Abstract:
Three-dimensional open-framework metal selenites of the formula, [H2N(CH2)(4)NH2](0.5)[M(HSeO3)(Se2O5)] (M = Zn, Co or Ni), containing both selenite and diselenite units and intersecting 10-membered channels, have been prepared hydrothermally in the presence of piperazine. The compounds are isomorphous and crystallize in the P-1 space group. The structure is built up of MO6 dimers along with Se2O5 and HSeO3 units, the first two forming sheets, which are connected by the selenite units to yield a three-dimensional non-interpenetrating diamondoid network. The 10-membered channels have an unusual structure, being formed by 4-membered (M2Se2) and 6-membered (M2Se4) rings.
