Synthesis, Structure, and Catalytic Performance in Cyclooctene Epoxidation of a Molybdenum Oxide/Bipyridine Hybrid Material: {[MoO3(bipy)][MoO3(H2O)]}n

• Tipo: Artigo em Revista Científica Internacional
• Data: 2010

Autores

Abrantes, M (Autor) Outra; Amarante, TR (Autor) Outra; Antunes, MM (Autor) Outra; Gago, S (Autor) Outra; Almeida Paz, FAA (Autor) Outra; Margiolaki, I (Autor) Outra; Alírio Rodrigues (Autor) FEUP; Pillinger, M (Autor) Outra; Valente, AA (Autor) Outra; Goncalves, IS (Autor) Outra

Revista

Título: Inorganic Chemistry

Vol. 49 Nº 15

Páginas: 6865-6873

ISSN: 0020-1669

Editora: American Chemical Society

Indexação

ISI Web of Knowledge - 32 Citações

Scopus - 27 Citações

Outras Informações

ID Authenticus: P-003-42D

DOI: 10.1021/ic100479a

Abstract (EN): The reaction of [MoO2Cl2(bipy)] (1) (bipy = 2,2'-bipyridine) with water in a Teflon-lined stainless steel autoclave (100 degrees C, 19 h), in an open reflux system with oil bath heating (12 h) or in a microwave synthesis system (120 degrees C, 4 h), gave the molybdenum oxide/bipyridine hybrid material {[MoO3(bipy)][MoO3(H2O)]}(n) (2) as a microcrystalline powder in yields of 72-92%. The crystal structure of 2 determined from synchrotron X-ray powder diffraction data is composed of two distinct neutral one-dimensional polymers: an organic-inorganic polymer, [MoO3(bipy)](n), and a purely inorganic chain, [MoO3(H2O)](n), which are interconnected by O-H center dot center dot center dot O hydrogen bonding interactions. Compound 2 is a moderately active, stable, and selective catalyst for the epoxidation of cis-cyclooctene at 55 degrees C with tert-butylhydroperoxide (tBuOOH, 5.5 M in decane or 70% aqueous) as the oxidant. Biphasic solid-liquid or triphasic solid-organic-aqueous mixtures are formed, and 1,2-epoxycyclooctane is the only reaction product. When n-hexane is employed as a cosolvent and tBuOOH(decane) is the oxidant, the catalytic reaction is heterogeneous in nature, and the solid catalyst can be recycled and reused without a loss of activity. For comparison, the catalytic performance of the precursor 1 was also investigated. The IR spectra of solids recovered after catalysis indicate that 1 transforms into the organic-inorganic polymer [MoO3(bipy)] when the oxidant is tBuOOH(decane) and compound 2 when the oxidant is 70% aqueous tBuOOH.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 9