Synthesis of highly luminescent organoboron polymers connected by bifunctional 8‐aminoquinolate linkers

Abstract

AbstractNew organoboron aminoquinolate‐based polymers linked by π‐conjugated bridge were prepared by Sonogashira–Hagihara coupling of organoboron aminoquinolate‐based bisiodo monomers bearing biphenyl or bithiophene moiety with 1,4‐diethynylbenzene derivatives. Tetracoordination states of boron atoms in the obtained polymers were confirmed by 11B NMR spectroscopy, and they were also characterized by 1H NMR and IR spectroscopies and size‐exclusion chromatography. Their optical properties were studied by UV–vis absorption and photoluminescence spectroscopies. In the region above 400 nm, the polymers prepared from 1,4‐diethynyl‐2,5‐dioctyloxybenzene showed bathochromic shifts when compared with those prepared from 1.4‐diethynyl‐2‐perfluorooctyl‐5‐trifluoromethylbenzene. The polymers with biphenyl moiety showed higher absolute fluorescence quantum yields (ϕF = 0.28 and 0.65), whereas those with bithiophene moiety led to decreasing of the low quantum yields (ϕF = 0.19 and 0.00). The density‐functional theory (DFT) and time‐dependent–DFT calculations of model compounds corresponding to the polymers were in good agreement with the results from UV–vis properties. The calculations revealed that the electronic structure of the polymer with bithiophene moiety is different from that with biphenyl moiety, and predicted the electron transfer from the bithiophene moiety to the π‐extended quinoline moiety in transition state. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3693–3701, 2010