NONLINEAR-OPTICAL PROPERTIES OF TRANSITION METAL-PHOSPHINE COMPLEXES

Nonlinear optical properties of transition metal-phosphine complexes have been measured at 532 nm by degenerate four-wave mixing. Large nonresonant second-order molecular hyperpolarizabilities, gamma, have been found for complexes containing two phosphine ligands. The measured gamma values are closely related to the type and coordination geometry of the phosphine ligands. A numerical fitting of gamma values versus the number of substituents with pi-electrons on the ligand gives a result similar to what is observed for linear conjugated oligomers.