Cyanide-Bridged Cr~(III)Mn~(II) Binuclear Complexes Based on [Mn(phen)2]~(2+) and Dicyanidechromate(III) Building Blocks: Syntheses, Crystal Structures, and Magnetic Properties

摘要

Three new cyanide-bridged Cr~(III)Mn~(II) binuclear complexes, [Mn(phen)2Cl]fCr(bpmb)(CN)2]·H2O (1) (phen = 1,10-phenanthroline, bpmb~(2+) = 1,2-bis(pyridine-2-carboxamido)-4-methyl-benzenate), [Mn(phen)2Cl] [Cr(bpdmb)-(CN)2]·H2O (2) (bpdmb~(2+) = 1,2-bis(pyridine-2-carboxamido)-4,5-dimethyl-benzenate), and [Mn(phen)2Cl]-[Cr(bpClb)(CN)2]·CH3OH·H2O (3) (bpClb~(2+) = 1,2-bis(pyridine-2-carboxamido)-4-chloro-benzenate) were obtained based on Mn(phen)2Cl2 and a series of dicyanidechromate(III) building blocks. Single crystal X-ray diffraction analysis shows the structures of the three complexes are dimeric type with two different metal centers linked by a cyanide group from corresponding dicyanidechromate(III) building block. Magnetic investigations indicate the existence of relatively weak antiferromagnetic coupling between Cr(III) and Mn(II) ions with best-fit constants J_(CrMn) = -2.78(5) cm~(-1) for 1, J_(CrMn) = -3.02(2) cm~(-1) for 2 and J_(CrMn) = -2.27(3) cm~(-1) for 3 based on the spin exchange Hamiltonian = -2J_()CrMn)S_(Cr)S_(Mn). The magneto-structural correlation of cyanide-bridged Cr~(III)Mn~(II) complexes has been discussed at last.