title: Selective Photoactivation: From a Single Unit Monomer Insertion Reaction to Controlled Polymer Architectures.
abstract: Here, we exploit the selectivity of photoactivation of thiocarbonylthio compounds to implement two distinct organic and polymer synthetic methodologies: (1) a single unit monomer insertion (SUMI) reaction and (2) selective, controlled radical polymerization via a visible-light-mediated photoinduced electron/energy transfer-reversible addition-fragmentation chain transfer (PET-RAFT) process. In the first method, precise single unit monomer insertion into a dithiobenzoate with a high reaction yield (>97%) is reported using an organic photoredox catalyst, pheophorbide a (PheoA), under red light irradiation (λmax = 635 nm, 0.4 mW/cm(2)). The exceptional selectivity of PheoA toward dithiobenzoate was utilized in combination with another catalyst, zinc tetraphenylporphine (ZnTPP), for the preparation of a complex macromolecular architecture. PheoA was first employed to selectively activate a dithiobenzoate, 4-cyanopentanoic acid dithiobenzoate, for the polymerization of a methacrylate backbone under red light irradiation. Subsequently, metalloporphyrin ZnTPP was utilized to selectively activate pendant trithiocarbonate moieties for the polymerization of acrylates under green light (λmax = 530 nm, 0.6 mW/cm(2)) to yield well-defined graft co-polymers.
authors.affiliation: Centre for Advanced Macromolecular Design (CAMD), ‡Australian Centre for NanoMedicine, §Materials Energy Research Laboratory (MERLin), School of Chemical Engineering, The University of New South Wales Australia , Sydney, NSW 2052, Australia.
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Xu
authors.affiliation: Centre for Advanced Macromolecular Design (CAMD), ‡Australian Centre for NanoMedicine, §Materials Energy Research Laboratory (MERLin), School of Chemical Engineering, The University of New South Wales Australia , Sydney, NSW 2052, Australia.
authors.forename: Sivaprakash
authors.initials: S
authors.lastname: Shanmugam
authors.affiliation: Centre for Advanced Macromolecular Design (CAMD), ‡Australian Centre for NanoMedicine, §Materials Energy Research Laboratory (MERLin), School of Chemical Engineering, The University of New South Wales Australia , Sydney, NSW 2052, Australia.
authors.forename: Changkui
authors.initials: C
authors.lastname: Fu
authors.affiliation: Centre for Advanced Macromolecular Design (CAMD), ‡Australian Centre for NanoMedicine, §Materials Energy Research Laboratory (MERLin), School of Chemical Engineering, The University of New South Wales Australia , Sydney, NSW 2052, Australia.
authors.forename: Kondo-Francois
authors.initials: KF
authors.lastname: Aguey-Zinsou
authors.affiliation: Centre for Advanced Macromolecular Design (CAMD), ‡Australian Centre for NanoMedicine, §Materials Energy Research Laboratory (MERLin), School of Chemical Engineering, The University of New South Wales Australia , Sydney, NSW 2052, Australia.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Boyer