THEORETICAL STUDY OF ELECTRONIC EFFECTS ON NOVEL (NITRENENOETHYNYL)METHYLENES

Different triplet minima are formed by coupling of a local carbene with a local nitrene through an acetylene linkage (X-C-C≡C-N, where X = H (1), CN (2), OH (3), NH2 (4), NO2 (5), CHO (6)), which are rather experimentally unreachable. The local open-shell singlet carbene (δ1π1) which coupled with the local triplet nitrene (π1π1) gives triplet minima for 1t, 2t, and 6t. The local closed-shell singlet carbene (δ2π0) which coupled with the local triplet nitrene (π1π1) gives triplet minima for 3t, 4t, and 5t. All triplets are more stable than their corresponding quintets. The quintet minima are formed by coupling of a local triplet carbene with a local triplet nitrene. Due to coupling of open shell singlet carbene and open shell singlet nitrene subunits appear a neutral molecule with X–C≡C–C≡N formula, and show about 45.9-78.0 kcal/mol more stability than he corresponding triplet states. The results are compared at six Ab initio and DFT levels using 6-311++G(d,p) basis set.

Keywords:

(Nitrenoethynyl)-X-methylene , Triplet , Quintet , Carbene , Nitrene , DFT