Formation of negative ions from cobalt tricarbonyl nitrosyl Co(CO) 3 NO clusters.

Electron attachment and corresponding dissociative electron attachment (DEA) to cobalt tricarbonyl nitrosyl (Co(CO) 3 NO) clusters have been studied by co-expansion with Ar gas into a high vacuum. A monochromatic electron beam was utilized to generate negative ions and the resulting reaction products were identified using mass spectrometry. The ion fragments corresponding to Co(CO) 3 NO monomers closely resemble results from earlier gas phase experiments and studies conducted on Co(CO) 3 NO in He nanodroplets. However, contrary to the gas phase or He nanodroplet ion yields, a resonance structure comprising several peaks at energies above ∼4 eV was observed both in the case of molecular clusters [Co(CO) 3 NO] n - (with n = 1, 2, 3) and clusters comprising DEA fragments. Additionally, the ion yields of numerous other clusters such as ions without nitrosyl ([Co(CO) 4 ] - , [Co 2 (CO) 5 ] - ), clusters consisting of two fragments such as ([Co 2 (CO)NO] - , [Co 2 (CO)(NO) 2 ] - , [Co 2 (CO) 2 NO] - , [Co 2 (CO) 2 (NO) 2 ] - , [Co 3 (CO)(NO) 3 ] - , [Co 3 (CO) 8 (NO) 3 ] - , [Co 3 (CO)(NO) 2 ] - , [Co 3 (CO) 3 (NO) 2 ] - , and [Co 3 (CO) 5 (NO) 2 ] - ) were recorded. Moreover, NO bond dissociation was confirmed with the [Co(CO) 2 N] - ion and with N- or O-retaining cluster ions, such as [Co 2 (CO)(NO)N] - , [Co 2 (CO) 2 (NO)N] - , [Co 3 (CO) 2 (NO)N] - , [Co 3 (CO) 3 (NO)N] - and [Co 3 (CO)(NO) 2 N] - , or [Co 2 (CO) 2 O] - , [Co 2 (CO) 3 O] - , [Co 3 (CO) 3 O] - , [Co 3 (CO) 4 O] - and [Co 3 (CO) 2 (NO)O] - respectively.