Energy-dependent electrospray ionization mass spectrometric studies of mononuclear metal carbonyls

Energy-dependent electrospray ionization mass spectrometry (EDESI-MS) technique has been used for investigating the fragmentation of monomeric metal carbonyl complexes of general formula [M(CO)_x(COOMe)]⁻ (M = Cr, Fe, Mo, and W). The results show that in addition to the loss of CO, formaldehyde loss provides a pathway of fragmentation. Of all complexes investigated, the chromium complex exhibits the cleanest fragmentation. At very high voltages, the metal ions is either associated with a hydride or a methoxide ions.