Polyfluorenes with on-chain dibenzoborole units -: Synthesis and anion-induced photoluminescence quenching

The synthesis of a novel, random conjugated dialkylfluorene/dibenzoborole copolymer containing 'unprotected' B-aryldibenzoborole building blocks was investigated. The reactions were carried out using dried solvents, under inert nitrogen atmosphere and using Schlenk techniques or a glove box. Fluoride and cyanide could be detected down to a concentration of approximately 0.1 mM. The response of copolymer toward a series of anions was evaluated in photoluminescence quenching measurements, both for THF solutions and drop-cast thin films. The copolymer BPFO-10 especially responded to fluoride/cyanide and iodide addition. It was observed that the lack of selectivity between cyanide and fluoride may be of secondary importance concerning a potential application in the detection of toxic gases and their decomposition products.