Synthesis and Characterization of Iridium Organometallic Complexes Covalently Grafted to Mesoporous Silicates and their Application on Removal of Heavy Metal Ions from Aqueous Solution

In the present paper, a cyclometalated thiolated bridged iridium dimmers [(L)2IrS(CH2)3OH]2 where L is a bidentate cyclometalated ligand, 2,5-di(thiophen- 2-yl) pyridine (dtp) (1) and 2-benzo [4,5] thienyl pyridine (btp) (2) were covalently bonded into silicate framework by hydrolysis and condensation reaction. The new nanohybrid materials were fully characterized by Fourier trans-form infrared spectroscopy (FTIR), X-ray diffractometer (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results confirmed successful doping of the silicates with phosphorescent iridium organometallic complex. The TEM studies have suggested the nanoparticles nature. The prepared nanohybrids were found to be effective adsorbent for the removal of metal ions such as chromium (Cr2+), copper (Cu2+), cobalt (Co 2+), lead (Pb2+) and zinc (Zn2+) ions and from aqueous solutions.