Conformational Analysis of Bis[ N -alkyl- N -(2-diphenylphosphorylethyl)]amides of Diglycolic Acid

The conformational analysis of bis[ N -alkyl- N -(2-diphenylphosphorylethyl)]amides of diglycolic acid has been carried out using the methods of dipole moments, IR spectroscopy, and quantum-chemical DFT B3PW91/6-311++G(df,p) simulation. In solution, N , N -dimethyl-, N , N -dibutyl-, and N , N -dioctyl-substituted diamides of diglycolic acid exist as an equilibrium mixture of two groups of symmetrical or nonsymmetrical conformers, in some of which intramolecular contacts involving hydrogen atoms of the alkyl substituents and oxygen atoms of the ether bridge or carbonyl groups are possible.