title: Oxidation Responsive Polymers with a Triggered Degradation via Arylboronate Self-Immolative Motifs on a Polyphosphazene Backbone.
abstract: Oxidation responsive polymers with triggered degradation pathways have been prepared via attachment of self-immolative moieties onto a hydrolytically unstable polyphosphazene backbone. After controlled main-chain growth, postpolymerization functionalization allows the preparation of hydrolytically stable poly(organo)phosphazenes decorated with a phenylboronic ester caging group. In oxidative environments, triggered cleavage of the caging group is followed by self-immolation, exposing the unstable glycine-substituted polyphosphazene which subsequently undergoes to backbone degradation to low-molecular weight molecules. As well as giving mechanistic insights, detailed GPC and1H and31P NMR analysis reveal the polymers to be stable in aqueous solutions, but show a selective, fast degradation upon exposure to hydrogen peroxide containing solutions. Since the post-polymerization functionalization route allows simple access to polymer backbones with a broad range of molecular weights, the approach of using the inorganic backbone as a platform significantly expands the toolbox of polymers capable of stimuli-responsive degradation.
authors.affiliation: Institute of Polymer Chemistry and Institute of Inorganic Chemistry, Johannes Kepler University Linz , Altenberger Straße 69, 4040 Linz, Austria.
authors.forename: Aitziber
authors.initials: A
authors.lastname: Iturmendi
authors.affiliation: Institute of Polymer Chemistry and Institute of Inorganic Chemistry, Johannes Kepler University Linz , Altenberger Straße 69, 4040 Linz, Austria.
authors.forename: Uwe
authors.initials: U
authors.lastname: Monkowius
authors.affiliation: Institute of Polymer Chemistry and Institute of Inorganic Chemistry, Johannes Kepler University Linz , Altenberger Straße 69, 4040 Linz, Austria.
authors.forename: Ian
authors.initials: I
authors.lastname: Teasdale