Formation of Organometallic Species, [M – H]⁺ Ions and Radical Cations upon Mass Spectrometric Fragmentation of Mercury–Crown Ether Complexes

Abstract

Mass spectrometric fragmentation pathways of [M + HgClO(4)](+) (M - crown ether molecule), determined by tandem mass spectrometry experiments, are discussed in detail. The decomposition of [M + HgClO(4)](+) proceeds along three fragmentation pathways: formation of [M - H](+) ions, formation of organometallic species, namely [M - H + Hg](+) ions, and formation of radical cations [M](+*). The factors influencing these processes, namely crown ether cavities and the presence of electron withdrawing/electron donor groups, have been discussed.

Cation–π interactions in gas‐phase complexes formed by benzo‐crown ethers and alkali metal cations

“…[12,14] Interactions of the aromatic ring of benzo-crown ethers with transition metal cations, namely Cu 2þ and Hg 2þ , have been also found to take place. [13,15] Crown ethers with aromatic side-arms exhibited cation-p interactions between K þ and a benzene ring; [16] however, cation-p interactions have not yet been observed for complexes of benzo-crown ethers with alkali metal cations. In this paper it is shown that cation-p interactions may enhance the formation of sandwich benzo-crown ether-alkali metal cation complexes in the gas phase.…”

Demethoxycurcumin-Metal Complexes: Fragmentation and Comparison with Curcumin-Metal Complexes, as Studied by ESI-MS/MS

“…Decompositions of this ion lead to the formation of fragment ions [Curc-H] + and [dCurc-H] + ; thus the loss of neutral species [dCurc-H + Ga] and [Curc-H + Ga] takes place, respectively(Figure 2(b), formally gallium reduction Ga 3+ → Ga 1+ takes place). Positive ions of the type [M-H] + are rather rare in mass spectrometry (M stands for a neutral organic molecule), but sometimes they are observed[45]. The loss of [dCurc-H + Ga] occurs with higher efficiency than the loss of [Curc-H + Ga] which Bond orders of [dCurc + H] + ion.…”