Structure and stability of carboxylate complexes. Part I. The crystal and molecular structures of copper(II) glycollate, DL-lactate, 2-hydroxy-2-methylpropionate, methoxyacetate, and phenoxyacetate

Abstract

The crystal structures of bis(glycollato)copper(II), aquobis-(DL-lactato)copper(II) hemihydrate, diaquobis-(2-hydroxy-2-methylpropionato)copper(II), diaquobis(methoxyacetato)copper(II), and diaquobis(phenoxyacetato)copper(II) have been determined by three-dimensional X-ray structure analysis. All the complexes contain trans-chelate rings, which, apart from the bow-shaped lactate, are coplanar. The copper ions are in elongated tetragonally distorted octahedral environments with two exceptions: in the lactate, copper ions are in a nearly square-pyramidal five-co-ordinate environment; in the methoxyacetate, the octahedron is compressed. Details of the structures may be rationalised in terms of Jahn–Teller distortions and hydrogen-bonding.