Solvent dependence of the first molecular hyperpolarizability of p-nitroaniline revisited

The solvent effect on the molecular first hyperpolarizability, beta, of p-nitroaniline (pNA) has been investigated. Using the hyper-Rayleigh scattering technique, we have also determined beta of pNA in DMSO using 1064 nm laser radiation. This beta value has not been previously reported. With the help of Onsager's theory, we have arrived at a correction factor to account for the solvent dependence of the values of the intrinsic hyperpolarizability beta(0). The Onsager model significantly removes the strong solvent dependence of beta (or beta(0)) on the dielectric constant.