Review: Second order nonlinearities of Schiff bases derived from salicylaldehyde and their metal complexes

Current trends suggest that light, rather than electricity, will increasingly be used in the area of information technology, with potential in optical communications, data storage and computer systems. Therefore there has been a growth of interest in development of molecular second order non-linear materials. In the last few years, organometallic and coordination complexes have emerged as interesting chromophores for producing NLO materials due to the large variety of structures and diversity of electronic properties tunable by metal centre. N₂O₂ Schiff base complexes have are a promising class of efficient chromophores exhibiting large NLO responses. This review summarizes second order NLO ligands and metal complexes of Schiff bases derived from salicylaldehyde.