Synthesis and structures of carboxylate-bridged polynuclear copper (II)-lanthanide (III) complexes (CuLn(C_5H_5N~+CH_2CO_2~-)_5(H_2O)_5)(ClO_4)_5 centre dot 2H_2O (Ln = La or Nd) and (Cu_3Nd_2(C_5H_5N~+CH_2CO_2~-)_(10)(NO_3)_2(H_2O)_8) (ClO_4)_(10) c

摘要

Two types of carboxylate-bridged copper (II)-lanthanide (III) complexes, [CuLn(C_5H_5N~+CH_2CO_2~-)_5(H_2O)_5][ClO_4]_5 centre dot 2H_2O 1 (Ln~(III) = La~(III) a or Nd~(III)) and [Cu_3Nd_2(C_5H_5N~+CH_2CO_2~-)_(10)(NO_3)_2(H_2O)_8] [ClO_4]_(10) centre dot 4H_2O 2, have been synthesized an characterized by X-ray structural analysis. Complexes 1a and 1b are isomorphous. In both, a Cu~(II) atom is quadruply bridged to a Ln~(III) atom by four #mu#-carboxylate groups at the basal positions, and co-ordinated by an aqua ligand at the apical position to form a square-pyramidal CuO_4(OH_2) geometry, while the Ln~(III) atom is co-ordinated in a monocapped square antiprism by five carboxy oxygen atoms and four aqua ligands. In 2, a pair of Cu~(II) atoms in two centrosymmetrically related tetrakis (#mu#-carboxylate)-bridged dinuclear Cu~(II)Nd~(III) subunits is each linked to the central Cu~(II) atom by a single syn-anti #mu#-carboxylate bridge, resulting in a pentanuclear cation. The central Cu~(II) atom is co-ordinated by two carboxy oxygen atoms and two aqua ligands in a distorted square-planar fashion; the other two Cu~(II) atoms adopt the same square-pyramidal geometry, each being ligated by the four oxygen atoms from the quadruple carboxylate bridges at the basal plane and by one oxygen atom of the syn-anti #mu#-carboxylate group at the apical position. The Nd~(III) atom is co-ordinated in a distorted monocapped square antiprism by the four carboxy oxygen atoms, three aqua ligands and a chelate nitrate group.