高价分子
戒指(化学)
表征(材料科学)
骨架(计算机编程)
碳骨架
化学
方位(导航)
碳纤维
立体化学
纳米技术
材料科学
有机化学
计算机科学
复合材料
试剂
复合数
人工智能
程序设计语言
作者
Yohsuke Yamamoto,Yuan Shi,Tsuneo Masui,Daigo Saito,Tatsuya Inoue,Ichiro Tanabe,Chisato Dohi,Emiko Muneta,Rong Shang,Masaaki Nakamoto
标识
DOI:10.1002/chem.202203162
摘要
To stabilize SN 2 transition state-like penta-coordinate carbon species, triaryl-substituted cationic carbon compounds bearing a moderately flexible 7-6-7-ring skeleton with sulfur donors were synthesized and characterized. Electronic effects of para substituents (R=Cl, F, H, CH3 , SMe, OMe) of the two equatorial aryl groups bound to the cationic central carbon were investigated systematically along with a planar bidentate thioxanthene derivative. X-ray analysis on their solid-state structures showed that the parent (R=H), chloro-, fluoro- and methyl-derivatives were tetracoordinate carbon (sulfonium) structures, while the p-MeO and thioxanthenyl system were pentacoordinate carbocation structures. The Hammett substituent constants for the para substituents (σp+ ) correlates well with the bonding in these compounds. The methylthio-derivative with intermediate Hammett substituent constants (p-MeS; σp+ =-0.60) showed a tetracooridnate solid-state structure, though solution UV-Vis properties suggested the presence of a penta-coordinate structure. These findings amount to the first unambiguous solution evidence of the hypervalent apical 3c-4e interactions in pentacoordinate carbon compounds.
科研通智能强力驱动
Strongly Powered by AbleSci AI