1,2-Diselenolene ligands and related metal complexes: Design, synthesis and applications

1,2-Diselenolene metal complexes show a variety of chemical and physical properties, such as redox activity, visible–near-infrared absorption, optical nonlinearity, conductivity, and magnetism, which render them attractive for applications spanning from new generations of devices to catalysis. This review provides an extensive report on the synthetic pathways leading to the different classes of homoleptic and heteroleptic metal complexes featuring 1,2-diselenolene ligands, discussing their structural features, properties, and main applications. A comparison between this class of coordination compounds and their much more widely investigated 1,2-dithiolene isologues illustrates similarities and differences.