Molecular Weight Control via Cross Metathesis in Photo-Redox Mediated Ring-Opening Metathesis Polymerization

Victoria K Kensy; Rachel L Tritt; Farihah M Haque; Laura M Murphy; Daniel B Knorr Jr; Scott M Grayson; Andrew J Boydston

doi:10.1002/anie.202000434

Molecular Weight Control via Cross Metathesis in Photo-Redox Mediated Ring-Opening Metathesis Polymerization

Angew Chem Int Ed Engl. 2020 Jun 2;59(23):9074-9079. doi: 10.1002/anie.202000434. Epub 2020 Mar 24.

Authors

Victoria K Kensy¹, Rachel L Tritt², Farihah M Haque³, Laura M Murphy¹, Daniel B Knorr Jr⁴, Scott M Grayson³, Andrew J Boydston^{2

1}

Affiliations

¹ University of Washington, Seattle, WA, 98195, USA.
² University of Wisconsin-Madison, Madison, WI, 53706, USA.
³ Tulane University, New Orleans, LA, 70118, USA.
⁴ U. S. Army Research Laboratory, Aberdeen Proving Ground, MD, 21005, USA.

PMID: 32059058
DOI: 10.1002/anie.202000434

Abstract

Photo-redox mediated ring-opening metathesis polymerization (photo-ROMP) is an emerging ROMP technique that uses an organic redox mediator and a vinyl ether initiator, in contrast to metal-based initiators traditionally used in ROMP. The reversibility of the redox-mediated initiation and propagation steps enable spatiotemporal control over the polymerization. Herein, we explore a simple, inexpensive means of controlling molecular weight, using alpha olefins as chain transfer agents. This method enables access to low molecular weight oligomers, and molecular weights between 1 and 30 kDa can be targeted simply by altering the stoichiometry of the reaction. This method of molecular weight control was then used to synthesize a functionalized norbornene copolymer in a range of molecular weights for specific materials applications.

Keywords: ROMP; chain transfer; cross metathesis; functional polymers; photoredox catalysis.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.