title: The electron transfer series [Mo(III)(bpy)3](n) (n = 3+, 2+, 1+, 0, 1-), and the dinuclear species [{Mo(III)Cl((Me)bpy)2}2(μ2-O)]Cl2 and [{Mo(IV)(tpy·)2}2(μ2-MoO4)](PF6)2⋅4 MeCN.
abstract: The electronic structures of the five members of the electron transfer series [Mo(bpy)3](n) (n = 3+, 2+, 1+, 0, 1-) are determined through a combination of techniques: electro- and magnetochemistry, UV/Vis and EPR spectroscopies, and X-ray crystallography. The mono- and dication are prepared and isolated as PF6 salts for the first time. It is shown that all species contain a central Mo(III) ion (4d(3)). The successive one-electron reductions/oxidations within the series are all ligand-based, involving neutral (bpy(0)), the π-radical anion (bpy·)(1-), and the diamagnetic dianion (bpy(2-))(2-): [Mo(III)(bpy(0))3](3+) (S = 3/2), [Mo(III)(bpy·)(bpy(0))2](2+) (S = 1), [Mo(III)(bpy·)2(bpy(0))](1+) (S = 1/2), [Mo(III)(bpy·)3] (S = 0), and [Mo(III)(bpy·)2(bpy(2-))](1-) (S = 1/2). The previously described diamagnetic dication "[Mo(II)(bpy(0))3](BF4)2" is proposed to be a diamagnetic dinuclear species [{Mo(bpy)3}2(μ2-O)](BF4)4. Two new polynuclear complexes are prepared and structurally characterized: [{Mo(III)Cl((Me)bpy(0))2}2(μ2-O)]Cl2 and [{Mo(IV)(tpy·)2}2(μ2-Mo(VI)O4)](PF6)2⋅4 MeCN.
authors: Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr (Germany), Fax: (+49) 208-306-3952.
authors: Mei
authors: M
authors: Wang
authors: Thomas
authors: T
authors: Weyhermüller
authors: Karl
authors: K
authors: Wieghardt
keywords: X-ray diffraction; electrochemistry; ligand effects; molybdenum; noninnocent ligands; pi-radical ligands