Chemistry Letters, Vol.38, No.1, 14-15, 2009
Metal Ion Sensing by Luminescence from an Ion-exchange Adduct of Clay and Cationic Cyclometalated Iridium(III) Complex
A cationic iridium(III) complex, [Ir(ppy)(2)dmbpyl] (ppy = 2-phenylpyridine and dmbpy = 4,4'-dimethylbipyridine), was adsorbed by colloidally dispersed montmorillonite clay. The emission quantum yield (Phi) decreased from 0.06 to 0.01 on adsorption, while Phi recovered to ca. 0.12 by adding alkali or alkaline earth metal ions to the concentration of ca. 2 x 10(-2) or 2 x 10(-5) M, respectively.