Cationic Heteroleptic Cyclometalated IridiumIII Complexes Containing Phenyl-Triazole and Triazole-Pyridine Clicked Ligands
Marco Felici, Pablo Contreras-Carballada, Jan M. M. Smits, Roeland J. M. Nolte, René M. Williams, Luisa De Cola and Martin C. Feiters 
Molecules 2010, 15(3), 2039-2059; doi:10.3390/molecules15032039

Novel heteroleptic iridium complexes containing the 1-substituted-4-phenyl-1H-1,2,3-triazole (phtl) cyclometalating ligand have been synthesized. The 3+2 Huisgen dipolar cycloaddition method (‘click’ chemistry) was utilized to prepare a class of bidentate ligands (phtl) bearing different substituents on the triazole moiety. By using various ligands (phtl-R1 and pytl-R2) (R1=adamantane, methyl and R2=adamantane, methyl, β-cyclodextrin, ursodeoxycholic acid), we prepared a small library of new luminescent ionic iridium complexes [Ir(phtr-R1)2(pytl-R2)]Cl and report on their photophysical properties. The flexibility of the clicking approach allows a straightforward control on the chemical-physical properties of the complexes by varying the nature of the substituent on the ligand.