Luminescent polyethylene with side-chain triarylboranes: Synthesis and fluoride sensing properties

Abstract The direct copolymerization of ethylene with an electron-deficient borane monomer ( 1 ) using a single-site catalytic system, Me 2 Si(η 5 -C 5 Me 4 )(η 1 -N- t Bu)TiCl 2 ( CGC )/methylaluminoxane (MAO) efficiently leads to the novel class of luminescent polyethylene with pendent triarylborane groups. The catalytic system provides high-molecular-weight copolymers with controlled incorporation of 1 . Characterization by multinuclear NMR spectroscopy reveals that the copolymers constitute a well-defined polymer structure with base-free tricoordinate boron centers. While UV–vis absorption and PL spectra of copolymers display almost identical absorption and emission features with those of 1 , the copolymer (8.8 mol% of 1 ) shows the enhanced emission quenching efficiency with 70% amplification effect upon addition of fluoride ion in solution. Particularly, the thin film of the copolymer exhibits the high fluorescence quenching response in the presence of a very low concentration of fluoride ion (4.5 μM) in THF.