization of these features. Charge transfer followed by geometric relaxation were found to cause the dual, strongly Stokes‐shifted emission. The understanding of both the reaction mechanism and mechanism of DE/DE can contribute to the rational design of materials with unique photophysical properties.

Coordination Chemistry Meets Boron Helices: Cationic Double-Stranded Diborahelicates and Bora[7]helicenes with Multicolor Emission

2025-06-18

Heechan Kim , Robert J. Gilliard | Journal of the American Chemical Society

Helicates and helicenes represent two prominent classes of synthetic molecular helices, desirable for their potential in chiroptical applications. Incorporating boron into their backbone presents a promising strategy to enhance the … Helicates and helicenes represent two prominent classes of synthetic molecular helices, desirable for their potential in chiroptical applications. Incorporating boron into their backbone presents a promising strategy to enhance the optical properties; however, the development of boron-doped helical systems featuring tunable emission, high configurational stability, and strong chiroptical response has been limited by synthetic challenges. We report the chemistry of bora[7]helicene and its dimeric diborahelicate. While the dimeric form is thermodynamically favored in the haloborane precursor, saturation of the boron coordination sphere by exogenous carbene or carbone ligands induces monomerization, reverting the structure to the bora[7]helicene. By employing a variety of ligands, late-stage structural diversification was achieved, yielding the first examples of cationic boron helices, which show exceptional emission tunability across the entire visible spectrum, and chiroptical responses surpassing those of previously reported [7]helicenes. Theoretical studies indicate that the double-helix geometry and the intramolecular charge transfer play a significant role in achieving high dissymmetry factors.

π-Truncation of a Parent Nanographene: Chirally Twisted Green Fluorophores

2025-06-18

Meng He , Tianyu Zhang , Ziqiang Xu +4 more | Organic Letters

The twist operation of the π-skeleton would induce left or right handedness. Herein, we report two chirally twisted C64 nanographenes designed by formally erasing two fused benzenes from a parent … The twist operation of the π-skeleton would induce left or right handedness. Herein, we report two chirally twisted C64 nanographenes designed by formally erasing two fused benzenes from a parent C76 nanographene. These C64 nanographenes possess two [6]helical units implemented around a central pyrene core in a different arrangement. The π-truncation pulls the emission bands hypsochromically from the red (C76, λmax = 612 nm) to green (C64, λmax = 505 and 506 nm) region. Curiously, the +/- sign of circularly polarized luminescence at the S1 → S0 transition was reversed between the two C64 nanographenes despite them possessing the same handedness. This is attributed to the slight difference in the arrangement of the two transition dipole moments fluctuating at around 90°, as suggested computationally.

Liquid Crystallinity and Solvophobic Interaction Drive the Differential Global Chirality in Racemic Block Copolymers†

2025-06-18

Zixiang He , Haotian Ma , Laibing Wang +2 more | Chinese Journal of Chemistry

Comprehensive Summary Natural biomolecular structures possess an inherent ability to encode chiral conformations, thus the generation and regulation of chiroptical activity is crucial. While artificial polymers hold special significance in … Comprehensive Summary Natural biomolecular structures possess an inherent ability to encode chiral conformations, thus the generation and regulation of chiroptical activity is crucial. While artificial polymers hold special significance in understanding life's origins, the fundamental connections between the racemic architecture and functional characteristics still need to be fully investigated. Herein, this study reports the generation and regulation of the global chirality and helical sense in racemic polymer systems, focusing on the synergistic effects of liquid crystallinity (LC) and solvophobic interaction. By systematically varying the length of alkyl spacers and the degree of polymerization (DP) of the core‐forming azobenzene (Azo) blocks, the chiral communications, morphological transitions and chiroptical properties of the racemic nanoaggregates can be precisely controlled. Furthermore, the proposed “first come, first serve” (FF) and the “late‐comer lives above” (LA) effect are broadly applicable and are expected to be applied to various types of racemic polymer systems. This work provides valuable insights into the design of self‐assembled systems with tunable global chirality and morphology, thereby advancing the understanding of the origins of homochirality in nature.

Unveiling Adenine H-bonded Hexads: Hierarchical Self-Assembly for Helical Columnar Functional Materials

2025-06-18

Alejandro Martínez‐Bueno , Génesis M. Valencia-Vásconez , Roberto Termine +7 more | JACS Au

The regulation of π-linker aromaticity of thiophene derivatives on cyclization and ESPT reaction

2025-06-17

Xinyu Wang , Yingrui Yin , Xiaoyang Liu +3 more | Journal of Photochemistry and Photobiology A Chemistry

Synthesis and Structures of Carbon Nanohoops Containing Three Picene Units with Each Having Two Carbomethoxy Substituents

2025-06-17

Liu Li , Stephen P. Long , Nathaniel J. Selvaraj +3 more | Organic Letters

Carbon nanohoops are an emerging class of cyclic conjugated molecules that have drawn significant attention for their unique optoelectronic properties and potential applications in nanomaterials. We report herein the synthesis … Carbon nanohoops are an emerging class of cyclic conjugated molecules that have drawn significant attention for their unique optoelectronic properties and potential applications in nanomaterials. We report herein the synthesis of two novel carbon nanohoops with structures as [9]cycloparaphenylene ([9]CPP) derivatives having three picene units with each substituted by two carbomethoxy groups. A substrate bearing a hexahydropicene unit with the two bromophenyl groups cis to each other through the Diels-Alder reaction with dimethyl acetylenedicarboxylae was prepared in four steps from 6-bromo-1-tetralone. A subsequent Ni(cod)2/bpy-mediated macrocyclization reaction followed by a DDQ-promoted oxidation step of the central six-membered ring and the dimethylene linkages produced a pair of cyclic anti- and syn-trimers because of the slow rotation of the dicarbomethoxy-substituted picene units. This work not only introduces new CPP architecture but also provides insights into the potential extension of this methodology toward the synthesis of cyclophenacenes as carbon nanobelts.

The Form of the HOMA Geometric Aromaticity Index Is Universal and Allows the Design of Electronic and Magnetic Descriptors

2025-06-17

Ján Cz. Dobrowolski , Sławomir Ostrowski | The Journal of Organic Chemistry

The HOMA geometrical aromaticity index is unique. It is simple, based on observable bond distances, and can be defined using experimental or computational bond values. Moreover, its mathematical form expresses … The HOMA geometrical aromaticity index is unique. It is simple, based on observable bond distances, and can be defined using experimental or computational bond values. Moreover, its mathematical form expresses geometric similarity to the archetypal aromatic benzene. Here, we show that HOMA is simply a kind of mean of the errors squared (MSE). This is why the index is such a good measure of aromaticity. Thus, only a slight modification grounds the HOMA index on electronic or magnetic properties, producing an electronic or magnetic molecular measure expressing electronic or magnetic similarity/dissimilarity to benzene. Based on an analysis of over 70 neutral or charged carbocyclic rings, we compare the HOMA indices based on bond distances, selected electron density properties in bond or ring critical points, chemical shifts, and spin-spin coupling constants. We conclude that using electronic and magnetic variables discloses separate trends that are invisible if CC bond lengths are used. Such new HOMA indices can be used to study different facets of aromaticity and as more general molecular structure descriptors.

Understanding Small Molecule Activation Promoted by Heavier Benzene 1,4‐diides: Interplay between Diradical Character and Aromaticity

2025-06-16

Daniel González‐Pinardo , Rajendra S. Ghadwal , Israel Fernández | Chemistry - A European Journal

The intricate relationship between diradical character, aromaticity, and reactivity in annulated heavier Group 14 benzene‐1,4‐diides, i.e. [(ADC)E]2 (E = Si, Ge, Sn), based on an anionic dicarbene framework, (ADC = … The intricate relationship between diradical character, aromaticity, and reactivity in annulated heavier Group 14 benzene‐1,4‐diides, i.e. [(ADC)E]2 (E = Si, Ge, Sn), based on an anionic dicarbene framework, (ADC = PhC{N(Ar)C}2: Ar = aryl), has been investigated through Density Functional Theory and ab initio calculations. The diradical character of both homo‐ [(ADC)E]2 and heteroleptic [(ADC)2EE'] systems (E ≠ E') has been accurately computed, while the aromaticity of their corresponding closed‐shell and open‐shell singlet states has been evaluated using magnetic descriptors. Additionally, the key factors governing dihydrogen activation and cycloaddition with acetylene have been quantitatively analyzed in detail by applying the combination of the Activation Strain Model of reactivity and Energy Decomposition Analysis methods. The findings reveal a direct correlation between reactivity and diradical character, both of which increase down Group 14.

Synthesis Amphiphilic One-Handed Helical Ladder Polymers with Circularly Polarized Luminescence

2025-06-16

Zicheng Pan , Wei Zheng | Molecules

Helical ladder polymers attract attention because of their well-defined, one-handed helical ladder structures and unique properties, which differ from precursor polymers that have random-coil conformations. However, the synthesis of helical … Helical ladder polymers attract attention because of their well-defined, one-handed helical ladder structures and unique properties, which differ from precursor polymers that have random-coil conformations. However, the synthesis of helical ladder polymers is difficult and inhibits their functions and applications. In this study, we reported the synthesis of amphiphilic optically active 2,2′-tethered binaphthyl-embedded helical ladder polymers carrying hydrophilic oligo (ethylene glycol) (OEG) as side chains through quantitative and chemoselective acid-promoted intramolecular cyclization of random-coil precursor polymers. The obtained helical ladder polymers exhibited dramatic circular dichroism (CD) and circularly polarized luminescence (CPL) enhancement. Moreover, we further established a circularly polarized fluorescence-energy transfer (CPF-ET) strategy in which the helical ladder polymers work as a donor, emitting circularly polarized fluorescence to excite an achiral fluorophore (coumarin-6) as the acceptor, producing green CPL with luminescence dissymmetry factor (2.5 × 10−4).

Twisting Chiral Aggregation‐Induced Emission Macrocycles into a Microhelix with Boosted Circularly Polarized Luminescence

2025-06-15

Sipeng Wang , Shengfu Wu , Ran Wang +2 more | Angewandte Chemie International Edition

The design and assembly of chiral macrocycles remain an underexplored frontier in supramolecular science. In this study, we synthesized a pair of enantiomeric macrocyclic molecules (CP1) through the condensation of … The design and assembly of chiral macrocycles remain an underexplored frontier in supramolecular science. In this study, we synthesized a pair of enantiomeric macrocyclic molecules (CP1) through the condensation of chiral cyclohexanediamine with tetraphenylethylene (TPE) dialdehyde. These molecules exhibited remarkable circular dichroism (CD) and circularly polarized luminescence (CPL) properties at the supramolecular level. Through supramolecular assembly in mixed solvent systems, we achieved a rare micron‐scale helical structure, exhibiting a high dissymmetry factor (glum) of 0.32—one of the highest values reported to date for macrocyclic assemblies. Furthermore, by designing a chiral macrocycle with phenyl spacers (CP2), we revealed that the confinement of macrocycles and restricted internal molecular rotation are critical for achieving high glum values and helical structure formation. This work not only advances the design of chiral macrocycles but also provides new insights into the relationship between molecular structure and supramolecular assembly, paving the way for the development of advanced chiral materials with potential applications in optics, sensing, and nanotechnology.

Twisting Chiral Aggregation‐Induced Emission Macrocycles into a Microhelix with Boosted Circularly Polarized Luminescence

2025-06-15

Sipeng Wang , Shengfu Wu , Ran Wang +2 more | Angewandte Chemie

A Universal Chiral Poly(Phenyl Isocyanate) Host for Inducing Full‐Color Circularly Polarized Luminescence of Achiral Thermally Activated Delayed Fluorescence Emitters

2025-06-15

Chen Liang , Hu Zhimin , Shuo Li +3 more | Macromolecular Rapid Communications

ABSTRACT A design strategy for preparing circularly polarized thermally activated delayed fluorescence (TADF) materials is proposed by utilizing the intermolecular interactions between chiral polymeric hosts and non‐chiral TADF emitters to … ABSTRACT A design strategy for preparing circularly polarized thermally activated delayed fluorescence (TADF) materials is proposed by utilizing the intermolecular interactions between chiral polymeric hosts and non‐chiral TADF emitters to achieve chirality transfer. A single‐handed helical polymer, poly‐DMAC, is successfully designed and synthesized, which serves as a universal chiral host to induce circularly polarized luminescence (CPL). By blending poly‐DMAC with four TADF emitters, full‐color stable CPL emission ranging from blue‐green to orange‐red is achieved, with a maximum asymmetric factor reaching the order of 10 −3 . This research demonstrates that through a simple blending method, chiral polymer hosts enable non‐chiral TADF emitters to achieve full‐color and unidirectional CPL emission, highlighting the promising prospects of helical polymers for CPL applications.

From Hückel to Clar: a block-localized description of aromatic systems

2025-06-14

Fabien Barrois , Yannick Carissan , Nicolas Goudard +2 more | Pure and Applied Chemistry

Abstract We report a local description of extended aromatic systems using Clar formalism embedded in Valence Bond-like calculations. We disclose a new implementation of our HuLiS (Hückel/Lewis) program that considers … Abstract We report a local description of extended aromatic systems using Clar formalism embedded in Valence Bond-like calculations. We disclose a new implementation of our HuLiS (Hückel/Lewis) program that considers blocks of electrons in addition to bonds and lone pairs/radical centers. The method is based on the Hückel approximation for both the empirical hamiltonian and the atomic orbital orthogonality constraint.

Tunable Synthesis of One-Handed Helical Ladder Polymers with a Helical Cavity or Helical Grooves for Advanced Chiral Recognition

2025-06-13

Tomoyuki Ikai , Takehiro Matsumoto , Shoki Takeda +2 more | Macromolecules

Pyrene-Fused Azahelicene Showing Circularly Polarized Luminescence

2025-06-13

Chihiro Maeda , Yukino Daigen , Sayaka Michishita +1 more | Organic Letters

The Scholl reaction of 3,6-bis{2-(pyren-2-yl)phenyl}carbazole produces bispyrene-fused azahelicene. The two pyrenes are arranged in a cross-stack manner with an interplanar distance of 3.34 Å, which induces bright circularly polarized luminescence … The Scholl reaction of 3,6-bis{2-(pyren-2-yl)phenyl}carbazole produces bispyrene-fused azahelicene. The two pyrenes are arranged in a cross-stack manner with an interplanar distance of 3.34 Å, which induces bright circularly polarized luminescence (CPL) in the visible region. Furthermore, the NH moiety could respond to the fluoride anion and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), leading to the CPL in the red region. The binding constant (Ka) for F- has been determined to be 3 × 105 M-1, indicating tight binding, despite a single interaction.

Spring‐Like Behavior in [8]Helicene Diimides: How Helical Pitch Governs Optical Anisotropy and Electronic Conjugation

2025-06-13

Fridolin Saal , Vincenzo Brancaccio , Krzysztof Radacki +2 more | Angewandte Chemie

Helicenes, with their corkscrew‐shaped geometry, have emerged as prototypical molecular springs for engineering chiral functional materials through precise structural modulation. Here we introduce the design and synthesis of [8]helicene diimides … Helicenes, with their corkscrew‐shaped geometry, have emerged as prototypical molecular springs for engineering chiral functional materials through precise structural modulation. Here we introduce the design and synthesis of [8]helicene diimides ([8]HDIs) and demonstrate that the helical pitch of their backbone can be precisely tuned by bridging the imide nitrogen atoms with alkyl chains of varying lengths (C3–C6). This approach constrains the molecular geometry to systematically control optical anisotropy, chiroptical response, and electronic communication. Remarkably, modulation of the helical pitch leads to high optical dissymmetry factors (up to 6.0 × 10−2) and enhanced through‐space conjugation. Furthermore, we investigate how variations in the helical pitch affect crystal packing in both enantiopure and racemic samples. Complementary quantum chemical calculations provide insights into the origins of these properties, highlighting the potential of this strategy for designing advanced chiral materials.

Carbon–Nitrogen Axial Chirality as a Novel Chiral Framework Design Strategy for Circularly Polarized Luminescence Materials

2025-06-13

Lei Zeng , Chen‐Hao Guo , Chensen Li +7 more | Aggregate

ABSTRACT Circularly polarized luminescence (CPL) materials are essential for advanced optoelectronic applications, yet efficient chiral design strategies remain challenging. Axial chirality has been widely employed in the construction of CPL … ABSTRACT Circularly polarized luminescence (CPL) materials are essential for advanced optoelectronic applications, yet efficient chiral design strategies remain challenging. Axial chirality has been widely employed in the construction of CPL materials due to its unique rigid structure. However, the focus has been primarily on the derivatives of carbon–carbon axial chirality. We herein propose a strategy for constructing carbon–nitrogen (C─N) axially chiral molecular frameworks to fully exploit the excellent chromophoric properties of nitrogen‐containing heterocycles (such as carbazole). A pair of chiral emitters, ( S / R )‐AI‐2TCFC, was designed and synthesized, exhibiting an emission peak at 578 nm both in the toluene solution and in the neat film state. It possessed typical aggregation‐induced emission (AIE), thermally activated delayed fluorescence (TADF), and a luminescence dissymmetry factor ( g lum ) of 10 −3 , demonstrating its potential for high‐performance device applications. These materials were successfully applied in circularly polarized organic light‐emitting diodes (CP‐OLEDs), demonstrating promising electroluminescence performance. This innovative strategy not only expands the design toolbox for CPL materials but also paves the way for next‐generation high‐performance optoelectronic devices.

Spring‐Like Behavior in [8]Helicene Diimides: How Helical Pitch Governs Optical Anisotropy and Electronic Conjugation

2025-06-13

Fridolin Saal , Vincenzo Brancaccio , Krzysztof Radacki +2 more | Angewandte Chemie International Edition

Oligomeric 2D nanosheets derived from starphenes

2025-06-13

Qian Liu , Glen P. Miller | MRS Advances

Assessing the Aromaticity of Fluorinated Benzene Derivatives Using New Descriptors Based on the Distributed Multipole Analysis (DMA) Partition of the Electron Density

2025-06-11

Nathália M. P. Rosa , Matheus Máximo‐Canadas , Itamar Borges | Journal of Physical Organic Chemistry

ABSTRACT We investigated the impact of fluorination on the aromaticity of 12 benzene‐based compounds using a recently proposed new set of six descriptors (ACS Omega 2025, 10, 14, 14157–1417) based … ABSTRACT We investigated the impact of fluorination on the aromaticity of 12 benzene‐based compounds using a recently proposed new set of six descriptors (ACS Omega 2025, 10, 14, 14157–1417) based on the distributed multipole analysis (DMA) partition of the electron density. These descriptors allow the quantification of electron delocalization, an observable property related to aromaticity, and were defined from the components of the DMA quadrupole moment tensor , the first electric multipole moment with out‐of‐plane contributions. We found a decrease in aromaticity that is related to the electron‐withdrawing inductive effects of fluorine substituents, which modify the electron density distribution on the ring, particularly in regions adjacent to the substituents. The analysis by the ‐based aromaticity descriptors revealed a strong correlation between electron distribution and electronic delocalization in fluorinated systems, confirming that fluorine substituents directly affect the symmetry and uniformity of electronic delocalization. A linear relationship between the descriptors and the and ring current strength () descriptors was found, suggesting that these descriptors capture similar aspects of aromaticity. These findings highlight the effectiveness and robustness of the new aromaticity descriptors for rationalizing the aromaticity of fluorinated compounds.

Thianthrene‐Based Thiapillar[6]Arene Derivatives: Design, Synthesis, and Characterization

2025-06-10

Masafumi Ueda , Moe Isozaki , Nozomi Inose +2 more | Asian Journal of Organic Chemistry

Abstract Thiapillar[6]arene is a π‐electron macrocyclic system with a benzene ring bridged at the 1,4‐positions by a sulfur atom to form a hexagonal structure. Further sulfur atoms can be bridged … Abstract Thiapillar[6]arene is a π‐electron macrocyclic system with a benzene ring bridged at the 1,4‐positions by a sulfur atom to form a hexagonal structure. Further sulfur atoms can be bridged into the molecules of this scaffold to form thianthrene moieties inside the skeleton. This promotes rigidity because of the double bridging, the molecular skeleton is distorted while maintaining the hexagonal structure, and the derivatives begin to show redox and photoluminescence behavior derived from the formed thianthrene. In this study, macrocyclic molecules I – IV, incorporating one to three thianthrene moieties in the thiapillar[6]arene skeleton, were successfully synthesized via a bottom‐up approach, and their molecular structures, molecular tiling, unique redox behavior, fluorescence, and phosphorescence properties were elucidated.