An excursion in the second-order nonlinear optical properties of platinum complexes

Electrooptical devices and optical communications need compounds with second-order nonlinear (NLO) properties as construction blocks. Typically, to show a large quadratic hyperpolarizability, compound should be asymmetric, characterized by variation between the dipole moments in excited ground states, have low energy electronic transitions. For example, hyperpolarizability can reached when an electron-donor moiety is linked means of π-conjugated spacer acceptor group. In field optics, particularly attractive are coordination metal complexes because they often low-energy high-intensity intraligand (IL), ligand-to-metal (LM), metal-to-ligand (ML) charge transfer (CT) transitions, that regulated choice ligands. Among them, platinum(II) captivating. During this excursion, we will see many them. After some basic NLO notions, review presents various classes NLO-active platinum having mono- bidentate nitrogen ligands (pyridine, bipyridine, phenanthroline), dithiolenes, cyclometalated (imines, phenylpyridine, phenylbipyridine, dipyridylbenzene), alkynyl It shown how regulate suitable photomodulate dithienylethene (DTE) moiety. Some examples redox-switchable also given. Although accent on measured solution, it nano-organized afford thin films properties. The report not comprehensive, but allows get into understand their potential.