Pyridazine-bridged cationic diiridium complexes as potential dual-mode bioimaging probes.

A novel diiridium complex [(N^C^N)Ir(bis-N^C)Ir(N^C^N)Cl]PF (N^C^N = 2-[3--butyl-5-(pyridin-2-yl)phenyl]pyridine; bis-N^C = 3,6-bis(4--butylphenyl)pyridazine) was designed, synthesised and characterised. The key feature of the complex is the bridging pyridazine ligand which brings two cyclometallated Ir(iii) metal centres close together so that Cl also acts as a bridging ligand leading to a cationic complex. The ionic nature of the complex offers a possibility of improving solubility in water.

When two are better than one: bright phosphorescence from non-stereogenic dinuclear iridium(III) complexes.

A new family of eight dinuclear iridium(iii) complexes has been prepared, featuring 4,6-diarylpyrimidines L(y) as bis-N^C-coordinating bridging ligands. The metal ions are also coordinated by a terminal N^C^N-cyclometallating ligand L(X) based on 1,3-di(2-pyridyl)benzene, and by a monodentate chloride or cyanide. The general formula of the compounds is {IrL(X)Z}2L(y) (Z = Cl or CN).