2ND HARMONIC-GENERATION BY PARA-NITROPHENOL AT WATER AIR AND WATER HEPTANE INTERFACES

Interfacial second harmonic generation by p-nitrophenol at air/water and heptane/water interfaces has been investigated. The preliminary results indicate that the orientation of the p-nitrophenol is slightly different in the two cases. but the influence of the resonant enhancement on the two important components of the molecular hyperpolarisability (beta(zzz) and beta(zxx)) differs significantly in the two systems. The difference is attributed to the change in the absorption spectrum of p-nitrophenol in heptane and water.