Two types of carboxylate-bridged copper(II)âlanthanide(III) complexes, [CuLn(C5H5N+CH2CO2â)5(H2O)5][ClO4]5· 2H2O 1 (LnIII = LaIII a or NdIII b) and [Cu3Nd2(C5H5N+CH2CO2â)10(NO3)2(H2O)8][ClO4]10·4H2O 2, have been synthesized and characterized by X-ray structural analysis. Complexes 1a and 1b are isomorphous. In both, a CuII atom is quadruply bridged to a LnIII atom by four µ-carboxylate groups at the basal positions, and co-ordinated by an aqua ligand at the apical position to form a square-pyramidal CuO4(OH2) geometry, while the LnIII atom is co-ordinated in a monocapped square antiprism by five carboxy oxygen atoms and four aqua ligands. In 2, a pair of CuII atoms in two centrosymmetrically related tetrakis(µ-carboxylate)-bridged dinuclear CuIINdIII subunits is each linked to the central CuII atom by a single syn-antiµ-carboxylate bridge, resulting in a pentanuclear cation. The central CuII atom is co-ordinated by two carboxy oxygen atoms and two aqua ligands in a distorted square-planar fashion; the other two CuII 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-antiµ-carboxylate group at the apical position. The NdIII atom is co-ordinated in a distorted monocapped square antiprism by the four carboxy oxygen atoms, three aqua ligands and a chelate nitrate group.
两种羧基桥联的
铜(II)
镧系(III)配合物、[1 (LnIII=LaIII a 或 NdIII b)和 [Cu3Nd2(
C5H5N+CH2CO2â)10(
NO3)2(
H2O)8][ClO4]10Â-4 2。络合物 1a 和 1b 是同构物。在这两种络合物中,一个 CuII 原子与一个 LnIII 原子在基底位置通过四个µ-
羧酸基团四重桥接,并在顶端位置与一个
水配体配位,形成一个正方四棱柱的
CuO4(OH2) 几何结构,而 LnIII 原子则通过五个羧基
氧原子和四个
水配体配位成一个单帽正方反四棱柱。在 2 中,两个中心对称的四(µ-
羧酸)桥接双核 CuIINdIII 亚基中的一对 CuII 原子分别与中心 CuII 原子通过单个同步反µ-
羧酸桥连接,从而形成一个五核阳离子。中心 CuII 原子由两个羧基
氧原子和两个
水配位体以扭曲的方形平面方式配位;其他两个 CuII 原子采用相同的方锥体几何形状,每个原子在基底平面由四重
羧酸桥的四个
氧原子配位,在顶端位置由合成反µ-
羧酸基团的一个
氧原子配位。NdIII 原子与四个羧基
氧原子、三个
水配体和一个
硝酸螯合基团配位成扭曲的单帽方形反三棱镜。