Second-order nonlinear optical properties of push-pull bis(phenylethynyl)benzenes and unsymmetric platinum bis(phenylacetylide) complexes

A series of unsymmetric pi-donor-acceptor (D/A) bis(phenylethynyl)benzenes was prepared in a two-step sequence via Pd/Cu catalyzed cross-coupling reactions of 1,4-diiodobenzene and the corresponding 4-p-R-phenylethynes. Related unsymmetric D/A platinum trans-bis(acetylide) complexes were also prepared in a stepwise fashion. An investigation of their linear and nonlinear optical properties reveals excellent tradeoff in terms of nonlinearity versus transparency for these classes of chromophores.