QUADRATIC HYPERPOLARIZABILITY OF 4-(DIMETHYLAMINO)BENZONITRILE IN SOLVENTS OF DIFFERING POLARITY

The hyperpolarizability beta of 4-(dimethylamino)benzonitrile has been measured by the method of electric field induced second harmonic gene ration (EFISH) at 1064 nm, in different solvents. These represented a range of dielectric constant from 2.2 to 36. 1. It had been predicted that such measurements would be influenced by, and shed some light on, a widely postulated twisted intramoleculer charge-transfer (TICT) sta te that has been deemed responsible for the dual frequency fluorescenc e of the molecule dissolved in polar solvents. Measurements of beta in these solvents showed no sensitivity to solvent polarity.