The ion kinetic energy spectra of some aromatic hydrocarbons

Abstract

The technique of ion kinetic energy spectroscopy has been applied to the study of the aromatic hydrocarbons benzene, toluene, naphthalene, 2-methyl naphthalene, biphenyl and anthracene. The method is illustrated by a complete study of naphthalene in which transitions of metastable doubly-and singly-charged ions are listed, including reactions in which singly-charged ions are formed by collision induced chargeexchange reactions of doubly-charged ions and by the double process of charge-exchange and metastable decomposition with loss of one or two hydrogen atoms.Decompositions of doubly-charged ions into two singly-charged ions, together with the kinetic energies released in these decompositions, are also given for all the compounds studied.

Charge permutation reactions in tandem mass spectrometry

“…KER carries valuable information concerning both the structures of the species involved and the energetics and dynamics of the reaction. 80,86 The amount of kinetic energy released can be calculated from the widths of peaks in ion kinetic energy spectra and the distance between the two charges at the moment of decomposition, estimated by 5,87 r Å D 14.40/KER eV can be used to infer information regarding the structures and geometries of precursor ions. 88,89 For example, the MIKE spectrum and B/E spectrum of the M 2C ion of indole 90 are shown in Fig.…”

“…at the intersection of two diabatic potential energy curves with interpartical separations of 2-6Å, corresponding to the so-called 'reaction window' resulting in a high probability for the net electron transfer for reactants at this range of distances. 110,115,127 This reaction has been studied via tandem mass spectrometry with both reverse-and forward-geometry sector mass spectrometers by Beynon and co-workers 86 It has been demonstrated that isomeric compounds can be readily distinguished by comparing their 2E mass spectra, even if their singly charged ion mass spectra are identical. 131 Although most of the work has been carried out with small dictations, multiply charged macro-ions, including C 60 and related fullerene compounds, have been subjected to studies of this kind.…”

Direct analysis of complex mixtures by mass spectrometry

“…For example, it is useful in recognizing aromatic hydrocarbons from a mixture. 82 The selective scan can be performed on other types of tandem in space MS/MS instruments, for example, a triple quadrupole can be scanned so that Q3 (the second mass analyzer) is linked to the scan of Q1 (the first mass analyzer) in such a way that ions are transmitted through both analyzers if their mass/charge ratio increases by a factor of exactly two in the collision region (Q2) between the two analyzers. This is achieved by scanning Q3 at twice the rate of Q1 and this too has been demonstrated.…”

From large analogical instruments to small digital black boxes: 40 years of progress in mass spectrometry and its role in proteomics. Part I 1965–1984

“…However, in 1973 John Beynon and coworkers at the Department of Chemistry at Purdue would describe the instrumental development of the mass‐analyzed ion kinetic energy (MIKE) Spectrometer 52. The design of this instrument was based on earlier work by the same group on the ion kinetic energy (IKE) spectra of organic molecules53 and, although initially used to define the energetics of ion decomposition reactions, it was with this instrument combined with a soft ionization technique, such as chemical ionization, with which the Purdue team would, a few years later, prove the feasibility of direct mixture analysis54, 55 (shown below).…”

“…Within this 2‐year period there was a flurry of additional activity reported on promising applications of the new MS/MS technique, as indicated by McLafferty in his review in Accounts of Chemical Research 72. Of all these reports, those from the group of Cooks et al at Purdue,53, 54 utilizing a MIKE spectrometer (i.e. a reversed‐geometry double‐sector mass spectrometer), must be highlighted as they demonstrated for the first time full direct (nonchromatographic) analysis of mixtures via MS, both for positive and negative ions.…”