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Updated: Jan 6, 2026

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of PhosphorusI
Published on: November 22, 2016
Photolytic, radical-mediated hydrophosphination: a convenient post-polymerisation modification route to
Alastair W Knights1, Saurabh S Chitnis1,2, Ian Manners1,3
1School of Chemistry , University of Bristol , Cantock's Close , BS8 1TS , UK.
Abstract:
Polymers with a phosphorus-boron main chain have attracted interest as novel inorganic materials with potentially useful properties since the 1950s. Although examples have recently been shown to be accessible via several routes, the materials reported so far have been limited to P-mono(organosubstituted) materials, [RHPBH2] , containing P-H groups. Here we report a general route for the post-polymerisation modification of such polyphosphinoboranes giving access to a large range of previously unknown examples featuring P-disubstituted units. Insertion of alkenes, R'CH[double bond, length as m-dash]CH2 into the P-H bonds of poly(phenylphosphinoborane), [PhHPBH2] was facilitated by irradiation under UV light in the presence of the photoinitiator 2,2-dimethoxy-2-phenylacetophenone (DMPAP) and (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) under benchtop conditions giving high molar mass, air-stable polymers [PhR'PBH2] with controlled functionalisation and tunable material properties. The mechanistic explanation for the favourable effect of the addition of TEMPO was also investigated and was proposed to be a consequence of reversible binding to radical species formed from the photolysis of DMPAP. This new methodology was also extended to the formation of crosslinked gels and to water-soluble bottlebrush copolymers showcasing applicability to form a wide range of polyphosphinoborane-based soft materials with tunable properties.
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