Correlations between molecular structures and third-order non-linear optical functions of heterothiometallic clusters: A comparative study

This contribution presents an overview of the structural features and third-order optical non-linearities of the principal classes of transition heterothiometallic clusters, and demonstrates how synthetic coordination chemistry can offer a very large variety of NLO performances in relation to the different applicable heavy transition metals and the cluster configurations, the molecular symmetry and structural rigidity of the cluster compounds, the size of the energy gap between HOMO and LUMO as well as the π-donating peripheral ligands. Such clusters can very well satisfy the different heavy demands of third-order NLO materials such as absorption, refraction, switch and most importantly, optical limiting, depending on the subtle interplay of structure-function relationships. Correlations between the structural characteristics and the non-linear optical functions of these heterothiometallic clusters are discussed and examined. Recent advances and perspectives of these clusters as NLO materials are also described.