Metal-Induced Reductive Ring Opening of 1,2,4,5-Tetrazines: Three Resulting Coordination Alternatives, Including the New Non-Innocent 1,2-Diiminohydrazido(2-) Bridging Ligand System. Inorganic Chemistry, (45)3:1316--1325, 2006. [PUMA: acetylacetonato complex;ruthenium crystal diiminohydrazido dinuclear electrochem;tetrazine induced opening prepn ring ruthenium structure]