Coordination and organometallic compounds and inorganic–organic hybrid crystalline materials for second-order non-linear optics

This review concerns the main results obtained in the last few years by our research group at the Dipartimento di Chimica Inorganica Metallorganica e Analitica of the Universita degli Studi di Milano, in the field of non-linear optics. After a brief introduction on the basic concepts of non-linear optics (NLO), we report our investigations on the second-order NLO properties of one-dimensional (1D) and 2D coordination and organometallic compounds and hybrid inorganic–organic crystalline materials. Our research has allowed to define some general rules for the design of new appealing NLO compounds and to isolate and identify some new interesting photonic materials.