A new water-soluble and acid-stable dinuclear organoiridium(III) dinitrate complex [{Cp*Ir(NO3)}(2)(mu-Cl)(2) (1, C-p* = eta(5)-C5Me5) was synthesized by the reaction of a water-insoluble organoiridium(III) complex [(Cp*IrCl)(2)(mu-Cl)(2)] (2) with two equivalents of AgBF4 in aqueous nitric acid (1 M HNO3/H2O) at 23 degrees C for 12 h. The structure of 1 with two monodentate NO3- ligands is discussed in comparison with structure of a mononuclear organoiridium(III) complex with one monodentate and one bidentate NO3- ligands, [Cp*Ir(NO3)(2)] (3).