The crystal structure of szenicsite, Cu3MoO4(OH)4

The crysta! structure of szenicsite, Cu3MoO4(On)4, orthorhombic, a = 8.5201(8), b = 12.545(1), c = 6.0794(6) A, V = 649.8(2) ~3, space group Pnnm, Z = 4, has been solved by direct methods and refined by least-squares techniques to an agreement index (R) of 3.34 % and a goodness-of-fit (S) of 1.11 for 686 unique observed [14 ~> 4CrF] reflections collected using graphite-monochromated Mo-K ~ X-radiation and a CCD area detector. The structure contains three unique Cu 2 § positions that are each coordinated by six anions in distorted octahedral arrangements; the distortions of the octahedra re due to the6+ Jahn-Teller.. effect associated with " a d 9 metal in an octahedral ligand-field. The single unique Mo potation is tetrahedrally coordinated by four 02- anions. The Cu2+~6 (4: unspecified ligand) octahedra share trans edges to form rutile-like chains, three of which join by the sharing of octahedral edges to form triple chains that are parallel to [001]. The MoO4 tetrahedra re linked to either side of the triple chain of Cu2+qb6 octahedra by the sharing of two vertices per tetrahedron, and the resulting chains are cross-linked through tetrahedral-octahedral vertex sharing to form a framework structure. The structure of szenicsite is closely related to that of antlerite, Cu3SO4(OH)4, which contains imilar triple chains of edge-sharing Cu2 § octahedra