An insight into the beginning stage of the aqueous ring opening metathesis polymerization of exo,exo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid with Ru-III compounds: the consumption of Ru-III species in the presence of carboxylic acids monitored by ESR spectroscopy

Autor(es)

Batista, Nouga C. ^[1] ; Silva Sa, Jose L. ^[2] ; McGarvey, Bruce R. ^[3] ; Franco, Douglas W. ^[2] ; Lima-Neto, Benedito S. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Estadual Piaui, Ctr Ciencias Nat, BR-64002150 Teresina, PI - Brazil

^[2] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560980 Sao Carlos, SP - Brazil

^[3] Univ Windsor, Dept Chem & Biochem, Windsor, ON N9B 3P4 - Canada

• Tipo de documento: Artigo Científico
• Fonte: Reaction Kinetics Mechanisms and Catalysis; v. 102, n. 1, p. 49-65, 2011.
• Citações Web of Science: 2

Resumo

The presence of paramagnetic species in the aqueous ring opening metathesis polymerizations of the exo,exo-7-oxabicyclo{[}2.2.1]hept-5-ene-2,3-dicarboxylic acid monomer with RuCl(3) and K(2){[}RuCl(5)H(2)O] compounds was studied using ESR techniques. It was observed that the intensities of the Ru(III) signals in the ESR spectra decrease on the time scale of the induction period so that the ROMP can take place. The intensity of the Ru(III) signal almost disappeared 50 min after reacting with K(2){[}RuCl(5)H(2)O] and after 100 mm in the case of RuCl(3). Reactions of the cis-{[}Ru(NH(3))(4)(H(2)O)(2)](tfms)(3) and {[}Ru(NH(3))(5)H(2)O](tfms)(3) complexes with the monomer and different organic compounds representing the organic functions in the monomer (furan, norbornene, but-2-ene-1,4-diol and formic, acetic, oxalic and maleic acids) were also monitored by ESR and UV/vis spectra. It was deduced that the organic acids provide the disappearance of the Ru(III) signal. The proton NMR relaxation times of the residual water in D(2)O for reactions with oxalic acid suggested that the presence of paramagnetic ions in the solution decreases along with (AU)

• Processo FAPESP: 06/57577-4 - Uso de combinações de ligantes ancilares de P(III), N(III), e S(II ou IV) no desenvolvimento de catalisadores de Ru(II) para polimerização via metátese de olefinas
• Beneficiário: Benedito dos Santos Lima Neto
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 00/11443-0 - Desenvolvimento de sistemas catalíticos para reações de polimerização via metátese de olefinas cíclicas, tendo compostos de rutênio como material de partida
• Beneficiário: Benedito dos Santos Lima Neto
• Modalidade de apoio: Auxílio à Pesquisa - Regular