Structural and Oxidation State Alternatives in Platinum and Palladium Complexes of a Redox‐Active Amidinato Ligand

Reaction of [Pt(DMSO)(2)Cl(2)] or [Pd(MeCN)(2)Cl(2)] with the electron‐rich LH=N,N’‐bis(4‐dimethylaminophenyl)ethanimidamide yielded mononuclear [PtL(2)] (1) but dinuclear [Pd(2)L(4)] (2), a paddle‐wheel complex. The neutral compounds were characterized through experiments (crystal structures, electrochemistry, UV‐vis‐NIR spectroscopy, magnetic resonance) and TD‐DFT calculations as metal(II) species with noninnocent ligands L(−). The reversibly accessible cations [PtL(2)](+) and [Pd(2)L(4)](+) were also studied, the latter as [Pd(2)L(4)][B{3,5‐(CF(3))(2)C(6)H(3)}(4)] single crystals. Experimental and computational investigations were directed at the elucidation of the electronic structures, establishing the correct oxidation states within the alternatives [Pt(II)(L(−))(2)] or [Pt(.)(L )(2)], [Pt(II)(L(0.5−))(2)](+) or [Pt(III)(L(−))(2)](+), [(Pd(II))(2)(μ‐L(−))(4)] or [(Pd(1.5))(2)(μ‐L(0.75−))(4)], and [(Pd(2.5))(2)(μ‐L(−))(4)](+) or [(Pd(II))(2)(μ‐L(0.75−))(4)](+). In each case, the first alternative was shown to be most appropriate. Remarkable results include the preference of platinum for mononuclear planar [PtL(2)] with an N‐Pt‐N bite angle of 62.8(2)° in contrast to [Pd(2)L(4)], and the dimetal (Pd(2) (4+)→Pd(2) (5+)) instead of ligand (L(−)→L ) oxidation of the dinuclear palladium compound.