Open-framework Zinc Phosphites Research Articles

Ni(C 6N 2H 14) 2][Zn 4(H 2O)(HPO 3) 5]: A new open-framework zinc phosphite with intersecting 8-, 12- and 16-ring channels

A new three-dimensional (3-D) zinc phosphite with Zn/P ratio of 4/5, [Ni(C 6N 2H 14) 2][Zn 4(H 2O)(HPO 3) 5] ( 1), has been prepared by using self-assembled nickel complexes as the structure-directing agents. Its structure is built up from strict alternation of ZnO 4 tetrahedra and HPO 3 pseudo-pyramids, resulting in an open framework with multi-directional intersecting 8-, 12- and 16-ring channels. The unique nickel complexes Ni(DACH) 2 (DACH=1,2-diaminocyclohexane) only involving the cis-DACH acting as ligands are self-assembled under hydrothermal conditions, and act as the structure-directing agents (SDAs) to direct the formation of compound 1. Nickel complexes reside in the channels in a manner that the hydrophobic ends of the cis-DACH molecules exclusively protrude into the 16-ring pores and the amino groups closely interact with the charged inorganic framework through weak H-bonds. The interesting arrangements of nickel complexes imply a feasible approach to the design and synthesis of extra-large pore materials.

Synthesis of open-framework zinc phosphite structures of varying dimensionality

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.

Synthesis and characterization of two new open-framework zinc phosphites [ M(C 6N 4H 18)][Zn 3(HPO 3) 4] ( M=Ni, Co) with multi-directional intersecting 12-membered ring channels

Two new open-framework zinc phosphites, [ M(C 6N 4H 18)][Zn 3(HPO 3) 4] ( M=Ni, Co), have been prepared under hydrothermal conditions. Single-crystal X-ray diffraction analysis shows that [Ni(C 6N 4H 18)][Zn 3(HPO 3) 4] ( 1) and [Co(C 6N 4H 18)][Zn 3(HPO 3) 4] ( 2) are isostructural and both crystallize in the monoclinic space group C2/ c with a = 15.325 ( 3 ) Å , b = 9.792 ( 2 ) Å , c = 14.514 ( 3 ) Å , β = 109.83 ( 3 ) °, V = 2048.8 ( 7 ) Å 3 , Z = 4 , R 1 = 0.0408 ( I > 2 σ ( I ) ), and w R 2 = 0.1104 (all data) for 1, and a = 15.277 ( 2 ) Å , b = 9.8831 ( 13 ) Å , c = 14.534 ( 2 ) Å , β = 109.328 ( 2 ) ° , V = 2070.7 ( 5 ) Å 3 , Z = 4 , R 1 = 0.0380 ( I > 2 σ ( I ) ), and w R 2 = 0.1093 (all data) for 2. The structures of 1 and 2 are built up from strictly alternating ZnO 4 tetrahedra and HPO 3 pseudo-pyramids linked through oxygen vertices to form the three-dimensional (3-D) open-frameworks with multi-directional intersecting 12-membered ring (12-MR) channels. The M(TETA) ( M=Ni, Co) complexes self-assembled under hydrothermal system connect with the inorganic host via M–O–P linkages and interact with inorganic framework through weak H-bonds. The two compounds show intense photoluminescence upon photoexcitation at 235 nm.

Synthesis and characterization of a new inorganic–organic hybrid open-framework zinc phosphite: (C 6N 3H 12) 2 · Zn 5(HPO 3) 6

A new inorganic–organic hybrid open-framework zinc phosphite, (C 6N 3H 12) 2 · Zn 5(HPO 3) 6, has been hydrothermally synthesized in the presence of 1-(3-aminopropyl)imidazole amine as a structure-directing agent. Its structure was determined by single-crystal X-ray diffraction and further characterized by powder X-ray diffraction (PXRD), IR spectroscopy, ICP, elemental, and TG analyses. This compound crystallizes in the orthorhombic system, space group C222 1 (no. 20), a = 9.9512(4), b = 14.7129(6), c = 22.50660(10) Å, V = 3295.21(19) Å 3, Z = 4. The connectivity of the strictly alternating Zn-centered tetrahedra and HPO 3 pseudopyramids results in a 3D framework with intersecting 8- and 12-membered ring channels, where organic amines reside. It is worth noting that the title compound is the first metal phosphite to be prepared with a metal: phosphorus ratio of 5:6.