Molecular design of the valence tautomeric mixed-ligand adducts of CoII diketonates with redox-active ligands

A new concept of the structural design of valence tautomeric (VT) systems involves a search for stable adducts of tetracoordinate transition metal complexes with bidentate redox-active ligands that meet the conditions of appropriate energy gaps and energy barriers between the electromeric forms of the complexes. A series of prospective VT systems has been found out based on the DFT/B3LYP*/ 6-311++G(d,p) theoretical modeling of their structures and properties. Intramolecular electron transfer between metal and ligand centers in the dinuclear VT 2:1 adducts of Co^II diketonates and redox-active tetradentate di-o-quinones is proposed as a new promising mechanistic paradigm for the design of 2-qubit molecular systems.