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1.
Dalton Trans ; 45(37): 14544-8, 2016 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-27472151

RESUMO

Fluorophilic polyoxotungstates perform the selective epoxidations of internal and terminal double bonds by hydrogen peroxide (H2O2) activation in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), under mild temperature conditions. A hybrid synergy of supramolecular interactions, involving the inorganic cluster and the fluorinated solvent, is envisaged to boost H2O2 activation and the oxygen transfer mechanism. 1,2-Epoxides have been obtained with >99% selectivity and 98% yield at T = 40-70 °C.

2.
Chemistry ; 18(41): 13195-202, 2012 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-22927018

RESUMO

Anchoring terminal octenyl tails on molecular polyoxotungstates yield polymerizable organic-inorganic monomers with formula [{CH(2)=CH(CH(2))(6)Si}(x)O(y)SiW(w)O(z)](4-) [x = 2, w = 11, y = 1, z = 39 (1); x = 2, w = 10, y = 1, z = 36 (2); and x = 4, w = 9, y = 3, z = 34 (3)]. These molecular hybrids can use aqueous hydrogen peroxide to catalyze the selective oxidation of organic sulfides in CH(3)CN. Copolymerization of 1-3 with methyl methacrylate and ethylene glycol dimethacrylate leads to porous materials with a homogeneous distribution of the functional monomers, as indicated by converging evidence from FTIR spectroscopy and electronic microscopy. The catalytic polymers activate hydrogen peroxide for oxygen transfer, as demonstrated by the quantitative and selective oxidation of methyl p-tolyl sulfide, which was screened as model substrate. The hybrid material containing monomer 2 was also tested in n-octane to evaluate its potential for the oxidation and removal of dibenzothiophene, a well-known gasoline contaminant.

3.
Chem Commun (Camb) ; 47(6): 1716-8, 2011 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-21221441

RESUMO

The oxygen evolving catalyst [Ru(4)(µ-OH)(2)(µ-O)(4)(H(2)O)(4)(γ-SiW(10)O(36))(2)](10-) effects H(2)O(2) dismutation at rates (k = 36.8 ± 1.4 M(-1) s(-1)), one/two order of magnitude higher compared to related tetra-substituted Cu, Fe, Mn, Ni and even Co polyoxometalates, thus providing localised oxygen gas bursts to power nano-propulsion of composite materials.


Assuntos
Peróxido de Hidrogênio/química , Oxigênio/química , Compostos de Tungstênio/química , Soluções Tampão , Catalase/química , Catalase/metabolismo , Catálise , Concentração de Íons de Hidrogênio , Cinética , Metais/química , Oxigênio/metabolismo , Soluções/química , Espectrofotometria Infravermelho , Análise Espectral Raman , Termogravimetria , Compostos de Tungstênio/metabolismo , Água/química
4.
Chem Commun (Camb) ; (43): 4533-5, 2006 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-17283809

RESUMO

Hybrid fluoropolymeric membranes with 25% loading of the fluorous-tagged (RfN)4W10O32 effect the solvent-free photooxygenation of benzylic C-H bonds with up to 6100 TONs in 4 hours.

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