A NEW GENERATION OF INTERMEDIATES AT AB INITIO AND DFT LEVELS: ALLYLIC CARBENONITRENES, C=(X)C–NX=H, CH₃, COOH, F, OH, OCH₃, CF₃, CN, AND NH₂

Abstract

Linkages between vinylidene (= C :) and nitrenes (- N :), through methyne and its derivatives (CX), give allylic carbenonitrenes, C =(X) C – N , as a new brand of reactive intermediates, with conceivable singlet, triplet, or quintet ground states ( X=H , 1, X = CH 3 , 2, X = COOH , 3, X = F , 4, X = OH , 5, X X= OMe , 6, X X= CF 3 , 7, X X= CN , 8, and X X= NH 2 , 9). High-spin quintet ( 5 A ″) ground states are found for 1 and 2 at eight ab initio and DFT levels of theory. At the same levels, triplet ( 3 A ″) ground states prevail for 3–8. Low-spin singlet ( 1 A ') input structures of 1, 2, and 4–9 cyclize spontaneously through optimization to their corresponding aromatic X-azacyclopropenylidenes, with multiplicities irrelevant to allylic carbenonitrenes. Researchers may aim for generating 3–8 with triplet states, or even 1 and/or 2 with quintet states, but we do not recommend going for generation of 9 with any multiplicity, and/or formation of 1–8 with singlet states.