Aromatic Carbenes Research Articles

Picosecond laser studies on the effect of structure and environment on intersystem crossing in aromatic carbenes

A large solvent polarity effect on the rate of singlet to triplet intersystem crossing ( k ST) has been observed in the carbenes, diphenylcarbene (DPC) and dicycloheptadienylidene (DCHD). It is found that both k ST and the energy splitting (Δ E ST) separtaing the singlet and triplet states decrease as the solvent polarity increases for the aromatic carbenes. This “inverse” gap effect, i.e. the time for intersystem crossing decreases with increasing energy gap, is explained by an off-resonance intersystem crossing from the singlet to a sparse triplet vibronic manifold characteristic of a small energy gap. The trend in Δ E ST, which is proposed to be responsible for the variation in k ST for DPC, DCHD and structurally related aromatic carbenes, is suggested to arise from the variation in the bond angle of the central methylene carbon atom.

9-Mesityl-9,10-dihydro-9-boraanthrylidene: a probe of structure and reactivity for aromatic carbenes

Photolyse du diazo-10 mesityl-9 dihydro-9,10 bora-9 anthracene conduisant au mesityl-9 dihydro-9,10 bora-9 anthrylidene. Par irradiation directe formation de carbene singulet se transformant en triplet par conversion intersysteme. Par photosensibilisation, formation directe de carbene triplet. Spectres UV, visible

ChemInform Abstract: AROMATIC SUBSTITUTION BY FREE RADICALS, CARBENES, AND NITRENES

Chemischer InformationsdienstVolume 11, Issue 27 Reviews ChemInform Abstract: AROMATIC SUBSTITUTION BY FREE RADICALS, CARBENES, AND NITRENES R. S. ATKINSON, R. S. ATKINSONSearch for more papers by this author R. S. ATKINSON, R. S. ATKINSONSearch for more papers by this author First published: July 8, 1980 https://doi.org/10.1002/chin.198027312AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume11, Issue27July 8, 1980 RelatedInformation

ChemInform Abstract: AROMATIC SUBSTITUTION BY FREE RADICALS, CARBENES, AND NITRENES

Chemischer InformationsdienstVolume 10, Issue 16 Reviews ChemInform Abstract: AROMATIC SUBSTITUTION BY FREE RADICALS, CARBENES, AND NITRENES R. S. ATKINSON, R. S. ATKINSONSearch for more papers by this author R. S. ATKINSON, R. S. ATKINSONSearch for more papers by this author First published: April 17, 1979 https://doi.org/10.1002/chin.197916383AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume10, Issue16April 17, 1979 RelatedInformation

ChemInform Abstract: A FACILE PHOTOCHEMICALLY INDUCED ARYLCARBENE‐AROMATIC CARBENE REARRANGEMENT IN SOLUTION

AbstractAromatic Carbene Rearrangement in Solution.

A facile photochemically induced arylcarbene - aromatic carbene rearrangement in solution

A facile photochemically induced arylcarbene - aromatic carbene rearrangement in solution

Evidence for cyclopropene intermediates in the rearrangement of aromatic carbenes to arylcarbenes

Evidence for cyclopropene intermediates in the rearrangement of aromatic carbenes to arylcarbenes

Thermochemistry of carbene and nitrene rearrangements

Thermochemical estimates for aromatic carbenes and nitrenes and their interconversions are reported and allow a unifying explanation of the majority of the experimental data published to date. Chemical activation is a very important, but hitherto ignored factor in these rearrangements. This has given rise to several misinterpretations in the literature, which are now corrected.

Generation of a ten-.pi.-electron carbocyclic aromatic carbene by a carbene-carbene rearrangement

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGeneration of a ten-.pi.-electron carbocyclic aromatic carbene by a carbene-carbene rearrangementPaul H. Gebert, Roy W. King, Russell A. LaBar, and W. M. JonesCite this: J. Am. Chem. Soc. 1973, 95, 7, 2357–2359Publication Date (Print):April 1, 1973Publication History Published online1 May 2002Published inissue 1 April 1973https://doi.org/10.1021/ja00788a041RIGHTS & PERMISSIONSArticle Views60Altmetric-Citations11LEARN 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 InReddit PDF (300 KB) Get e-Alerts Get e-Alerts

Carbene-carbene rearrangements in the acenaphthylcarbene-phenalenylidene system

As a part of a continuing investigation of the interconversion of arylcarbenes and aromatic carbenes, we have studied phenalenylidene (l_) and acenaphthylcarbene (2). Originally the results of this work left much to be desired due to the abnormal properties of phenalenylidene (1) and the small yield of carbene products detected; however, the recent report of carbene 1 and its reactions' prompts a report of our results. Phenalen-l-one tosylhydrazoneL (3) was prepared from commercial phenalen-3 one (Aldrich) by the standard method3 and had properties identical to those reported previously. 134 Acenaphthylene-1-carboxaldehyde2 was synthesized from acenaphthylene by the Vilsmeir-Hack reaction. 5 In our hands this aldehyde was obtained in 24% yield as a solid (mp 55.5-57') which formed a semicarbazone with mp 241-243' (lit.5 240') and was oxidized to 1,8-naphthalic anhydride in the reported manner. 5 Acenaphthylene-l-carboxaldehyde tosylhydrazone2 (4) was obtained in the standard way. 3 Tosylhydrazones 2 and 1 were converted to sodium salts 3' and 4' with sodium hydride employing a method similar to that described previously. 3

The Ring Expansion – Ring Contraction Dichotomy in Aromatic Nitrene and Carbene Reactions I. Arylcarbenes. Preliminary communication

AbstractRearrangement experiments and energy calculations by the CNDO/2 and extende Hückel methods indicate that ring expansion and ring contraction in aromatic carbenes and nitrnes can be one‐step processes which are governed by the stabilities of the primary products and the energies of the reactants.