Umberto Vettori

Positive and negative ion mass spectrometry of carbonylrhodium(I) derivatives of 3,5-dimethyl- and 3,5-bis(trifluoromethyl)pyrazole

Abstract The mass spectrometric behaviour of some carbonylrhodium(I) derivatives of 3,5-dimethyl- and 3,5-bis(trifluoromethyl)pyrazole (pz′H and pz″ H respectively) has been studied in detail by means of different ionization techniques (Electron Impact and Field Desorption), by recording the positive and negative ion mass spectra and by using linked scan methods for metastables. The species trans-(Ph 3 P) 2 (OC)Rh(pz″ -N) which showed an unexpected behaviour has been investigated by means of collision-al activation experiments.

The mass spectrometric behaviour 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.