The Influence of Structure on the Donor-Acceptor Properties of Metallodithiolene Complexes

The intrinsic charge transfer properties of a given system are dictated by their electronic structure. The movement of electrons from electron rich to electron deficient moieties of a system can spur useful photophysical properties that have been utilized in the development of materials science. Such systems take advantage of redox-active ligands, which can actively participate in electron transfer, and have the versatility to function as either electron donors or acceptors in charge transfer processes. One of the most widely used family of ligands in the development of such materials is dithiolene (Dt), which can exists in two redox extremes; reduced ene-1,2-dithiolate(2-) (Dt^2-) and oxidized dithione (Dt⁰). Dt ligands draw inspiration from the molybdenum cofactor (Moco) found in molybdenum containing enzymes that are present in all phyla of life. The Dt^2- and Dt⁰ ligands play contrasting roles in charge transfer, however, characterization of their electronic structure when both are incorporated into a coordination complex is underexplored. Detailed computational and experimental interrogation of such complexes are presented to highlight the importance of molecular and electronic structures on their charge transfer properties. Such complexes containing a Mo core are also relevant towards the comprehension of the electronic structure of Moco. This investigation focuses on the fundamental understanding of the charger transfer properties of metallodithiolene complexes containing both Dt^2- and Dt⁰ ligands, and progress towards the synthesis of the closest Moco analogs.