What a Difference Ancillary Thienyl Makes: Unexpected Additional Stabilization of the Diruthenium(III,II) but Not the Diosmium(III,II) Mixed-Valent State in Tetrazine Ligand-Bridged Complexes. Inorganic Chemistry, (42)20:6172--6174, 2003. [PUMA: complex osmium pyridyl reaction redox spectroscopy spectroscopy;ruthenium synthesis tetrazine thienyl]