Transition metal ions (Pb2+, Zn2+, Cd2+, Co2+, Mn2+, Cu2+, Ni2+, Hg2+, Ag+, Fe3+) in water are used to quench emission of 2-(6-oxido-6H-dibenz<c,e><1,2>oxaphosphorin-6-yl)-1,4-phenylene-bis(p-pentyloxylbenzoate)s (MD5) with aggregation-induced emission enhancement (AIEE) in water-acetonitrile (AN) mixture (80:20 by volume). Among all metal ions, Fe3+ exhibits the highest quenching efficiency on AIEE of MD5 even when the concentration of Fe3+ is lower than 1×10?6?mol/L. The quenching efficiency of Hg2+ is lower than that of Fe3+ at the same concentration, though MD5 is used to detect Hg2+ efficiently, too. To other metal ions, low quenching efficiency has few relations with a wider concentration range. The UV absorbance spectra show only red shift of absorbance wavelength in the presence of Hg2+ and Fe3+, which indicates a salt-induced J-aggregation. SEM photos reveal larger aggregation and morphological change of nanoparticles of MD5 in water containing Hg2+ and Fe3+, which reduce the surface area of MD5 emission for further aggregation. The selective quenching effect of transition metal ions to emission of MD5 has a potential application in chemical sensors of some metal ions. |