Syntheses, crystal structures and magnetic properties of three cyanide-bridged iron(III)-manganese(II) binuclear complexes based on dicyanideferrite(III) building blocks

摘要

Three cyanide-bridged Fe~(III)-Mn~(II) binuclear complexes [Mn(phen)2Cl][Fe(bpmb)(CN)2]-H2O (I), [Mn-(phen)2Cl][Fe(bpdmb)(CN)2]H2O (2) and [Mn(phen)2Cl]-[Fe(bpClb)(CN)2]·3H2OEtOH (3) [phen = 1,10-phenan-throline, bpmb~(2-) = 1,2-bis(pyridine-2-carboxamido)-4-methyl-benzenate, bpdmb~(2-) = 1,2-bis(pyridine-2-carbox-amido)-4,5-dimethyl-benzenate, bpClb~(2-) = 1,2-bis(pyridine-2-carboxamido)-4-chloro-benzenate)] have been synthesized by the reaction of Mn(phen)2Cl2 with K[Fe(L)(CN)2]. The syntheses, crystal structures and magnetic properties of the complexes have been investigated. Single-crystal X-ray diffraction analysis reveals that all three complexes are binuclear complexes and contain Fe~(III)-C ≡ N-Mn~(II) linkages. Magnetic investigations indicate antiferromagnetic coupling between low-spin Fe(III) and high-spin Mn(II) centers through cyanide bridging, with J_(MnFe) = —1.39(5) cm~(-2) for 1, J_(MnFe) = —3.33(2) cm~(-1) for 2 and J_(MnFe) = — 1.96(5) cm~(-1) for 3. The magneto-structural relationships for cyanide-bridged Fe~(III)-Mn~(II) systems are discussed based on binuclear Fe~(III)-Mn~(III and trinuclear Fe~(III)-Mn~(II)-Fe~(III) magnetic models.