Metal-centric organic compounds: boon to third-order nonlinear optical applications

Abstract In the recent past the molecular engineering of coordination metal complexes has attracted new interest in the field of nonlinear optics (NLO), which find their applications in optoelectronics and optical data storage technology it is the transition metal along with the organic moieties that induce the control over the optical nonlinearity these properties of the materials not only enhance the intensity but also have a drastic effect on the polarization of incident laser light. This is an important criterion for all-optical switching applications. Coordination metal complexes are a very good target to aim at because of their robustness, physical and chemical stability, and other variable degrees that lead to an increment in NLO responses, most importantly all these properties can be either manipulated or tailored or tunable according to the requirement. Apart from the metal center, these molecules acting as legend must be chromophoric with donor-acceptor nature. In these molecules, the NLO response is intrinsically based on the ‘push-pull’ mechanism of the electrons. Obviously to these molecules, when a metal is in contact, the electronic push-pull mechanism alters rendering the molecule non-symmetric. This review article mainly concentrates on small mononuclear metal complexes for NLO application.