End-Functionalized Palladium SCS Pincer Polymers via Controlled Radical Polymerizations

A direct and facile route toward semitelechelic polymers, end-functionalized with palladated sulfur–carbon–sulfur pincer (PdII-pincer) complexes is reported that avoids any post-polymerization step. Key to our methodology is the combination of reversible addition-fragmentation chain-transfer (RAFT) polymerization with functionalized chain-transfer agents. This strategy yields Pd end-group-functionalized materials with monomodal molar mass dispersities (Đ) of 1.18–1.44. The RAFT polymerization is investigated using a PdII-pincer chain-transfer agent for three classes of monomers: styrene, tert-butyl acrylate, and N-isopropylacrylamide. The ensuing PdII-pincer end-functionalized polymers are analyzed using 1H NMR spectroscopy, gel-permeation chromatography, and elemental analysis. The RAFT polymerization methodology provides a direct pathway for the fabrication of PdII-pincer functionalized polymers with complete end-group functionalization.