Highly Effective Emulsion ROMP of DCPD and COE Using pH-Responsive Ru-Alkylidene Complexes
Southeastern Regional Meeting of the American Chemical Society (SERMACS)
Ring opening metathesis polymerization (ROMP) has provided access to many new polymeric materials, however, the number of efforts to generate latexes through this technique have been very limited. The few successful polymerizations were also mainly limited to extremely reactive monomers, such as norbornene. Less reactive ROMP monomers such as dicyclopentatdiene (DCPD) or cyclooctene (COE) failed to generate high conversions in emulsion-ROMP in previous attempts. We have developed a series of Ru-alkylidene complexes bearing pH-responsive N-heterocyclic carbene (NHC) ligands in addition to basic N-donor ligands. While our complexes displayed rather unremarkable metathesis activity under standard ROMP conditions, they could be activated and rendered water-soluble via acidic addition. In the presence of aqueous HCl, the catalysts accomplish near quantitative conversions of DCPD and COE in micro-emulsion with acidic aqueous media using catalyst loadings as low as 200 ppm and in reaction times as low as 30 min, while forming stable latexes.
"Highly Effective Emulsion ROMP of DCPD and COE Using pH-Responsive Ru-Alkylidene Complexes."
Southeastern Regional Meeting of the American Chemical Society (SERMACS) Atlanta, GA: American Chemical Society.