Several new unsymmetrical metallosalphen complexes derived from the condensation of a monoimine and salicylaldehyde in the presence of a transition metal ion as a template have been synthesized and characterized. Their linear and third-order non-linear optical (NLO) properties have been investigated in detail. With different substituted donor or acceptor groups at the 5-position of the salicylidene fragment, these metallosalophen complexes ...