Conformational analysis and Kerr effect studies of tricarboxylic aliphatic esters

Abstract

The electronic polarizations, dipole moments, and molar Kerr constants of tricarboxylic aliphatic esters H(CH₂)_nC(CO₂Et)₃ with n= 1–8, in benzene and carbon tetrachloride at 25 °C, are recorded. The PCILO method has been used to deduce the preferred gas-phase conformations. The preferred solution-state conformation of derivatives with n= 1 and 2, indicated by the analysis of experimental and calculated electronic polarizations, dipole moments, and molar Kerr constants, is shown to be consistent with the predictions based on quantum chemical calculations. The experimental data for the investigated tricarboxylic esters can be interpreted in terms of a ‘propeller-type’ conformation with 120° < τ₁=τ₂=τ₃ < 140°.