Non-linear optical properties of organic molecules. Part 4. Calculations of the hyperpolarisability of sulphur-containing systems

Abstract

A parameterisation scheme has been developed for calculating the hyperpolarisability of sulphur compounds based on correlations between computed and experimental dipole moments on the one hand and the lowest energy electronic transitions on the other. The results show that sulphur behaves both as a powerful electron donor when attached to the end of a conjugated system and also is an effective transmitter of charge when part of the conjugation path itself. A good correlation is obtained between the calculated and experimental hyperpolarisabilities of two sulphur-containing molecules.