Isomeric Diruthenium Complexes of a Heterocyclic and Quinonoid Bridging Ligand: Valence and Spin Alternatives for the Metal/Ligand/Metal Arrangement. Inorganic Chemistry, (55)23:12357--12365, 2016. [PUMA: azapentacene calcn complex complex;DFT complex;EPR complex;cyclic complex;isomeric crystal diketonate dinuclear isomeric prepn;NIR quinone ruthenium spectra structure voltammetry]