SOLVENT POLARITY EFFECTS ON THE E Z CONFORMATIONAL EQUILIBRIUM OF N-1-NAPHTHYLAMIDES/

The ratio of the E and Z conformers of N-alkyl-N-1-naphthylformamides has been measured in a series of solvents using NMR spectroscopy. A li near relationship was found between the free energy of the conformatio nal equilibrium, Delta G(0), and the relative dielectric permittivity of the solvent. The comparison of NMR data with quantum-chemically cal culated SCRF heats of equilibria reveals that the solvent effect is a combination of both the electrostatic and specific solute-solvent inte ractions, the latter being directly connected to the solvent-induced s terical deformations of the solute molecule. (C) 1998 Elsevier Science Ltd. All rights reserved.