resumo
The compounds MoO2Cl2L (L = 2,2'-bipyridine (bipy) (1); 4,4'-di-tert-butyl-2,2'-bipyridine (di-Bu-t-bipy) (2)), [MoO2Cl2(H2O)(2)]center dot(diglyme)(2) (3), MoO2Cl2 (4), MoO2(CH3)(2)L (L bipy (5); di-Bu-t-bipy (6)), [MoO3(bipy)] n (7), {[MoO3(bipy)][MoO3(H2O)]} n (8), [Mo8O22(OH)(4)(di-Bu-t-bipy)(4)] (9) and MoO3 (10) were tested as phosphoester bond hydrolysis promoters in aqueous media. Sodium para-nitrophenylphosphate (pNPP) was used as a model substrate for the phosphoester bond hydrolysis reaction, which was performed at 55 degrees C, using D2O as solvent and 100 or 10 mol% of the chosen promoter. The progression of all the reactions was monitored by H-1 NMR spectroscopy. All studied systems promote phosphoester bond hydrolysis. The best performance was obtained with MoO2Cl2L compounds (1-4) and with the inorganiceorganic hybrid {[MoO3(bipy)][MoO3(H2O)]}(n) (8). The studied compounds originate either homogeneous or solid/liquid biphasic systems. For the biphasic systems (1, 2, 5-9), the solid phase was recovered at the end of the reaction and characterized by FT-IR spectroscopy. (C) 2014 Elsevier B. V. All rights reserved.
palavras-chave
CYCLOOCTENE EPOXIDATION; ORGANOMETALLIC COMPLEX; CATALYTIC APPLICATIONS; BOND-CLEAVAGE; MOLYBDATE; POLYOXOMOLYBDATE; PERFORMANCE; PRECURSORS; PHOSPHATE; OLEFINS
categoria
Chemistry
autores
Gomes, AC; Pillinger, M; Nunes, P; Goncalves, IS; Abrantes, M
nossos autores
Ana Catarina Costa Gomes Alves
Investigador Auxiliar
Isabel Maria de Sousa Gonçalves
Professor associado
Martyn Pillinger
Investigador PrincipalProjectos
Use of molecular containers to modify metallocene-based catalysts (PTDC/QEQ-SUP/1906/2012)
agradecimentos
We are grateful to the Fundacao para a Ciencia e a Tecnologia (FCT, Portugal), the Programa Operacional Ciencia e Inovacao (POCI) 2010, Orcamento do Estado (OE), European Union, Fundo Europeu de Desenvolvimento Regional (FEDER), QREN, COMPETE, the Associate Laboratory CICECO (PEst-C/CTM/LA0011/2013), and CQE (PEst-OE/QUI/UI0100/2013) for continued support and funding, including the R&D Project PTDC/QEQ-SUP/1906/2012 and the research grant BPD/UI89/4864/2013 provided within this project. The authors also thank the Portuguese NMR Network (IST-UTL Center) (RECI/QEQ-QIN/0189/2012) for providing access to the NMR facilities.