Xuefang Zheng

Hydrothermal syntheses, crystal structures and thermal stability of two divalent metal phosphonates with a layered and a 3D structure

Two new divalent metal phosphonates, [Cu2{CH3C(OH)(PO3)2}(H2O)2] · 0.5H2O (1) and [NH3CH2CH2NH3][Zn3{CH3C(OH)(PO3)2}2(H2O)] · H2O (2), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. The structure of 1 comprises [Cu3(hedp)2]2− layers connected by [CuO4] units to form a 3D open-framework structure with a one-dimensional channel system along the b axis. In 2, the connections of alternately arranged [ZnO4] tetrahedra, [ZnO6] octahedra and [CPO3] tetrahedra via vertex-sharing result in a 2D layered structure. The protonated ethylenediamine cations and water molecules are located between adjacent layers.

Hydrothermal synthesis and characterization of two new arsenic–vanadate compounds with the same cluster anion [As8V14O42(H2O)]4−

Two new arsenic–vanadate compounds [Co(C4H13N3)2]2[As8V14O42(H2O)] · 3.5H2O (1) and (C2N2H9)2(C2N2H10)[As8V14O42(H2O)] · 2.33H2O (2) have been hydrothermally synthesized and characterized by X-ray single crystal diffraction, IR spectra and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic space group P 2(1)/c, a = 24.649(9) Å, b = 13.364(5) Å, c = 22.463(8) Å, β = 104.008(5)°, V = 7180(5) Å3, Z = 4, R 1 = 0.0787, and wR 2 = 0.1859. Compound 2 crystallizes in rhombohedral system with space group R3c, a = b = c = 22.2405(5) Å, α = β = γ = 110.4030(10)°, V = 8163.4(3) Å3, Z = 6, R 1 = 0.0341 and wR 2 = 0.0941. The structural analyses show that both compounds have the same discrete cluster anion [As8V14O42(H2O)]4−. Moreover, in 1, the polyanions are connected through van der Waals forces to generate soft channels that are filled by [Co(C4H13N3)2]2+ cations and water. In 2, water and organic molecules link cluster anions to create the supramolecular assembly through hydrogen bonding.

Hydrothermal synthesis and crystal structures of Mn(II) and Cd(II) aminophosphonates with a layered structure

Two new divalent metal aminodiphosphonates with a layered structure, Mn2[(HL)(H2O)F]·H2O (1) and Cd3.5[(HL)L] (2) (H4L  = CH3CH2CH2N(CH2PO3H2)2), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. In 1, two MnO4F2 and two MnO5F polyhedra are interconnected via edge-sharing into a tetramer, and such tetramers are bridged by the diphosphonate ligands into a Mn(II) phosphonate layer in the ab-plane. The structure of 2 also features a 2D layered structure, in which the CdO5N and CdO6 polyhedra are interconnected into a 1D chain. The chains are then cross-linked via phosphonate oxygen atoms to form Cd(II) phosphonate layers in the ab-plane.

Synthesis and spectroscopic characterization of organophosphoryl polyoxotungstates α-[PhP(Y)]2X n +W11

Organophosphoryl polyoxotungstate derivatives α-[PhP(Y)]2X n +W11 (X n + = Ge4+, B3+; Y = O, S) have been obtained by the reaction of the monovacant α-[X n +W11O39](12− n )− (X n + = Ge4+, B3+) anions with PhP(O)Cl2 or PhP(S)Cl2 in acetonitrile. These new organic–inorganic hybrid anions have been characterized by elemental analysis, IR, 31P and 183W NMR spectroscopy. According to the elemental analysis and spectroscopic data, the hybrid anions consist of an α-[XW11O39] framework on which are grafted two equivalent PhP(O) or PhP(S) groups through P–O–W bridges. The six-line 183W NMR spectrum indicates that the hybrid anions possess C s symmetry in acetonitrile.

Syntheses, Crystal Structures and Characterization of Two Zeotype Crystals of K4[Cr3O(H2O)3 (OOCH)6]2[P2W18O62] · 9.5H2O and K4[Cr3O(H2O)3(OOCH)6] · [H3P2W17Co(H2O)O61] · 20H2O

Two novel zeotype crystals, K4[Cr3O(H2O)3(OOCH)6]2 [P2W18O62] · 9.5H2O(1) and K4[Cr3O(H2 O)3 · (OOCH)6] [H3P2W17 Co(H2O) O61] · 20H2O (2), were synthesized and their structures were determined using X-ray single crystal diffraction. Crystal data: C12H43O103.5 K4Cr6P2W18(1), hexagonal P6 (3)/m, a = 1.5895 (2) nm, b = 1.5895(2) nm, c = 2.1620 (4) nm, α = 90°, β = 90°, γ = 120°, V = 4.7305 (13) nm3, Z = 2, R1 = 0.0726, wR2 = 0.1542; C6H57O98 K4Cr3CoP2W17 (2), hexagonal P6(3)/mmc, a = 1.61328(3) nm, b = 1.61328(3) nm, c = 2.06613(9) nm, α = 90°, β = 90°, γ = 120°, V = 4.6570(2) nm3, Z = 2, R1 = 0.0377, wR2 = 0.1070. These crystals were characterized using elemental analysis, IR, TG-DTA, and XRD. It was found that the polyoxometalate anions maintained Wells-Dawson structure for crystal 1 and lacunary Wells-Dawson structure for crystal 2. Thermal analysis showed that crystal 1 lost the water of crystallization at 132 °C, whereas crystal 2 lost the water of crystallization at 100 °C. Crystal 1 could reversibly desorb and adsorb water molecules and its crystal structure could be restored after re-adsorbing the water molecules. It was also found from the XRD patterns that the void size of crystal 2 is smaller compared with that of crystal 1, which is attributed to the higher anion charges.