Cu3(SeO3)2Cl2: a new oxochloride of copper(II) and selenium(IV)

Cu3(Se2O3)2Cl2 crystallises in the triclinic system with the space group P1̄; the cell parameters are a=6.1240(4) Å, b=7.7880(5) Å, c=8.5170(6) Å, α=92.755(4)°, β=95.735(4)°, γ=92.853(4)° and Z=2. Full-matrix least-squares refinement gave an R value of 0.05 using 2246 independent reflections. The structure consists of [Cu3O5Cl2]n sheets parallel to (001) of infinite strings of edge-sharing copper polyhedra held together by [SeO3E] tetrahedra; these sheets are connected along the c-axis by dimers of edge-shared [Cu3O2Cl2] square planes. The structure reveals a peculiar oxygen atom bonding scheme and tunnels in which the lone pair of selenium atoms and chlorine atoms interact.