resumo
The dissolution of the indenyl (Ind) complex [{(eta(5)-Ind)Mo(CO)(2)(mu-Cl)}(2)] (1) in N,N'-dimethylformamide (DMF) gives the ring-slipped complex [(eta(3)-Ind)Mo(CO)(2)Cl(DMF)(2)] (2). The aerial oxidation of 2 leads to the formation of the dinuclear oxomolybdenum(V) chloride [Mo2O2(DMF)(4)(mu-O)(2)Cl-2] (3). The structures of 2 and 3 DMF have been determined by single-crystal X-ray diffraction. Compounds 1 and 3 were examined as promoters of phosphoester bond hydrolysis in para-nitrophenylphosphate (pNPP), which was used as a model substrate. The reactions were performed in aqueous solution at 55 degrees C and followed by H-1 NMR spectroscopy. For assays performed with 30-100 mol-% of 1 or 3 relative to pNPP, both compounds promote the production of para-nitrophenol (pNPh) from pNPP. Compound 3 is especially active in promoting the hydrolytic cleavage of the phosphoester bond (t(1/2) < 80 min).
palavras-chave
ALPHA-PINENE OXIDE; ORGANOMETALLIC COMPLEX; MICELLAR-SOLUTION; INDENYL ANALOGS; RING SLIPPAGE; MIXED-RING; MOLYBDENUM; DERIVATIVES; CLEAVAGE; CATALYST
categoria
Chemistry
autores
Gomes, AC; Gamelas, CA; Fernandes, JA; Paz, FAA; Nunes, P; Pillinger, M; Goncalves, IS; Romao, CC; Abrantes, M
nossos autores
Ana Catarina Costa Gomes Alves
Investigador Auxiliar
Filipe Alexandre Almeida Paz
Investigador Principal
Isabel Maria de Sousa Gonçalves
Professor associado
José Alberto Pires Fernandes
Bolseiro de pós-Doutoramento
Martyn Pillinger
Investigador PrincipalProjectos
Use of molecular containers to modify metallocene-based catalysts (PTDC/QEQ-SUP/1906/2012)
PTNMR - Portuguese Nuclear Magnetic Resonance Network (REDE/1517/RMN/2005)
agradecimentos
This work was partly financed by FEDER (Fundo Europeu de Desenvolvimento Regional) through COMPETE (Programa Operacional Factores de Competitividade) and by national funds through the FCT (Fundacao para a Ciencia e a Tecnologia) with the projects CICECO (Centre for Research in Ceramics and Composite Materials) - FCOMP-01-0124-FEDER-037271 (FCT ref. PEst-C/CTM/LA0011/2013), FCOMP-01-0124-FEDER-029779 (FCT ref. PTDC/QEQ-SUP/1906/2012, including the research grant with ref. BPD/UI89/4864/2013 to A. C. G.) - and the Centro de Quimica Estrutural (PEst-OE/QUI/UI0100/2013). We further wish to thank the FCT for specific funding towards the purchase of the single-crystal diffractometer and for the postdoctoral grant SFRH/BPD/63736/2009 (to J. A. F.). The authors are grateful to M. C. Oliveira for the ESI-MS analysis. The NMR spectrometers are part of The National NMR Network (REDE/1517/RMN/2005), supported by POCI 2010 (Programa Operacional Ciencia e Inovacao 2010) and the FCT. The authors also thank the Portuguese NMR Network (Instituto Superior Tecnico Center) (RECI/QEQ-QIN/0189/2012) for providing access to the NMR facilities.