Synthesis, Characterization, and Ion Sensing Application of Pyrene-Containing Chemical Probes

Abstract

A novel pyrene-functionalized thiophene compound (Thi-Pyr) and pyrene-functionalized styrene polymers (P7-9) are synthesized via 1,3-dipolar cycloaddition reaction between the azide functional groups of the precursors and 1-ethynylpyrene. Glass transition temperature of the styrene polymers increases remarkably upon the covalent attachment of the pyrene unit through triazole linkers, whereas the thermal stabilities of the styrene polymers are not affected by the incorporation of pyrene moieties. Thi-Pyr exhibits the characteristic pyrene monomer emission bands; on the other hand, P7-9 show the excimer emission bands of pyrene due to the excitation of ground state dimeric species. The monomer emissions of Thi-Pyr and the excimer emissions of P7-9 are distinguishably increased by the addition of HP2O73-, Cl-, and Br- anions. The responses of Thi-Pyr and P7-9 to the addition of HP2O73- are stronger than any other anions, indicating their selectivity to HP2O73- anion to some extent.