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 RuIII compounds: the consumption of RuIII species in the presence of carboxylic acids monitored by ESR spectroscopy

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 min 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 Electronic supplementary material The online version of this article (

Copolymers from norbornene and norbornadiene with organized morphologies and high Tg values obtained via ROMP with a highly reactive [RuCl3(PCy3)2] complex

“…In the past, we investigated ROMP with RuCl 3 and concluded that a Ru II species was generated in situ, thus reaching a low spin d 6 electronic configuration to activate the olefin in the reaction. 33,34 However, the reactions could not occur so fast where coordination of ligands and a redox reaction must occur before the induction period. In the current case, the reactions occurred very fast.…”