Cooperative Supramolecular Polymerization of Propeller-Shaped Triphenylamine Cyanostilbenes for Explosive Detection.

Self-assembly of π-conjugated compounds into supramolecular polymers has received considerable attention because of their intrinsic scientific interests and technological applications. As compared to π-conjugated rods, discotics, and macrocycles, propeller-shaped π-conjugated molecules have been less exploited to form long-range-ordered supramolecular polymers. Herein a novel type of supramolecular polymers has been constructed on the basis of propeller-shaped triphenylamine cyanostilbenes. The designed compound adopts nucleation—elongation cooperative mechanism for the supramolecular polymerization process, because of the participation of three-fold hydrogen bonds between the neighbouring monomers. The supramolecular polymeric state displays amplified chirality and enhanced emission than those in the monomeric state. The resulting supramolecular polymers exhibit severe emission quenching upon addition of 2,6-dinitrotoluene, ascribed to photoinduced electron transfer from the triphenylamine cyanostilbenes to the explosive analyte. The current study proves the feasibility to supramolecular polymerize propeller-like π-conjugated molecules, serving as a promising type of explosive sensor owing to their guest encapsulation and signal amplification capabilities. [ABSTRACT FROM AUTHOR]