Dipole moments, Kerr constants and other properties of acetoacetic ester and acetylacetone

Abstract

The proportions of the keto and en01 isomers of ethyl acetoacetateand of acetylacetone incyclohexane, carbon tetrachloride and benzene have been determined by n.m.r. spectroscopy, and expressed as functions of the solute concentrations. Routine methods sufficed for all other observations, except those of electric birefringence, which needed to be examined by a pulsed-voltage technique. The dipole moments and molar Kerr constants so obtained are analysed to provide corresponding data for the separate tautomers. Possible conformations of these keto and en01 molecules can be inferred from considerations involving known bond polarities and anisotropic polarizabilities.