Electronic structures of ruthenium complexes encircling non-innocent ligand assembly

Electronic structural forms of selected mononuclear and dinuclear ruthenium complexes encompassing redox non-innocent terminal as well as bridging ligands have been addressed. The sensitive valence and spin situations of the complexes have been established in the native and accessible redox states via detailed analysis of their crystal structures, electrochemistry, UV/VIS/NIR spectroelectrochemistry, EPR signatures at the paramagnetic states and DFT calculations. Mononuclear complexes exhibit significant variations in valence and spin distribution processes based on the simple modification of the non-innocent ligand frameworks as well as electronic nature of the co-ligands, sigma-donating or pi-accepting. Dinuclear complexes with modified pyrazine, p-quinone and azo-derived redox-active bridging ligands show complex features including redox-induced electron-transfer (RIET), remote metal to metal spin-interaction in a three-spin metal-bridge-metal arrangement as well as electron-transfer driven chemical transformation (EC).