Studies in Negative-Ion Mass Spectrometry. XII. Electron Attachment to a Series of Bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)-metal Complexes

Abstract

Results of electron-attachment reactions in the gas phase as well as negative-ion mass spectra are given for a series of bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)metal(1) complexes, (ML₂), with the divalent metals Mg^II, Mn^II, Co¹¹, Ni^l1, Cu¹¹ and Zn^II. While molecular, [ML₂]^- or [ML₂]^-, and ligand, [L]^-, ions are present in the negative-ion mass spectra, the lability of the ligand C-F and C-CF₃ bonds enables rearrangement processes involving fluorine atom transfers to become significant in the decompositions of both molecular and fragment ions, particularly for the class (a) metals, for which significant yields of [MLF₂] and [MLF] negative ions were obtained. Thus, the predominant fragmentation pathway for such metal-containing complexes, for which metastable peaks have been assigned, occurs in the sequence

[ML₂]^- -(*) → (MLF₂]^- - (8) → [L]^-

or alternatively

[ML₂]^- -(*) → (MLF₂]^- - (8) → [L]^-

with the latter fragmentation in these sequences involving the elimination of the divalent metal fluoride, MF₂.