Two novel inorganic–organic hybrids based on saturated Wells–Dawson polyoxoanion and copper–organonitrogen coordination polymer

Crystal structure of hexa-kis-(di-methyl-formamide-κO)manganese(II) deca-kis-(di-methyl-formamide)-1κ(5) O,2κ(5) O-[μ-octa-deca-tungstodiphosphato(V)-κO:κO']dimanganate(II) di-methyl-formamide disolvate

The crystal structure of the title compound, [Mn(C3H7NO)6][{Mn(C3H7NO)5}2(μ-P2W18O62)]·2C3H7NO, reveals that the Wells-Dawson-type polyanion [P2W18O62](6-), through terminal O atoms from the belts, bridges two Mn(II) octa-hedral complexes. In the complex anion [{Mn(dmf)5}2(μ-P2W18O62)](2-), located around a twofold rotation axis, the Mn(II) ions are coordinated by five O atoms from di-methyl-formamide (dmf) ligands and to a terminal O atom from the [P2W18O62](6-) polyanion. Another Mn(II) ion, located on an inversion centre, is coordinated by six O atoms from the dmf ligands and forms the [Mn(dmf)6](2+) cation. The crystal components are connected through numerous weak C-H⋯O hydrogen bonds to construct a three-dimensional network.

Combination of lacunary polyoxometalates and high-nuclear transition metal clusters under hydrothermal conditions: IX. a series of novel polyoxotungstates sandwiched by octa-copper clusters

The reaction of CuCl(2).2 H2O with trivacant Keggin polyoxoanions K8Na2[A-alpha-GeW9O34].25 H2O or K10[A-alpha-SiW9O34].25 H2O in the presence of 1,2-diaminopropane (dap), ethylenediamine (en) or 2,2'-bipyridine (2,2'-bpy) under hydrothermal conditions afforded five novel hybrid inorganic-organic octa-Cu sandwiched polyoxotungstates (POTs): H4[CuII8(dap)4(H2O)2(B-alpha-GeW9O34)2].13 H2O (1), (H2en)2[CuII8-(en)4(H2O)2(B-alpha-GeW9O34)2].5 H2O(2), (H2en)2[CuII8(en)4(H2O)2(B-alpha-SiW9-O34)2].8 H2O (3), [CuII(H2O)2]H2[CuII8-(en)4(H2O)2(B-alpha-SiW9O34)2] (4), and [CuII2(H2O)2(2,2'-bpy)2]{[CuII(bdyl)]2-[CuII8(2,2'-bpy)4(H2O)2(B-alpha-GeW9-O34)2]}.4 H2O (bdyl=2,2'-bipyridinyl)(5). Additionally, CuCl(2).2 H2O reacts with the mixture of GeO2, Na2WO(4).2 H2O, H2SiW12O(40).2 H2O in the presence of 2,2'-bpy and 4,4'-bpy under hydrothermal conditions leading to another novel mixed-valent octa-Cu sandwiched POT hybrid: [CuI(2,2'-bpy)(4,4'-bpy)]2[{CuI2(2,2'-bpy)2(4,4'-bpy)]2[CuI2CuII6(2,2'-bpy)2(4,4'-bpy)2(B-alpha-GeW9O34)2}].2 H2O (6). 1, 2, and 3 are discrete dimers constructed from two trivacant Keggin [B-alpha-XW9O34]10- (X=GeIV/SiIV) fragments and an octa-Cu cluster whereas 4 displays the 3D (3,6)-connected nets with (4.6(2))(4(2).6(4).8(7).10(2)) topology, which are built by octa-Cu sandwiched polyoxometalate building blocks through copper cation bridges. 5 is a novel 2D layer based on octa-Cu sandwiched POT clusters and [CuII2(bdyl)] units. Interestingly, the rollover metalation of 2,2'-bpy is firstly observed in the system containing the copper complex under hydrothermal conditions. 6 is a discrete mixed-valent octa-Cu sandwiched POT supported by two CuI-complexes [CuI2-(2,2'-bpy)2(4,4'-bpy)]2+ through 4,4'-bpy bridges, which constructs a novel dodeca-copper cluster. Notably, the octa-Cu cluster in 6 is mixed-valent and is different from those in 1-5. To our knowledge, 1-6 represent a rare family of POTs incorporating novel octa-nuclear transition-metal clusters in polyoxometalate chemistry. They were structurally characterized by FT-IR spectra, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. The magnetic properties of 1, 4, and 5 were quantitatively analyzed by the MAGPACK software package.

Hydrothermal synthesis, crystal structure and electrochemical properties of a novel 3D Dawson-type polyoxometalate supramolecular network

A novel Dawson-type polyoxometalate supramolecular architecture of the formula [4,4′-H2bipy]2.5·[4,4′-Hbipy]·[P2W18O62]·6.25H2O (4,4′-bipy = 4,4′-bipyridine) has been hydrothermally synthesised and characterised by means of elemental analysis, IR, CV and X-ray single-crystal diffraction. X-ray crystallography indicates that the title compound consists of Dawson-type polyoxoaions [P2W18O62]6-, water molecules and 4,4′-bipy units. The polyoxoanion clusters together with 4,4′-bipy units and water molecules to construct the three-dimensional supramolecular network through hydrogen bonds. The crystal structure analyses reveal that water molecules and 4,4′-bipy units play the important role on the packing arrangements of crystals. Cyclic voltammetry shows that the title compound exhibits three chemically reversible steps