Tris(trimethylsilyl)cyclopropenylium Cation: The First X-ray Structure Analysis of an α-Silyl-Substituted Carbocation

摘要

The X-ray crystal structure analysis of tris(trimethylsilyl)cyclopropenylium cation 2 is presented and compared with the structure and bonding properties obtained by quantum mechanical ab initio calculations. The calculated bond lengths for 2 are in good agreement with the experimentally determined ones. The effect of tris-silyl and tris-methyl substitution on the stability of the tris-substituted cyclopropenylium ions are calculated by using the isodesmic hydride transfer reaction 1. The pK_R+ value of 2 is predicted to be 4.