The crystals of two manganese complexes [Mn(Miao)2(H2O)2]ClO4 (1) and [Mn(Miao)2- (DMF)2]ClO4 (2) [HMiao＝1-methylimidazole-2-aldoximate, DMF＝N,N-dimethylformamide] were obtained by solvent diffusion. X-ray crystallographic analyses show that the compounds crystallize in the triclinic system, space group Pī. Each Mn(III) and the coordination atoms form a slightly distorted octahedral geometry. The full-optimized molecular geometry of the HMiao ligand was calculated with Gaussian 03W program. The experimental coordinated forms of the Mn(III) in the crystals are similar to the theoretical analysis. The electrochemical properties were studied in DMF. Cyclic voltammetry exhibits redox waves at 0.75 and 0.70 V, －0.32 and －0.50 V (versus SCE) in DMF corresponding to the [MnIII]/[MnII] couples.

Key words: 1-methylimidazole-2-aldoximate, Mn(III) complex, Gaussian 03W program, electrochemical property