Abstract

The synthesis, characterization, reactivity, and selectivity of six novel ruthenium metathesis catalysts containing oxyanions as ligands are described. A drop in chemoselectivity and/or reactivity in alternating ring-opening metathesis polymerization of norbornene and cyclooctene for catalysts with nitrate, acetate, and benzoate ligands (i.e., catalysts 7, 8, and 10a) compared to the parent complex bearing chloride as a ligand (5b) is observed, while catalysts with trifluoroacetate, methylbenzoate, and triisopropylbenzoate ligands (i.e., catalysts 9, 10b, and 10c) exhibit the expected activities and chemoselectivities. A model accounting for the aforementioned observations is based on a chelating effect of oxyanion ligands in these complexes and is supported by NMR data, crystal structures of the new complexes, and DFT calculations. Through comparison of selectivity and reactivity in copolymerizations with NMR and X-ray structures, we have uncovered correlations that serve as predictive tools for catalyst design.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.