نتایج جستجو برای: α keggin

تعداد نتایج: 165395  

Journal: :Dalton transactions 2012
John Fielden Kyle Quasdorf Leroy Cronin Paul Kögerler

An unusual PFO(3)(2-)-templated "inverse Keggin" polyanion, [Mo(12)O(46)(PF)(4)](4-), has been isolated from the degradation reaction of an {Mo(132)}-type Keplerate to [PMo(12)O(40)](3-) by [Cu(MeCN)(4)](PF(6)) in acetonitrile. (31)P-NMR studies suggest a structure-directing role for [Cu(MeCN)(4)](+) in the formation of the highly unusual all-inorganic inverse Keggin structure.

Journal: :Angewandte Chemie 2003
Haichao Liu Nader Bayat Enrique Iglesia

Catalytic reactions often require several types of sites with distinct functions, and the relative abundance of these sites influences the rate and selectivity of desired reactions. Heteropolyacid clusters with Keggin structures, which contain acid and redox functions, 2] have recently emerged as interesting catalysts for organic reactions involving bifunctional pathways. We recently discovered...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2009
Holger Wille Maheswaran Shanmugam Muralee Murugesu Julian Ollesch Gerald Stubbs Jeffrey R Long Jiri G Safar Stanley B Prusiner

Prions are composed solely of an alternatively folded isoform of the prion protein (PrP), designated PrP(Sc). N-terminally truncated PrP(Sc), denoted PrP 27-30, retains infectivity and polymerizes into rods with the ultrastructural and tinctorial properties of amyloid. We report here that some polyoxometalates (POMs) favor polymerization of PrP 27-30 into prion rods, whereas other POMs promote ...

2008
Mei Lin Wei Rui Ping Sun Kai Jiang

A porous coordination polymer, {[Eu(dpdo)4(H2O)3]H(SiMo12O40)(dpdo)0.5(CH3CN)0.5(H2O)4}n (1), (where dpdo is 4,4′-bipyridine-N,N′-dioxide) templated by double-Keggin-type polyanions has been synthesized through the self-assembly of Eu(III) ions and dpdo in acetonitrile/water solution and structurally characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The X-ray...

Journal: :Dalton transactions 2015
M Dave C Streb

A comparative study investigating the effects of metal substitution on the photocatalytic activity of metal oxide cluster anions is presented. The study shows that metal functionalization can be used to alter the photochemical properties of monolacunary tungstate - based Keggin clusters (α-[TM(H2O)SiW11O39](n-) (M = Co(2+), Cu(2+), Ni(2+), Mn(2+))). It is demonstrated that the photoactivity for...

2011
Babak Feizyzadeh Masoud Mirzaei Hossein Eshtiagh-Hosseini Ahmad Gholizadeh

The title heteropolyoxidotungstate-based inorganic-organic hybrid material, (C(6)H(12)N(5)O)(3)[W(12)(PO(4))O(36)]·6H(2)O, consists of one α-Keggin-type [W(12)(PO(4))O(36)](3-) polyoxidometalate anion (POM), three crystallographically independent 4-[(2H-tetra-zol-5-yl)meth-yl]morpholinium cations and six water mol-ecules of crystallization. The morpholine ring of the cation adopts a chair confo...

Journal: :Chemical communications 2011
Yunxia Jiang Shuxia Liu Shujun Li Jun Miao Jing Zhang Lixin Wu

Non-mesogenic unit bearing Keggin-type polyoxoanions with tetra-n-octylammonium counterions exhibit an ionic liquid crystalline structure via ionic self-assembly in a certain temperature range.

2016
Jun-Wei Zhao Hai-Lou Li Xing Ma Zhigang Xie Li-Juan Chen Yongsheng Zhu

By virtue of the stereochemical effect of the lone-electron pair located on the trigonal-pyramidal-AsO3 groups and the one-pot self-assembly strategy in the conventional aqueous solution, a series of novel lanthanide-bridging and lone-electron-pair active trigonal-pyramidal-AsO3 inducing nanosized poly(polyoxotungstate) aggregates [H2N(CH3)2]6 Na24H16{[Ln10W16(H2O)30O50](B-α-AsW9O33)8}·97H2O [L...

2010
Lujiang Hao Chunling Ma Jianghui Chen Xiaofei Zhang Xiutang Zhang

The asymmetric unit of the title compound, [Mn(C(8)H(7)N(3))(3)](2)[PMo(12)O(40)]·6H(2)O, consists of a complex [Mn(C(8)H(7)N(3))(3)](2+) cation, half of a mixed-valent Mo(V,VI) α-Keggin-type [PMo(12)O(40)](4-) heteropolyanion, and three uncoordinated water mol-ecules. The Mn(2+) cation is surrounded by six N atoms from three chelating 3-(2-pyrid-yl)-1H-pyrazole ligands in a distorted octa-hedr...

Journal: :Dalton transactions 2006
Masahiro Sadakane Daisuke Tsukuma Michael H Dickman Bassem Bassil Ulrich Kortz Michio Higashijima Wataru Ueda

We have synthesized the mono-ruthenium substituted Keggin-type silicotungstate [SiW(11)O(39)Ru(III)(H(2)O)](5-) (1a) by reaction of the mono-lacunary silicotungstate precursor [SiW(11)O(39)](8-) with Ru(acac)(3) under hydrothermal conditions and isolated as the caesium salt Cs(5)[SiW(11)O(39)Ru(III)(H(2)O)] (1). The DMSO-coordinated complex [SiW(11)O(39)Ru(III)(DMSO)](5-) (2a) was prepared by r...

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