A latent S-chelated ruthenium benzylidene initiator for ring-opening metathesis polymerization

The results on the use of sulfur-chelated ruthenium olefin metathesis initiators in ring-opening methathesis polymerization (ROMP) reactions were presented. All chemicals were of reagent grade quality, purchased commercially from Sigma, Aldrich, Fluka, and ABCR and used without further purification. The results show that the monomer polymerization occur when the reaction vessel is heated and after initial activation by heating no further monomer consumption is observed. The reaction is found to realize at -20°C and prevent detrimental chain transfer and maintain monomodal low polydispersity. It is found that polymer sizes fluctuate around the 10⁶ g/mol mark independent of catalyst loading, while polydispersities invariably remained between 1.2 and 1.45. While probing high monomer to initiator ratios, only trimodal chromatograms are observed indicating chain transfer processes.