Synthesis of open-framework zinc phosphite structures of varying dimensionality

Abstract

Four new organically templated zinc phosphites, [(C 4N 2H 10)(C 5NH 5)][Zn 2Cl 2(HPO 3) 2], I, [(C 4N 2H 12)(C 5NH 4)] 4[Zn 6(HPO 3) 8], II, [C 3N 2H 12][Zn 2(HPO 3) 3]⋅2H 2O, III and [C 3NH 10] 2[Zn 3(HPO 3) 4], IV have been synthesized in the presence of 1(2-pyridyl)piperazine (Py-PIP), 1,2-diaminopropane (1,2-DAP) and propylamine (PA), under mild hydro/solvo thermal conditions. The structures were determined by single-crystal X-ray diffraction. The structure of I consists of ZnO 3Cl tetrahedral and HPO 3 pseudo-tetrahedral units forming four-membered rings, which are connected through their edges giving rise to a one-dimensional ladder-like structure. The structure of II consists of [Zn 6P 8H 8O 24] 4− layers formed by 4- and 8-membered rings. The layers are stacked in AAAA… fashion with the organic molecules occupying the inter-lamellar space. The structure of III consists of ZnO 4 and HPO 3 units, forming a one-dimensional ladder-like structure, which are cross-linked through another HPO 3 units forming two-dimensional layers bound by 8-T atoms (T = Zn, P). The amine and lattice water molecules occupy the inter-layer spaces. In IV, the connectivity between ZnO 4 and HPO 3 units gives rise to a three-dimensional structure. The three-dimensional framework is built up from one-dimensional corner-shared chains and two-dimensional layers with 4.8-membered apertures. All the structures, except II, were prepared under mild reaction conditions (typically <100 °C). The presence of 4-membered rings and one-dimensional ladder/chain structures in all the compounds show the importance of such units in the building up of structures of higher dimensionality.