共查询到20条相似文献,搜索用时 15 毫秒
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Joseph Y. M. Chan Takahiro Kawata Nagao Kobayashi Dennis K. P. Ng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(8):2294-2299
Condensation of 1,8‐diamino‐3,6‐dichlorocarbazole with a series of disubstituted 1,3‐diiminoisoindolines, followed by treatment with BF3?OEt2 led to the formation of the corresponding core‐expanded boron(III) subphthalocyanine analogues. These air‐stable π‐conjugated boron(III) carbazosubphthalocyanines possess two boron‐containing seven‐membered‐ring units and a 16 π‐electron skeleton, and represent the first examples of antiaromatic boron(III) subphthalocyanine analogues as supported by spectroscopic and theoretical studies. The molecular structure of one of these compounds was unambiguously determined by single‐crystal X‐ray diffraction analysis. In contrast to typical boron(III) subphthalocyanines, which adopt a cone‐shaped structure, the π skeleton of this compound is almost planar. 相似文献
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Yemei Wang Shigeki Mori Hiroyuki Furuta Soji Shimizu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(32):11091-11095
Bis(1,3‐dithiol‐2‐ylidene)‐substituted subtriazachlorin was formed because of an unusual reaction of a 1,3‐dithiole‐2‐one‐fused subphthalocyanine in a triethylphosphite‐mediated tetrathiafulvalene synthesis. In this novel molecule, the bis(1,3‐dithiol‐2‐ylidene)ethane moiety and subtriazachlorin structure are fused, resulting in an electron‐donating ability and broad absorption in the near‐infrared region. 相似文献
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Paula Mayorga Burrezo Wangdong Zeng Michael Moos Marco Holzapfel Sofia Canola Fabrizia Negri Concepci Rovira Jaume Veciana Hoa Phan Jishan Wu Christoph Lambert Juan Casado 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(41):14609-14613
A complete experimental and theoretical study has been carried out for aromatic and quinoidal perylene‐based bridges substituted with bis(diarylamine) and bis(arylimine) groups respectively. The through‐bridge inter‐redox site electronic couplings (VAB) have been calculated for their respective mixed‐valence radical cation and radical anion species. The unusual similitudes of the resulting VAB values for the given structures reveal the intervention of molecular shapes with balanced semi‐quinoidal/semi‐aromatic structures in the charge delocalization. An identical molecular object equally responding to the injection of either positive or negative charges is rare in the field of organic π‐conjugated molecules. However, once probed herein for perylene‐based systems, it can be extrapolated to other π‐conjugated bridges. As a result, this work opens the door to the rational design of true ambipolar bulk and molecular conductors. 相似文献
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Chi‐Shin Wang Yu‐Chen Wei Kai‐Hsin Chang Pi‐Tai Chou Yao‐Ting Wu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(30):10264-10268
Indeno[1,2‐b]fluorene‐based [2,2]cyclophanes with 4n/4n and 4n/[4n+2] π‐electron systems were prepared, and their structures were identified by X‐ray crystallography. With short π–π distances around 3.0 Å, [2.2](5,11)indeno[1,2‐b]fluorenophane and its precursor [2.2](5,11)indeno[1,2‐b]fluorene‐6,12‐dionophane exhibit remarkable transannular interactions, leading to their unusual electrochemical and photophysical properties. With the aid of femtosecond transient absorption spectroscopy, the transition from the monomeric excited state to the redshifted H‐type dimeric state was first observed, correlating to the calculated excitonic energy splitting and the steady‐state absorption spectra induced by charge‐transfer‐mediated superexchange interaction. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(12):3280-3284
Internally 1,3‐phenylene‐ and 2,5‐thienylene‐bridged [46]decaphyrins 2 and 3 have been synthesized. While 2 shows modest aromatic character derived from the global 46π‐conjugated circuit, 3 displays larger aromatic character owing to the contribution of an (annuleno)annulene‐type network consisting of two twisted Möbius aromatic thia[28]hexaphyrin segments in addition to the global 46π‐network. Upon protonation, these [46]decaphyrins underwent large structural changes to acquire strong aromaticity. Protonated 3 has been revealed to take on a planar structure composed of fused two triangular thia[28]hexaphyrin segments. 相似文献
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Cheng Zhang Samara MedinaRivero Wuyue Liu David Casanova Xiaozhang Zhu Juan Casado 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(33):11413-11417
A tetracyano quinoidal tetrathiophene, having a central bi(thieno[3,4‐c]pyrrole‐4,6‐dione) acceptor, has been studied. The recovered aromaticity of the thiophenes produces a diradical species with cross‐conjugation between the inter‐dicyano and inter‐dione acceptor paths. A diradical character of y0=0.61 and a singlet–triplet gap of ?2.76 kcal mol?1 were determined. Competition between the two cross‐conjugated paths enhances the disjointed character of the SOMOs and results in the confinement of the diradical to the molecular center, enabling a thermodynamic diradical stabilization featuring a half‐life of 262 hours. Cross‐conjugation effects have been also addressed in the anionic species (up to a radical trianion). 相似文献
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Guangwu Li Yi Han Ya Zou Johnathan Joo Cheng Lee Yong Ni Jishan Wu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(40):14457-14464
Reported here is the step‐by‐step dearomatization of a highly aromatic polycyclic aromatic hydrocarbon (PAH), the hexa‐peri‐hexabenzocoronene (also called as “superbenzene”), to give a series of superbenzoquinones containing two, four, and six ketone groups. Different from traditional PAH‐based quinones, these superbenzoquinones show open‐shell multiradical character by rearomatization in the open‐shell forms as experimentally validated by X‐ray crystallographic analysis, NMR and ESR spectroscopy, and FT‐IR measurements, as well as theoretically supported by restricted active space spin‐flip calculations. These compounds exhibit structure‐ and molecular‐symmetry‐dependent optical, electrochemical, and magnetic properties. 相似文献