Effects of aryl and arylethynyl substituents at the 1-position on rotational barrier around C(sp)–C(sp3) bonds and bending deformation of acetylenic carbons in bis(9-triptycyl)ethynes
作者:Shinji Toyota、Takao Yamamori、Toshiaki Makino
DOI:10.1016/s0040-4020(01)00232-0
日期:2001.4
The barriers to rotation around C(sp)–C(sp3) single bonds in (1,4-dimethyl-9-triptycyl)(1-X-9-triptycyl)ethynes [X=phenyl, mesityl, phenylethynyl, or (1-naphthyl)ethynyl] were determined by the dynamic NMR method to examine the effect of nonspherically shaped aromatic substituents on the rotationalbarriers. The rotationalbarriers increase in the order of the pheny, arylethynyl and mesityl substituted