Organic and organometallic derivatives of pentaphenylbenzene, C6Ph5X: correlation of peripheral phenyl ring orientations with the steric bulk of “X”
摘要:
一系列的C6Ph5X化合物已通过X射线晶体学表征,其中X = H、Br、CO2H、CO2R、C[Formula: see text]CPh、cis-BrC=C(Br)Ph、2-脱氢紧邻基、和二茂铁基。此外,第一个五苯基苯的有机金属配合物已通过与六羰基铬反应制备,得到(η6-C6Ph5H)Cr(CO)3配合物,其中金属三脚架连接到邻位外环或中心环。晶体态的五苯基苯甲酸存在氢键二聚体;然而,取代基的立体体积不允许羧酸基直接连接,而是通过两个桥联甲醇分子连接。在固态中,笨重的C6Ph5X系统中外环的取向对“X”取代基的体积非常敏感,使得对位环的扭转角度随着“X”的体积增大而反向响应,从而使邻位环远离中心环的平面。这些观察结果对分子螺旋桨的相关运动以及最终对分子机器的影响进行了讨论。
作者:Yuchen Du、Alex McSkimming、Joel T. Mague、Robert A. Pascal
DOI:10.1002/chem.202200931
日期:2022.7.20
Tetradecaphenyl-p-terphenyl was prepared in low yield by two methods: (1) Ullmann coupling of pentaphenyliodobenzene and 2,3,5,6-tetraphenyl-1,4-diiodobenzene and (2) Diels-Alder addition of tetracyclone and 1,4-bis(phenylethynyl)-2,3,5,6-tetraphenylbenzene. Its X-ray structure shows it to possess an unusual conformation with two boat-shaped benzene rings.