Synthesis, crystal structure and properties of a one-dimensional L-valinate bridged coordination polymer: [Cu2(L-val)2(bpy)2] n ·2nClO4·2nH2O

Abstract

The complex [Cu2(L-val)2(bpy)2] n ·2nClO4·2nH2O (L-val = L-valinate, bpy = 2,2′-bipyridine) has been synthesized and investigated by elemental analysis, IR and UV spectroscopy, DTA–TG analysis and X-ray diffraction methods. The complex crystallizes in the monoclinic space group P21 with two molecules in a unit cell of dimensions a = 10.0954(12), b = 8.1245(9), c = 23.297(3) Å, β = 102.447(2)°, V = 1865.9(4) Å3, D c = 1.614 g/cm3, μ = 1.357 mm−1, F(000) = 932, R = 0.0337, wR = 0.0847 for 7024 unique reflections. Single-crystal structure analysis reveals that cations have a one-dimensional polymeric structure, with two Cu(bpy)2+ units bridged by a carboxylate group of L-valinate. Each Cu2+ ion is in a slightly distorted square-pyramidal geometry, with the bpy(N,N′) and L-val(N,O) acting as bidentate ligands in the equatorial plane and another carboxylate oxygen atom from a symmetry-related neighboring L-valinate ion in the apical position. IR and UV spectra and thermal analysis are in agreement with the crystal structure.