Solvent Dependence of the First Molecular Hyperpolarizability of p-Nitroaniline Revisited

The solvent effect on the molecular first hyperpolarizability, β, of p -nitroaniline ( p NA) has been investigated. Using the hyper-Rayleigh scattering technique, we have also determined β of p NA 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 β 0 . The Onsager model significantly removes the strong solvent dependence of β (or β 0 ) on the dielectric constant.