tButyl pyrene containing poly(arylene ethynylene)s for highly sensitive and selective sensing of TNT

A series of poly(arylene ethynylene)s (PAEs) containing tbutyl pyrene in the main chain were synthesized for nitroaromatic sensors. As control, similar polymers containing unsubstituted pyrene were also synthesized. The sensory properties of the polymers were studied towards various nitroaromatic compounds like trinitrotoluene (TNT), dinitrotoluene (DNT), nitrotoluene (NT), nitrobenzene (NB) and picric acid (PA) in solution as well as vapor state. Interestingly, all the tbutyl substituted pyrene containing polymers showed higher sensitivity than the corresponding unsubstituted pyrene containing polymers. Moreover, the polymers showed high sensitivity towards TNT as compared to the other nitroaromatic compounds. The sensitivity of one of the polymer PB was found several folds higher than that of the similar reported polymer containing unsubstituted pyrene ring. In addition, tbutyl pyrene containing polymers were found to have improved molecular weight, thermal stability, fluorescence quantum yield, film forming properties and solubility in common organic solvents as compared to the control polymers.