CRYSTAL-STRUCTURE OF THE COPPER(II) CHLORIDE COMPLEX WITH 3,5-DIMETHYL-4-AMINO-1,2,4-TRIAZOLE AND WATER

The crystal structure of the copper(II) chloride complex with 3,5-dime thyl-4-amino-1,2,4-triazole has been determined by XRD. the crystal is cubic, a = 17.754(4) Angstrom, V-cell = 5596(1) Angstrom(3), space gr oup Pa3, Z = 8, d(calc) = 1.842 g/cm(3), C12H28Cl6Cu3N12O2, Syntex P2( 1), lambda CuKa, 3277 I-hkl measured, including 936 independent nonext inct I-hkl > 0(R-int = 0.0557), an absorption correction applied using crystal habit data (mu = 82.4 cm(-1)), R(F) = 0.0711, R(wF(2)) = 0.18 99 for 831 F-hkl > 4 sigma(F). the copper atoms are linked by three br idging bidentate ligands into a regular triangle; the ligands are coor dinated by the N-1 and N-2 atoms of the triazole cycle and by the mu(3 )-bridging oxygen atom. The coordination polyhedron of copper is a hea vily distorted octahedron (2N, O, Cl) + Cl + O. The chemical formula o f the compound is discussed. an unambiguous choice between the formula s (H3O)[(mu(3)-OH)(mu eta(2)-L)(3)Cu3Cl6] and [(mu(3)-OH)(mu,eta(2)-L) (2)(mu(2) eta(2)-LH)Cu3Cl6]. H2O is impossible, since the hydrogen ato ms were not localized experimentally.