10.1021/ma101893u.s001 Till Gruendling Till Gruendling Michael Kaupp Michael Kaupp James P. Blinco James P. Blinco Christopher Barner-Kowollik Christopher Barner-Kowollik Photoinduced Conjugation of Dithioester- and Trithiocarbonate-Functional RAFT Polymers with Alkenes American Chemical Society 2011 UV radiation aliphatic alkene Photoinduced Conjugation benzyl dithioacetic acid ester ambient temperature 1 H NMR 7 h reaction mechanism thiocarbonyl poly SEC 1 h dodecyl trithiocarbonate polymer photoinduced conjugation CPDA absorption wavelength acrylate AlkenesWe report 2011-01-11 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Photoinduced_Conjugation_of_Dithioester_and_Trithiocarbonate_Functional_RAFT_Polymers_with_Alkenes/2699488 We report the photoinduced conjugation of polymers synthesized via reversible addition−fragmentation chain transfer (RAFT) polymerization with a number of low molecular weight (functional) olefins. Upon irradiation of a solution of an aliphatic alkene and the benzyl dithioacetic acid ester (CPDA) or dodecyl trithiocarbonate (DoPAT) functional poly(alkyl acrylate) at the absorption wavelength of the thiocarbonyl group (315 nm), incorporation of the alkene at the polymer chain-end occurred. The most efficient systems identified with regard to the rate of reaction and yield were poly(butyl acrylate)/CPDA/ethyl vinyl ether (78% monoinsertion product after 1 h) and poly(butyl acrylate)/CPDA/1-pentene (73% insertion product after 7 h) at ambient temperature. An in-depth analysis of the reaction mechanism by <sup>1</sup>H NMR and online size-exclusion chromatography-electrospray ionization tandem mass spectrometry (SEC/ESI−MS<sup>n</sup>) revealed that a possible [2 + 2] photoaddition mechanism of conjugation does not take place. Instead, fast β-cleavage of the photoexcited RAFT-end group with subsequent radical addition of an alkene was observed for all employed systems. The presented reaction thus provides a means of spatial and temporal control for the conjugation of alkenes to thiocarbonyl thio-capped macromolecules via the use of UV radiation.