Hyper-Rayleigh scattering investigation of nitrobenzyl pyridine model compounds for optical modulation of the hyperpolarisability

Hyper-Rayleigh scattering (HRS) is used to determine the molecular hyperpolarisability (β) of model compounds for the two tautomeric forms of nitrobenzyl pyridine (NBP) derivatives. For each derivative large differences (a factor of 10 to 200) are found between the two forms which indicates that the NBP system can be used to optically modulate second-harmonic generation through a photoinduced proton transfer process.