The insertion reactions of the p-complex silylenoid H2SiLiF with Si-X (X=F, Cl, Br, O, N) bonds

The insertion reactions of the silylenoid H2SiLiF with SiH3XHn-1 (X=F, Cl, Br, O, N; n=1, 1, 1, 2, 3) have been studied by DFT calculations. The results indicate that the insertions proceed in a concerted manner, forming H3SiSiH2XHn-1 and LiF. The essence of H2SiLiF insertion into Si-X bonds reactions are the donations of the electrons of X into the p orbital on the Si atom in H2SiLiF and the sigma electrons on the Si atom in H2SiLiF to the positive SiH3 group. The order of reactivity by H2SiLiF insertion in vacuum indicates the reaction barriers decrease for the same-row element X from right to left and the same-family element X from up down in the periodic table. The insertion reactions in ether are similar to those in vacuum. The energy barriers in vacuum are higher than those in ether. The silylenoid insertions are thermodynamically exothermic both in vacuum and in ether.