Evidence for π bonding in the boron–thiolate compounds (2,4,6-Me<sub>3</sub>C<sub>6</sub>H<sub>2</sub>)<sub>2</sub>B(SPh) and (2,4,6-Pr<sup>i</sup><sub>3</sub>C<sub>6</sub>H<sub>2</sub>)B(SPh)<sub>2</sub>
作者:Rudolf Wehmschulte、Karin Ruhlandt-Senge、Marilyn M. Olmstead、Mark A. Petrie、Philip P. Power
DOI:10.1039/dt9940002113
日期:——
around the B–S bond of ca. 12 kcal mol–1. This value is significantly less than the 18.4 kcal mol–1 reported earlier for 1. The lower rotational barrier observed in 2 is consistent with the delocalization of the B–S π bond over the three atom BS2π system which has a similar electronic arrangement to that of an allyl anion. Crystal data at 130 K: 1, triclinic, space group P, a= 7.851(5), b= 11.685(6)
使用庞大的芳基取代基2,4,6-Me 3 C 6 H 2和2,4,6-Pr i 3 C 6 H 2可以对两种单体硼硫化合物(2,4 ,6-Me 3 C 6 H 2)2 B(SPh)1和(2,4,6-Pr i 3 C 6 H 2)B(SPh)2 2。1和2的晶体结构表示硼和硫p轨道之间的紧密排列,与π相互作用一致。此外,在1 [1.790(6)]和2 [1.801(6)Å]中的B–S距离比硼和硫的共价半径之和(考虑到离子效应)略短。变温1 H和13个为C NMR数据2表示的平均屏障围绕旋转的B-S键约 12 kcal mol –1。这个值比18.4千卡摩尔显著少是-1先前针对报告1。在2中观察到的较低的旋转障碍与在三个原子的BS 2π系统上B–Sπ键的离域一致,该系统具有与烯丙基阴离子类似的电子排列。130 K:1,三斜晶,空间群P的晶体数据,a = 7.851(5),b = 11.685(6),c