A theoretical approach of alkyne linked reactive Intermediates: (nitrenoethynyl)alkyl silylenes

Experimentally unreachable reactive intermediates of (nitrenoethynyl)-X-silylenes, were compared and contrasted at B3LYP, HF, MP2, MP4, CCSD, and QCISD(T) levels with 6-311++G(d,p) basis set (X– Si–C≡C–N; X = H (1), Me (2), Et (3), Pr (4), i-Pr (5), and t-Bu (6)). The effect of small and bulky groups on these acetylene linked reactive intermediates were studied. All singlet (nitrenoethynyl)-X-silylene species were identified as ground states with one local closed-shell singlet germylene subunit (δ2π0) and one local closed-shell singlet nitrene subunit (π2π0) were coupled through acetylene linkage. Also, one local closed-shell singlet silylene subunit (δ2π0) and one local triplet nitrene subunit (π1π1) were connected to make triplet (nitrenoethynyl)silylenes. Quintet states were found as the most unstable species with one local triplet divalency subunit (π1π1) and also other local triplet nitrene subunit (π1π1). The species of (nitrenoethynyl)silylenes, could be applied as dipolar intermediates in mechanism identification of chemical reactions.