om7b00512_si_002.xyz (163.41 kB)
Synthesis and Reactivities of Polyhydrido Osmium Arylsilyl Complexes Prepared from OsH3Cl(PPh3)3
dataset
posted on 2017-09-25, 12:41 authored by Guomei He, Linlin Wu, Wei Bai, Jiangxi Chen, Herman H. Y. Sung, Ian D. Williams, Zhenyang Lin, Guochen JiaReactions
of silanes with transition-metal complexes are of interest
because their relevance to Si–H bond activation, the structural
properties of polyhydrides, and catalytic hydrosilylation reactions.
This work presents the results derived from reactions of arylsilanes
Ph2SiH2 and PhSiH3 with OsH3Cl(PPh3)3 (1). Reaction of 1 with 1 equiv or excess Ph2SiH2 affords
OsH3(SiClPh2)(PPh3)3 (2) or OsH4(SiClPh2)(SiHPh2)(PPh3)2 (3), respectively. These
silyl complexes are formed via the oxidative addition of Si–H
bonds and H/Cl exchange via silylene intermediates. Similarly, reaction
of 1 with excess PhSiH3 produced the analogous
bis(silyl) complex OsH4(SiClHPh)(SiH2Ph)(PPh3)2 (4). The bis(silyl) complexes are
dodecahedral tetrahydride complexes containing weak Si···H
interactions. The complex 3 reacts with PPh3 and CH3CN to selectively eliminate Ph2SiH2. Computational studies show that the preference for reductive
eliminations from 3 follows the order Ph2SiH2 > H2 > Ph2SiHCl > Ph2HSi-SiClPh2.
