EFFECT OF ALKYL SUBSTITUENTS ON THE HYDROGEN-BONDING AND MOLECULAR-STRUCTURES OF BENZOPHENYLHYDROXAMIC ACIDS

The effect of alkyl substitutents on the C-phenyl and/or the N-phenyl ring of benzophenylhydroxamic acids on their molecular structure and h ydrogen bonding has been investigated. The predominant configuration i n CHCl3 is determined by steric and electronic effects. Substituents o n the C-phenyl ring favour the cis configuration, while substituents o n the N-phenyl ring favour a trans configuration. These can be rationa lised on the basis of electronic effects. Bulky substituents in the C- phenyl ring give rise to a mixture of cis and transforms due to steric factors. When substituents are present on the C-phenyl ring and N-phe nyl ring the trans configuration is preferred.