Cu-3(SeO3)(2)Cl-2: a new oxochloride of copper(II) and selenium(IV)

Cu-3(Se2O3)(2)Cl-2 crystallises in the triclinic system with the space grou p P (1) over bar; the cell parameters are a = 6.1240(4) Angstrom, b = 7.788 0(5) Angstrom, c = 8.5170(6) Angstrom, alpha = 92.755(4)degrees, beta = 95. 735(4)degrees, gamma = 92.853(4)degrees and Z = 2. Full-matrix least-square s refinement gave an R value of 0.05 using 2246 independent reflections. Th e structure consists of [Cu3O5Cl2](n) sheets parallel to (001) of infinite strings of edge-sharing copper polyhedra held together by [SeO3E] tetrahedr a; these sheets are connected along the c-axis by dimers of edge-shared [Cu 3O2Cl2] square planes. The structure reveals a peculiar oxygen atom bonding scheme and tunnels in which the lone pair of selenium atoms and chlorine a toms interact. (C) 2000 Elsevier Science Ltd. All rights reserved.