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-dimethyl-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 group Pa3, Z = 8, d(calc) = 1.842 g/cm(3), C12H28Cl6Cu3N12O2, Syntex P2(1), lambda CuKa, 3277 I-hkl measured, including 936 independent nonextinct 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)) = 0.1899 for 831 F-hkl > 4 sigma(F). the copper atoms are linked by three bridging bidentate ligands into a regular triangle; the ligands are coordinated 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 heavily distorted octahedron (2N, O, Cl) + Cl + O. The chemical formula of the compound is discussed. an unambiguous choice between the formulas (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 atoms were not localized experimentally.