Turn-on of the fluorescence of tetra(4-pyridylphenyl)ethylene by the synergistic interactions of mercury(II) cation and hydrogen sulfate anion

The fluorescence of tetra(4-pyridylphenyl) ethylene (1) can be switched on significantly by the synergistic interactions of Hg2+ and HSO4- based on a new aggregation mechanism for tetraphenylethylene molecules.