Crystal structure of dibarium (ethylenediaminetetraacetato)cuprate(II) diperchlorate hexahydrate, Ba-2[Cu(Edta)](ClO4)(2)center dot 6H(2)O

Compound Ba-2[Cu(Edta)](ClO4)(2). 6H(2)O is synthesized and its crystal str ucture is determined [R = 0.0500 for 4439 reflections with I > 2 sigma(T)]. The structure consists of the [Cu(Edta)](2-) anionic complexes, hydrated b arium cations, ClO4- anions, and molecules of crystallization water, which are interlinked into a framework. The hexadentate Edta(4-) ligand coordinat es the Cu atom forming the polyhedron in a shape of a tetragonal bipyramid, which is asymmetrically stretched along the O-R-Cu-O-R, axis (Cu-O, 2.262 and 2.532 Angstrom). The mean lengths of the equatorial Cu-N and Cu-O bonds are 2.011 and 1.952 Angstrom, respectively. The anionic complex is bound t o six Ba atoms. Two independent Ba atoms have different environments; their coordination numbers are nine and ten. The Ba-O distances lie in the range 2.669-3.136 Angstrom. Layers of Ba atoms parallel to the x0z plane are dis tinguished in the structure. (C) 2000 MAIK "Nauka/Interperiodica".