The team made hyperbranched polymers by the polycyclotrimerisation of tetraphenylethenes. The compounds were thermally stable with high degradation temperatures under nitrogen and in air. They are non-emissive or weakly fluorescent in solution; they become strong emitters when aggregated in poor solvents and in the solid state, demonstrating aggregation-induced or enhanced emission.
The emission of the polymer in the solution and aggregated states can be quenched efficiently by picric acid (the explosives TNT and DNT exert a similar effect to picric acid on the light emission of the polymer) with large quenching constants, suggesting that it is a promising fluorescent chemosensor for detecting explosives. Read the article for free until 14th May.
Reference: Rongrong Hu , Jacky W. Y. Lam , Jianzhao Liu , Herman H. Y. Sung , Ian D. Williams , Zhounan Yue , Kam Sing Wong , Matthew M. F. Yuen and Ben Zhong Tang, Polym. Chem., 2012, DOI: 10.1039/C2PY20057K (Advance Article)