排序方式: 共有139条查询结果,搜索用时 15 毫秒
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Srgio R. Domingos Kvin Martin Narcis Avarvari Melanie Schnell 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(33):11379-11383
We report on the one‐ and two‐water clusters of [4]helicene, the smallest polycyclic aromatic hydrocarbon with a helical sense, which were captured in the gas phase using high‐resolution rotational spectroscopy. The structures of the complexes are unambiguously revealed using microwave spectra of isotopically enriched species. In the one‐water cluster, the apparent splitting pattern is consistent with a tunneling motion that encompasses an exchange of strongly and weakly bonded water hydrogens. This motion is “locked” in the two‐water cluster. The relevant intermolecular contacts, symmetry, and aromaticity effects are unveiled for the microsolvated chiral topologies. These observations entail the first glance at the structures and internal dynamics of the water binding motifs of a chiral polycyclic aromatic hydrocarbon. 相似文献
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Wangdong Zeng Zhe Sun Tun Seng Herng Tho P. Gonalves Tullimilli Y. Gopalakrishna Kuo‐Wei Huang Jun Ding Jishan Wu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(30):8757-8761
The challenging synthesis of a laterally extended heptazethrene molecule, the super‐heptazethrene derivative SHZ‐CF3 , is reported. This molecule was prepared using a strategy involving a multiple selective intramolecular Friedel–Crafts alkylation followed by oxidative dehydrogenation. Compound SHZ‐CF3 exhibits an open‐shell singlet diradical ground state with a much larger diradical character compared with the heptazethrene derivatives. An intermediate dibenzo‐terrylene SHZ‐2H was also obtained during the synthesis. This study provides a new synthetic method to access large‐size quinoidal polycyclic hydrocarbons with unique physical properties. 相似文献
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Anthony Jolly Dandan Miao Maxime Daigle Prof. Dr. Jean-François Morin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(12):4652-4661
The solution-phase synthesis is one of the most promising strategies for the preparation of well-defined graphene nanoribbons (GNRs) in large scale. To prepare high quality, defect-free GNRs, cycloaromatization reactions need to be very efficient, proceed without side reaction and mild enough to accommodate the presence of various functional groups. In this Minireview, we present the latest synthetic approaches for the synthesis of GNRs and related structures, including alkyne benzannulation, photochemical cyclodehydrohalogenation, Mallory and Pd- and Ni-catalyzed reactions. 相似文献
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Dr. Luka Ðorđević Cataldo Valentini Dr. Nicola Demitri Cécile Mézière Magali Allain Prof. Dr. Marc Sallé Dr. Andrea Folli Prof. Dr. Damien Murphy Samuel Mañas-Valero Prof. Dr. Eugenio Coronado Prof. Dr. Davide Bonifazi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(10):4135-4143
Herein we report an efficient synthesis to prepare O-doped nanographenes derived from the π-extension of pyrene. The derivatives are highly fluorescent and feature low oxidation potentials. Using electrooxidation, crystals of cationic mixed-valence (MV) complexes were grown in which the organic salts organize into face-to-face π-stacks, a favorable solid-state arrangement for organic electronics. Variable-temperature electron paramagnetic resonance (EPR) measurements and relaxation studies suggest a strong electron delocalization along the longitudinal axis of the columnar π-stacking architectures. Electric measurements of single crystals of the MV salts show a semiconducting behavior with a remarkably high conductivity at room temperature. These findings support the notion that π-extension of heteroatom-doped polycyclic aromatic hydrocarbons is an attractive approach to fabricate nanographenes with a broad spectrum of semiconducting properties and high charge mobilities. 相似文献