Electron Attachment and Electron Ionization of Helium Droplets Containing Clusters of C60 and Formic Acid
High-resolution mass spectra of helium droplets doped with C60 and formic acid (FA) are ionized by electrons. Positive ion mass spectra reveal cluster ions [(C60)pFAn]+ together with their hydrogenated and dehydrogenated counterparts. Also observed are ions containing one or more water (W) molecules. The abundance distributions of these ions reveal several interesting features: i) [(C60)pFAn]+ ions are more abundant than hydrogenated [(C60)pFAnH]+ ions even though the opposite is true in the absence of C60 (i.e. if p = 0); ii) although [C60FA]+ is the most abundant ion containing a single C60, multiple C60 suppress the [(C60)pFA]+ signal; iii) an enhanced stability of [(C60)pW1FA5H]+ and [(C60)pW2FA6H]+ mirrors that of [W1FA5H]+ and [W2FA6H]+, respectively. On the other hand, the enhanced stability of [C60FA6H]+ finds no parallel in the stability pattern of [FAnH]+ or FAn+. Negative ion mass spectra indicate a propensity for non-dissociated [(C60)pFAn]- anions if p ≥ 1 which contrasts with the dominance of dehydrogenated [FAn-H]- anions.
International Journal of Mass Spectrometry
Digital Object Identifier (DOI)
M. Mahmoodi-Darian, E.J. Al Maalouf, S. Zöttl, P. Scheier, O. Echt, Electron Attachment and Electron Ionization of Helium Droplets Containing Clusters of C60 and Formic Acid, Int. J. Mass Spectrom. 450 (2020) 116293, DOI: 10.1016/j.ijms.2020.116293, Jan 2020.