Mixed ReVII–FeIII and ReVII–CuII Complexes Prepared by the Use of the Complex Ligand [Re(O)3(tpenH-κ3N,N″,N″′)]2+ (tpen = N,N,N′,N′-Tetrakis(2-pyridylmethyl)ethylenediamine)

Abstract

Abstract Reactions of a ReVII complex [ReVII(O)3(tpenH-κ3N,N″,N″′)](ClO4)2 ([1](ClO4)2) (tpen = N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine) that has a free bis(2-pyridylmethyl)amino group with FeIII and CuII (or CuI) complexes in solution afforded three new mixed-metal complexes. From X-ray structural analyses, the counter anions (EO4−) of the isolated complexes are a mixture of ReO4− and the original ClO4−. The former was most likely produced by the decomposition of [1]2+ during reaction. The tetranuclear ReVII–FeIII complex [{ReVII(O)3(μ-tpen-κ3N,N″,N″′:κ3N′,N″″,N″″′)}2FeIII2(μ-O)(μ-CH3COO)2]4+ ([2]4+) has an oxodi(acetato)-bridged diiron(III) unit with two [ReVII(O)3(tpen-κ3N,N″,N″′)]+ groups coordinated to each iron(III) ion. Structures of the dinuclear ReVII–CuII complexes depend on the reactants. The reactions with CuII(ClO4)2 in CH3OH/CH3CN and CuII(PPh3)2CH3CN in CH2Cl2/CH3CN afforded [ReVII(O)3(μ-tpen-κ3N,N″,N″′:κ3N′,N″″,N″″′)CuII(CH3CN)]3+ ([3]3+) and [ReVII(O)3(μ-tpen-κ3N,N″,N″′:κ3N′,N″″,N″″′)CuIICl]2+ ([4]2+), respectively. The Cu centers have an axially elongated octahedral structure with a bis(2-pyridylmethyl)amino moiety and CH3CN for [3]3+ or Cl− of solvent origin for [4]2+ coordinated in the tetragonal plane. The axial sites are occupied by two weakly coordinated EO4− ligands in [3]3+ or EO4− and bridging Cl− from a neighboring complex cation in [4]2+.