Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry has been applied to the study of energy-resolved collisioninduced dissociation of Cr 2 (CO) y + (y = 4-7) prepared during the clustering reactions initiated by the dissociative ionization of Cr(CO) 6. Mass-selected precursor ions were activated by translational energy-controlled collisions with helium. Threshold curves for the dissociation products were analyzed using model functions convoluted with a Doppler broadening distribution function. For one CO ligand loss from Cr 2 (CO) 4 + , Cr 2 (CO) 5 + and Cr 2 (CO) 7 + , the threshold values were determined to be 1.26 ± 0.11, 1.92 ± 0.16 and 1.35 ± 0.12 eV, respectively, at 298 K. In the case of Cr 2 (CO) 6 + , the lowest energy channel was chromium ion elimination with a threshold of 1.47 ± 0.12 eV.

No abstract