An ab initio study on the possibility of utilizing cationic and anionic cyanovinyl compounds as synthons

Using ab initio methods and flexible basis sets we examined neutral, cationic and anionic alpha- and beta-cyanovinyl systems and their isomeric structures to explore the possibility of their serving as synthons. The structures and relative stability of lowest energy isomers matching the (C3H2N)0/+/- formulas were investigated and discussed. The alpha-cyanovinyl form was identified as the most stable structure in the case of neutral radical and closed-shell anion, whereas the (HC---C-C---NH)+ structure, lacking a vinylic-type structural motif, was found to represent the lowest energy isomer of the cation. Regardless of the total system charge, the beta-cyanovinyl isomers were found to correspond to higher energy isomers. The electronic and thermodynamic stability of the alpha-cyanovinyl anion was confirmed, suggesting its potential as a promising candidate for serving as a logical synthon in synthesis planning, thereby eliminating the need for substituting it with a synthetic equivalent.