[6]Cyclo-<i>para</i>-phenylmethine: An Analog of Benzene Showing Global Aromaticity and Open-Shell Diradical Character
作者:Zhengtao Li、Tullimilli Y. Gopalakrishna、Yi Han、Yanwei Gu、Liu Yuan、Wangdong Zeng、David Casanova、Jishan Wu
DOI:10.1021/jacs.9b09780
日期:2019.10.16
We report a [6]cyclo-para-phenylmethine ([6]CPPM) macrocycle, which shows benzene-like electronic properties. Its mesityl deriva-tive [6]CPPM-Mes was isolated in crystalline form. X-ray analysis reveals a C2h symmetry and the bond lengths of the ben-zenoid/quinoid rings are averaged via resonance. One averaged 1H NMR peak for the protons on the backbone was observed at room temperature, but it was
Poly(imino ketone)s as New High-Performance Polymers
作者:Ayman S. Al-Hussaini、Markus Klapper、Tadeusz Pakula、Klaus Müllen
DOI:10.1021/ma0490101
日期:2004.11.1
synthesized via palladium-catalyzedpolycondensation (Hartwig−Buchwald reaction) of aromatic dichloro or dibromo ketones with various aromatic diamines. The influence of the halogen-containing monomers, concentration, temperature, and catalyst ligands on the polycondensation reaction and on the polymer polydispersity was investigated. These polymers showed good thermal stability with high decomposition