Hyperpolarizability of the pyridine–iodine charge transfer complex

Abstract

The second order hyperpolarizability β for the classic pyridine–I₂ charge transfer complex dissolved in benzene has been measured using the technique of electric field induced second harmonic generation in solution. The measured β was found to be very large, being in fact ∼30 times larger than β for pyridine. By using Mulliken’s charge transfer theory for the ground and excited state wavefunctions and substituting them into the quantum mechanical expression for β we were able to accurately account for the experimental results.