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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

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

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Author(s):
Batista, Nouga C. [1] ; Silva Sa, Jose L. [2] ; McGarvey, Bruce R. [3] ; Franco, Douglas W. [2] ; Lima-Neto, Benedito S. [2]
Total Authors: 5
Affiliation:
[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
Total Affiliations: 3
Document type: Journal article
Source: Reaction Kinetics Mechanisms and Catalysis; v. 102, n. 1, p. 49-65, 2011.
Web of Science Citations: 2
Abstract

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)