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Three complexes obtained by the reaction of Pr(Ⅲ) or Nd(Ⅲ) salts with 5-methyl-2-pyrazinecarboxylic acid(Hmpca) are structurally determined by single-crystal X-ray diffraction.Complex [Pr(mpca-)3(H2O)2]2·6H2O(1) is composed of dinuclear Pr(Ⅲ) units with two metal centers bridged by two anionic mpca-ligands in a κ3O,O’:O’ bridging mode.Complexes [Pr(mpca-)3]n(2) and [Nd(mpca-)3]n(3) are isostructures,and they consist of polymeric chains based on Ln(Ⅲ) and mpca-ligands.Each pair of adjacent metal centers is linked by three mpca-molecules in a κ3N,O:O bridging mode.
Three complexes obtained by the reaction of Pr (III) or Nd (III) salts with 5-methyl-2-pyrazinecarboxylic acid (Hmpca) are structurally determined by single-crystal X-ray diffraction. Complex [Pr H2O) 2] 2 · 6H2O (1) is composed of dinuclear Pr (Ⅲ) units with two metal centers bridged by two anionic ligands in a κ3O, O ’: O’ bridging mode.Complexes [Pr ] n (2) and [Nd (mpca-) 3] n (3) are isostructures, and they consist of polymeric chains based on Ln (III) and mpca-ligands.Each pair of adjacent metal centers is linked by three mpca- molecules in a κ3N, O: O bridging mode.