THE MASS-SPECTROMETRIC BEHAVIOR OF SOME IRIDIUM(I) AND IRIDIUM(III) PYRAZOLATE DERIVATIVES

The mass spectrometric behaviour of a series of monomeric iridium(I) and iridium(III) pyrazolates, Ir(PPh3)2(CO)(pz-N) (1-3) and Ir(PPh3)2(CO)(H)2(pz-N) (4-6) (1 and 4: pzH = 3,5-dimethylpyrazole; 2 and 5: pzH = 3,5-bis(trifluoromethyl)pyrazote; 3 and 6: pzH = 3,5-dimethyl-4-nitropyrazole), has been studied in detail with the aid of linked scans and mass analysed ion kinetic energy spectra. The differences observed as a function of the substituents on the pyrazolate ligands are described, and a comparison with the results previously reported for homologous rhodium(I) derivatives is made. The reactions leading, under the experimental conditions, to binuclear species or to orthometallated derivatives are discussed.