In this contribution, we report the synthesis and characterization of the second order non-linear properties of a series of unconventional terpyridyl and dipyridylphenyl platinum complexes. These new platinum complexes consist of a tridentate ligand substituted by a high electron acceptor, and a chloro or an arylacetylide ligand. The hyper-Rayleigh scattering measurements reveal that these complexes display large quadratic hyperpolarizabilities reaching a dynamic value of 1460 x 10(-30) at 1064 nm esu for the best complex. This investigation also demonstrates that cyclometalated dipyridylphenyl platinum complexes greatly exhibit enhanced first hyperpolarizability with respect to analogous terpyridyl complexes.