Reactions of 2-(arylazo)aniline with iridium trichloride: Synthesis, characterization and structure of new cyclometallated complexes of iridium(III)

Reactions of 2-(arylazo)aniline, HL (H represents the dissociable protons upon orthometallation and HL is p-RC6H4NNC6H4–NH2; RH for HL1; CH3 for HL2 and Cl for HL3) with IrCl3 in methanol afforded orthometallated complexes of composition (L)(HL)IrCl2 (2) and (L)(MeOH)IrCl2 (3), respectively. Complex (L)(MeOH)IrCl2 (3) converted into (L)(CH3CN)IrCl2 (4) upon refluxing in acetonitrile. The X-ray structure of the complexes (L1)(HL1)IrCl2 (2a) and (L3)(CH3CN)IrCl2 (4c) have been determined and characterized unequivocally. The anionic L− binds the metal in tridentate (C, N, N) manner for all the complexes.