Ab Initio Study of Possible and Preferred Basic Site(s) in PolyfunctionalN,N¹-Dimethyl-N-cyanoformamidine

Energies of protonation and of hydrogen-bond complex formation of neutral and protonated forms with one water molecule were studied by means of ab initio calculations for polyfunctional nitrogen “push−pull” base, Me 2 N−CH N−C⋮N. Two potential basic sites, the N -imino and N- cyano were considered. Calculations with the 6-31G* basis set showed that the N -cyano site is more basic than the N -imino one for both reactions, proton-transfer and hydrogen-bonding in the gas-phase, whereas in water solution, the PCM model indicated the N -imino as the preferred basic site.