(2-Aminopyrimidine-κN1)aqua(pyridine-2,6-dicarboxylato-κ3O2,N,O6)copper(II): X-ray and DFT calculated structure

Abstract

In the title compound, [Cu(C7H3N2O4)(C4H5N2)(H2O)], (I), pyridine-2,6-dicarboxylate (pydc2−), 2-aminopyrimidine and aqua ligands coordinate the CuIIcentre through two N atoms, two carboxylate O atoms and one water O atom, respectively, to give a nominally distorted square-pyramidal coordination geometry, a common arrangement for copper complexes containing the pydc2−ligand. Because of the presence of Cu...Xbridgedcontacts (X= N or O) between adjacent molecules in the crystal structures of (I) and three analogous previously reported compounds, and the corresponding uncertainty about the effective coordination number of the CuIIcentre, density functional theory (DFT) calculations were used to elucidate the degree of covalency in these contacts. The calculated Wiberg and Mayer bond-order indices reveal that the Cu...O contact can be considered as a coordination bond, whereas the amine group forming a Cu...N contact is not an effective participant in the coordination environment.