2ND-ORDER POLARIZABILITY OF P-SUBSTITUTED CINNAMIC-ACIDS

First-order hyperpolarizabilities (beta) of a series of p-substituted cinnamic acids have been measured using the hyper-Rayleigh scattering technique and compared with those of p-substituted benzoic acids. beta in these acids increases as a function of the donor strength. It incr eases twice with the increase in the effective chain length. Semi-empi rical calculations also support this enhancement. Solvents effects are dealt with at the ab initio level within the self-consistent reaction field approach.