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 α– and β–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 α–cyanovinyl form was identified as the most stable structure in the case of neutral radical and closed-shell anion, whereas the (HCCCNH)+ 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 β–cyanovinyl isomers were found to correspond to higher energy isomers. The electronic and thermodynamic stability of the α–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.