A novel three-dimensional heterometallic coordination polymer: poly[[diaquadi-μ3-chlorido-μ2-chlorido-tri-μ3-nicotinato-tricopper(I)gadolinium(III)] hemihydrate

Abstract

In the title polymeric heterometallic compound, {[Cu(3)Gd(C(6)H(4)NO(2))(3)Cl(3)(H(2)O)(2)]·0.5H(2)O}(n), comprising copper(I) and gadolinium(III) cations bridged by nicotinate (nic) ligands and chloride anions, the Gd(III) centers display a bicapped trigonal prismatic geometry, defined by six carboxylate O atoms and two water molecules. For copper(I), one Cu center is three-coordinated by three chloride ions and displays a trigonal-planar geometry; the other two Cu centers are four-coordinated and display a very distorted tetrahedral geometry. The chloride anions act in μ(2)- and μ(3)-bridging modes, linking the Cu(I) ions into an infinite chain. The nic ligand exhibits a tridentate coordination mode, with the carboxylate O atoms linking to two Gd(III) ions and the N atom linking to one Cu(I) ion. Thus, a novel three-dimensional heterometallic coordination polymer is constructed from Gd-carboxylate subunits and Cu-Cl chains. In addition, intra- and intermolecular O-H···O and O-H···Cl hydrogen bonds are also observed within the three-dimensional structure. Topologically, the framework represents an unusual 3,6-connected (4.8(2))(3)(4(10).6(5)) net.