APPLICATION OF INFRARED SPECTROMETRY TO THE STUDY OF TAUTOMERIC EQUILIBRIA AND HYDROGEN-BONDING BASICITY OF MEDICAL AND BIOCHEMICAL AGENTS - N,N'-DISUBSTITUTED AMIDINES

The hydrogen bonding basicity of 20 N,N'-disubstituted formamidines, a cetamidines and benzamidines containing the same or different groups a t the amino and imino nitrogen atoms was measured by means of the form ation constant K-HB Of their complexes with 4-fluorophenol in carbon t etrachloride. A method for the prediction of tautomeric equilibrium co nstants is proposed and was applied to unsymmetrically N,N'-disubstitu ted amidines. The results obtained were compared with those found on t he basis of pK(a) measurements in azeotropic ethanol.