Intramolecular stabilization of the silylene center due to the donor-acceptor interaction with a valence-unbonded nitrogen atom. A theoretical consideration

摘要

The structure and thermochemistry of typical reactions of cyclic silylenes, 2,5,8-trimethyl-1-sila-2,5,8-triazacycloocta-3,6-dien-1-ylidene and 2,5,8-trimethyl-1-sila-2,5,8-triazacyclo- octa-1-ylidene, was studied by the B3LYP-D/6-311++G(3df,3pd)//B3LYP-D/6-31+G(d) method. The main forms of the silylenes are intramolecular donor-acceptor complexes in which the silylene center is coordinated to the valence-unbonded nitrogen atom. This coordination increases silylene stability and retains its reactivity almost unchanged. The data obtained indicate that the approach to the synthesis of stable and simultaneously reactive silylenes based on the intramolecular coordination of the silylene center is promising.