Synthesis and structure of diaqua-bis(ethylenediamine)copper(II) salts with anions of carbamic acids

Two complexes of diaqua-bis(ethylenediamine)copper(II) with anions of N-carboxyglycine and ethylenediaminebiscarboxylic acid [Cu(en)(2)(H2O)](OOCCH2NHCOO). H2O (1) and [Cu(en)(2)(H2O)(2)] (OOCNHCH2CH2NHCOO).2H2O (2) were synthesized and investigated by single-crystal X-ray analysis and IR spectroscopy. Compound 1 was obtained by direct synthesis upon interaction of copper powder with glycine hydrochloride in methanol solution upon heating in air. Compound 2 was isolated as a result of a reaction between a copper(II) anionic complex with pyruvolyamide oxime (H(2)pox) of composition K[Cu(pox)(Hpox)] with ethylenediamine and formaldehyde in methanol solution. In both cases formation of carbamate anions is connected with uptake of atmospheric carbon dioxide by the reaction mixtures. The crystal structures of 1 and 2 comprise [Cu(en)(2)H2O)(2)](2+) cations, carbamic acids anions and solvate water molecules. The complex cations of 1 and 2 consist of two ethylenediamine molecules coordinated in the equatorial plane [Cu-N = 2.007(3)-2.024(3) Angstrom for 1 and 1.996(2) and 2.022(2) Angstrom for 2], and water molecules occupying the apical positions of distorted octahedra [Cu-O = 2.591(3) and 2.741(3) Angstrom for 1 and 2.556(3) Angstrom for 2]. The extended hydrogen bond system in 1 and 2 unites the elements of the structures. (C) 1997 Elsevier Science Ltd.