NONLINEAR-OPTICAL STUDIES OF GROUP-10 TRANSITION-METAL THIENYL SYSTEMS

trans-Square-planar Group 10 metal thienyl complexes were synthesized and characterized. The linear and nonlinear optical properties were st udied in solution, the latter by forward degenerate four-wave mixing a t 1.064 mum. A strong dependence of the linear and nonlinear optical p roperties on the metal centre was observed, both the lowest energy abs orption wavelength and second hyperpolarizability decreasing down the metal group. A benzothienyl analogue of the nickel complex was similar ly synthesized and characterized, both structurally and optically. The fused ring is seen to have a favourable influence on the second hyper polarizability. Polymeric analogues of the two nickel complexes were p repared by copolymerization. The lowest energy optical transitions are substantially higher than those of purely organic analogues and the m easured second hyperpolarizabilities compare very favourably, being up to 25 times larger than poly[(3-butyl)thiophene].