Penta-potassium µ-arsenato-bis-(hy-droxy-tetra-molybdate) dihydrate.

The title arsenatomolybdate, K(5)[Mo(8)O(24)(OH)(2)(AsO(4))]·2H(2)O, which was obtained hydro-thermally, features an [AsMo(8)O(28)(OH)(2)](5-) anion, which is formed by two Mo(4)O(14)(OH) units that are linked by As in a sandwich-like fashion. The overall symmetry of the anion is m2m. The {Mo(4)O(14)(OH)} core is composed of two pairs of confacial biocta-hedral {Mo(2)O(9)} units with two µ(4)-O atoms which have been characterized as hydroxyl groups. The anions are further inter-connected by potassium cations, forming a three-dimensional network structure with the uncoordinated water mol-ecules occupying the channels. The structure is further stabilized by O-H⋯O hydrogen bonding.

Preparation and Photocatalytic Application of the Composites PMo12/AgNPs Based on Polyoxometalates.

Supported catalysts, consisting of PMo12 immobilized on silver nanomaterials at different recombination time and the silver nanomaterials with different template sodium citrate amount characterized by FT-IR, XRD, SEM, UV-vis and other test methods. The results show that the AgNPs are relatively uniformed with sizes between 100-300 nm when the sodium citrate addition amount is 9.0 mL. As the reaction time of PMo12/AgNPs increases, the adhesion of AgNPs on the surface of PMo12 becomes more complete. Using PMo12 and PMo12/AgNPs composite materials as catalysts, methylene blue (MB) is photocatalytically degraded under simulated visible light conditions. The results show that PMo12 can catalyze MB effectively, and the decolorization rate reached 98.6% when the catalyst content is 2 g/L, the solution pH is 3 and the MB concentration is 5 mg/L. Under the same experimental conditions, photocatalytic performance of the PMo12/AgNPs system is better than that of the PMo12 further improved the photocatalytic degradation effect of the MB solution with a decolorization rate of 100%. The composite still keeps good photocatalytic activity and stability after three cycles of use. Finally, the catalytic mechanism of the POMs composite material is preliminarily discussed.

Tris(piperazinediium) phosphatododeca-molybo(V,VI)phosphate.

The title compound, (C(4)H(12)N(2))(3)[PMo(12)O(40)] or (H(2)pip)(3)[PMo(12)O(40)] (pip is piperazine), was prepared under hydro-thermal conditions. The asymmetric unit contains one-sixth of a mixed-valent Mo(V,VI) pseudo-Keggin-type [PMo(12)O(40)](6-) anion and half a piperazinediium cation, (H(2)pip)(2+). The discrete Keggin-type [PMo(12)O(40)](6- )anion has site symmetry and the three (H(2)pip)(2+) cations each have site symmetry at the centres of the mol-ecules. The central P atom is on special position , which is a roto-inversion position and generates the disorder of the PO(4) tetra-hedron. Furthermore, six doubly bridging oxide groups are also disordered with an occupancy factor of 0.5 for each O atom. The anions and cations are linked by an extensive network of inter-molecular N-H⋯O and C-H⋯O hydrogen bonds.

Poly[tetra-kis(2,2'-bipyridine)undeca-µ-oxido-hexa-oxidodicopper(II)hexa-vanadium(V)].

In the title organic-inorganic hybrid vanadate complex, [Cu(2)V(6)O(17)(C(10)H(8)N(2))(4)](n), the Cu(II) atom is six-coordinated by two chelating 2,2'-bipyridine (bipy) ligands and two vanadate O atoms in a distorted octa-hedral geometry. Two [Cu(bipy)(2)V(3)O(8)] units are linked by a bridging O atom, which lies on an inversion center, forming a dimeric unit. The dimeric units are further connected by bridging vanadate O atoms into a two-dimensional layer parallel to (100). The layers are connected by weak C-H⋯O hydrogen bonds.

Poly[bis(2,2'-bipyridine-κN,N')heptadeca-µ-oxido-tetraoxidodicopper(II)divanadate(IV)hexavanadate(V)].

In the title complex, [Cu(2)V(8)O(21)(2,2'-bpy)(2)](n) (bpy = bipyridine, C(10)H(8)N(2)), the asymmetric unit contains four independent V atoms briged by 11 O atoms, one of which lies on an inversion center, and a [Cu(2,2'-bpy)](2+) unit. Three V atoms in the polyoxoanion exhibit distorted tetra-hedral coordination geometries while the fourth V atom adopts a trigonal-bipyramidal geometry. The Cu atom adopts a square-pyramidal geometry being coordinated by two nitro-gen donors of a 2,2'-bpy ligand, and three bridging O atoms which are linked with V atoms. The V(8) polyoxoanion is connected to [Cu(2,2'-bpy)](2+) cations, resulting in a two-dimensional layer structure extending parallel to (010). C-H⋯O hydrogen bonding consolidates the structure.

A new hybrid Dawson-type molybdenum arsenate derivative: (H(2)bpy)(3)[As(2)Mo(18)O(62)] (bpy = 4,4'-bipyridine).

The title compound, tris-(4,4'-bipyridinium) diarsenoocta-deca-molybdate(VI), (C(10)H(10)N(2))(3)[As(2)Mo(18)O(62)], featuring protonated bipyridine mol-ecules and a classical Dawson-type polyoxo-anion, has been synthesized under hydro-thermal conditions. The polyoxoanions are linked together via the bipyridyl cations, acting as hydrogen-bond donors, generating a two-dimensional supra-molecular network. The asymmetric unit contains 1.5 4,4'-bipyridinium (H(2)bpy) units, with an inversion centre in the central bond of the second H(2)bpy unit. The site symmetry of the anion is .

Hydrothermal synthesis and structural characterization of the first mixed molybdenum-tungsten capped-keggin polyoxometal complex: {[Co(dien)]4[(AsVO4)MoV8WVI4O33(micro2-OH)3]}.2H2O.

The first polyoxometal complex possessing affirmatory mixed molybdenum-tungsten capped Keggin-type structure has been hydrothermally synthesized.

Hydrothermal syntheses and structural characterizations of organic-inorganic hybrid materials of the M(II)-ligand/vanadium oxide system (M(II) = Mn(II), Cu(II) and Zn(II); ligand = 2,2'-bipyridine and 1,10-phenanthroline).

Three organic-inorganic hybrid compounds [Mn(bpy)V(bpy)V(3)O(11)] (bpy = 2,2'-bipyridine) (1), [Cu(bpy)V(2)O(6)] (2) and [Zn(phen)3][V(2)O(6)].10H(2)O (phen = 1,10-phenanthroline) (3) have been synthesized hydrothermally. Single crystal X-ray diffraction analyses revealed that compound 1 is the first example of bpy units coordinating to different transition metals in one molecule. Compound 2 is a new isomer of [Cu(bpy)V(2)O(6)] which was named the gamma-isomer by us. In compound 3, a 2-D water sheet with big holes filled by the "naked" [V(4)O(12)](4-) clusters is found.

Mutation of Phe50 to Ser50 in the 126/183-kDa proteins of Odontoglossum ringspot virus abolishes virus replication but can be complemented and restored by exact reversion.

Sequence comparison of a non-biologically active full-length cDNA clone of Odontoglossum ringspot virus (ORSV) pOT1 with a biologically active ORSV cDNA clone pOT2 revealed a single nucleotide change of T-->C at position 211. This resulted in the change of Phe50 in OT2 to Ser50 in OT1. It was not the nucleotide but the amino acid change of Phe50 that was responsible for the inability of OT1 to replicate. Time-course experiments showed that no minus-strand RNA synthesis was detected in mutants with a Phe50 substitution. Corresponding mutants in Tobacco mosaic virus (TMV) showed identical results, suggesting that Phe50 may play an important role in replication in all tobamoviruses. Complementation of a full-length mutant OT1 was demonstrated in a co-infected local-lesion host, a systemic host and protoplasts by replication-competent mutants tORSV.GFP or tORSV.GFPm, and further confirmed by co-inoculation using tOT1.GFP+tORSV (TTC), suggesting that ORSV contains no RNA sequence inhibitory to replication in trans. Surprisingly, a small number of exact revertants were detected in plants inoculated with tOT1+tORSV.GFPm or tOT1.GFP+tORSV (TTC). No recombination was detected after screening of silent markers in virus progeny extracted from total RNA or viral RNA from inoculated and upper non-inoculated leaves as well as from transfected protoplasts. Exact reversion from TCT (OT1) to TTT (OT2), rather than recombination, restored its replication function in co-inoculated leaves of Nicotiana benthamiana.