Organocatalysts for Radical Polymerization

This chapter delves into organocatalysts for radical polymerizations, with a primary focus on the guidelines of designing organocatalysts in photocontrolled reversible deactivation radical polymerization (photo-RDRP), such as organocatalyzed atom transfer radical polymerization (O-ATRP) and the organocatalyzed photoinduced electron/energy transfer reversible addition-fragmentation chain transfer polymerization (PET-RAFT). The huge number of organocatalysts that emerged in the last 15 years are first categorized based on the chromophore core classification, for both O-ATRP and PET-RAFT, respectively. Their design guidelines, termed as structure–property-performance (SPP) relationships, are explored theoretically so as to establish the intrinsic relationships from the electronic structure to actual polymerization performances. In order to gain understanding at the theoretical level, mechanistic evaluation of the photon absorption, excited-state evolution, activation, and deactivation steps, emphasizing on oxidative quenching pathway (OQP), is performed to extract the key properties and performance aspects in photo-RDRP; from which the respective SPP relationships are reviewed.