Key indicators: single-crystal X-ray study; T = 296 K; mean (C-C) = 0.003 Å; R factor = 0.036; wR factor = 0.092; data-to-parameter ratio = 32.9.The asymmetric unit of the title compound, [Cu(C 4 H 8 NO 3 )-(C 12 H 8 N 2 )(H 2 O)]ClÁ2H 2 O, contains a complex cation, a chloride anion and two water molecules. The Cu II ion has a distorted square-pyramidal coordination geometry formed by one bidentate phenanthroline ligand, one O,N-bidentate dlthreoninate ligand and one apical water molecule. In the crystal structure, intermolecular O-HÁ Á ÁO, N-HÁ Á ÁO, N-HÁ Á ÁCl and O-HÁ Á ÁCl hydrogen bonds link the components into layers. A single weak intermolecular C-HÁ Á ÁO interaction connects these layers into a three-dimensional network. Related literature