About the Seminar:

Organocatalyzed atom transfer radical polymerization (O-ATRP) is a controlled radical polymerization method that uses organic photoredox catalysts (PCs) and visible light to produce polymers with well-defined structures. Diaryl dihydrophenazine PCs have mediated controlled polymerizations as indicated by low dispersity (Ð < 1.3), but in previous work low initiator efficiency (I* < 100%) has indicated lack of ability to achieve targeted molecular weights. The observed low I* has been attributed to a side reaction between the PC core and alkyl radicals during polymerization. In this work, core substitution of the catalyst is used as a route to minimize side reactivity and to tune PC structure, properties, and performance in O-ATRP. Exploration of alkyl, aryl, and heteroatom core substitution reveals new structure-property relationships that are leveraged to improve polymerization outcomes and address current limitations of O-ATRP.