resumo
The organotin vanadate [Me3SnVO3] (1) has been prepared and characterised in the solid state by powder X-ray diffraction (XRD), thermogravimetric analysis, multinuclear magic-angle spinning (MAS) NMR, IR and Raman spectroscopy. The phase purity and structure of microcrystalline 1 were confirmed by carrying out a full Rietveld structural refinement at ambient temperature and from conventional powder XRD. V-51 and Sn-119 MAS NMR data for compound 1 were in agreement with the predicted structure, showing two equally-abundant, nonequivalent Me3Sn groups and two equally-abundant, nonequivalent vanadium atoms. The compound was applied as a catalyst for the liquid-phase epoxidation of olefins at 55 degrees C using tert-butyl hydroperoxide (tBuOOH) as the oxidant. The reaction rate for the different substrates followed the order cis-cyclooctene > (R)-(+)-limonene congruent to trans-2-octene > cyclododecene > styrene > 1-octene; the corresponding epoxides were the only observed products. Leaching tests indicated that the catalytic epoxidation of cyclooctene was mainly heterogeneous in nature.
palavras-chave
MULTINUCLEAR MAGNETIC-RESONANCE; BOND-VALENCE PARAMETERS; CRYSTAL-STRUCTURE; ZEOLITE-LIKE; 3-DIMENSIONAL POLYMERS; STRUCTURE DIRECTORS; DICHOTOMY METHOD; METAL CYANIDES; ORGANOTIN; DIFFRACTION
categoria
Polymer Science
autores
Abrantes, M; Balula, MS; Valente, AA; Paz, FAA; Pillinger, M; Romao, CC; Rocha, J; Goncalves, IS
nossos autores
Anabela Tavares Aguiar Valente
Investigador Principal
Filipe Alexandre Almeida Paz
Investigador Principal
Isabel Maria de Sousa Gonçalves
Professor associado
João Rocha
Prof. Catedrático