A Theoretical Approach to New Triplet and Quintet (nitrenoethynyl)alkylmethylenes, (nitrenoethynyl)alkylsilylenes, (nitrenoethynyl)alkylgermylenes

Experimentally unreachable reactive intermediates of triplet and quintet (nitrenoethynyl)-X-methylenes, (nitrenoethynyl)-X-silylenes, and (nitrenoethynyl)-X-germylenes were compared and contrasted at B۳LYP, M۰۶-۲X, WB۹۷XD, HF, MP۲, MP۴, CCSD, and QCISD(T) levels with ۶-۳۱۱++G(d,p) basis set (X–M–C≡C–N; M=C, Si, and Ge; X = H (۱), Me (۲), Et (۳), Pr (۴), i-Pr (۵),  and t-Bu (۶)). The effect of small and bulky groups on these acetylene linked reactive intermediates were studied. All triplet (nitrenoethynyl)-X-methylene species were identified as ground states with one local open-shell singlet carbene (δ۱π۱) and other local triplet nitrene moiety (π۱π۱) with ۴۷.۷۵-۵۵.۷۰ kcal/mol quintet-triplet energy gap (ΔEq-t). Silylene and germylene substitutions caused the reduction of ΔEq-t. One local closed-shell singlet silylene or germylene moiety (δ۲π۰) and one local triplet nitrene moiety (π۱π۱) were connected to make triplet (nitrenoethynyl)silylenes, and (nitrenoethynyl)germylenes. The species of (nitrenoethynyl)silylenes, and nitrenoethynyl)germylenes could be applied as dipolar intermediates in mechanism identification of chemical reactions. Quintet states were found as ground states with one local triplet divalency moiety (π ۱π۱) and also other local triplet nitrene moiety (π۱π۱).

کلیدواژه ها:

Nitrenoethynyl)alkylmethylenes ، (Nitrenoethynyl)alkylsilylenes ، (Nitrenoethynyl) alkylgermylenes ، Triplet ، Quintet