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

The solvent effect on the molecular first hyperpolarizability, β, of p-nitroaniline (pNA) has been investigated. Using the hyper-Rayleigh scattering technique, we have also determined β of pNA in DMSO using 1064 nm laser radiation. This β 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 β₀. The Onsager model significantly removes the strong solvent dependence of β (or β₀) on the dielectric constant.