ETHYLENEDIAMMONIUM BIS[COPPER(II) MONOHYDROGENDIPHOSPHATE ETHYLENEDIAMINE] TRIHYDRATE

Chemical preparation, calorimetric studies, crystal structure, and IR absorption spectra are given for a new metal-organic diphosphate. From a structural point of view the title compound Cu2(C2N2H10)(HP2O7)2(C2 N2H8)2 . 3H2O is an intricate stacking of copper(II) atoms, ethylenedi ammonium groups, HP2O7(4-) anions, and both ethylenediamine and water molecules. This layered arrangement has a monoclinic unit cell with a = 18.808(8) angstrom, b = 9.631(2) angstrom, c = 14.019(8) angstrom, a nd beta = 109.63(5)degrees. The space group is C2/c and z = 4. As in a ll atomic arrangements including acidic diphosphate groups one observe s the formation of an infinite network of anions connected by strong H -bonds, infinite (HP2O7)n chains parallel to the b direction, for the present structure. The copper atom has a square-pyramidal fivefold coo rdination built by two nitrogen atoms, two oxygen atoms, and one water molecule. Another interesting feature of the title compound is the co existence of both ethylenediammonium groups and ethylenediamine molecu les in the atomic arrangement. A chelated complex of the formula [Cu(C 2H8N2)(HP2O7)(H2O)]- is observed. (C) 1994 Academic Press, Inc