Phosphorescent Azacrown Ether-appended Iridium (III) Complex for the Selective Detection of Hg2+ in Aqueous Acetonitrile

A new phosphorescent cyclometalated heteroleptic iridium (III) complex with an ancillary ligand of 4-azacrown-picolinate was prepared and its metal ion selective phosphorescent chemosensing behavior was investigated. The new iridium (III) complex exhibits notable phosphorescence quenching for Hg2+ in aqueous 50% acetonitrile solution with respect to the selective phosphorescent detection of various metal ions including Li+, Na+, K+, Cs+, Mg2+, Ca2+, Ba2+, Fe2+, Ni2+, Cu2+, Zn2+, Ag2+, Pb2+, Cd2+, Cr2+, Cr3+ and Hg2+. The phosphorescence quenching for Hg2+ increased linearly with increasing concentration of Hg2+ in the range of 10 mu M - 700 mu M even in the presence of other metal ions, except for Cu2+. Consequently, the new iridium (III) complex has the potential to be utilized for the determination of parts per million levels of Hg2+ in aqueous acetonitrile media.