A theoretical approach to new triplet and quintet (nitrenoethynyl)alkylmethylenes, (nitrenoethynyl)alkylsilylenes, (nitrenoethynyl)alkylgermylenes

Document Type: Research Article

Authors

1 Islamic Azad University Karaj ,Iran,Karaj

2 Department of Chemistry, Karaj branch, Islamic Azad University, Karaj, Iran

3 Young researchers and elite club, Karaj branch, Islamic Azad University, Karaj, Iran

Abstract

Experimentally unreachable reactive intermediates of triplet and quintet (nitrenoethynyl)-X-methylenes, (nitrenoethynyl)-X-silylenes, and (nitrenoethynyl)-X-germylenes were compared and contrasted at B3LYP, M06-2X, WB97XD, HF, MP2, MP4, CCSD, and QCISD(T) levels with 6-311++G(d,p) basis set (X–M–C≡C–N; M=C, Si, and Ge ; 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 triplet (nitrenoethynyl)-X-methylene species were identified as ground states with one local open-shell singlet carbene (δ1π1) and other local triplet nitrene moiety (π1π1) with 47.75-55.70 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 (δ2π0) and one local triplet nitrene moiety (π1π1) 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 1π1) and also other local triplet nitrene moiety (π1π1).

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