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The effect of ion source temperature on the fragmentation of 2‐pentanone
Author(s) -
Wood K. V.,
McLuckey S. A.,
Cooks R. Graham
Publication year - 1986
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210210104
Subject(s) - ion , dissociation (chemistry) , fragmentation (computing) , chemistry , enol , molecule , spectral line , collision induced dissociation , mass spectrometry , analytical chemistry (journal) , catalysis , tandem mass spectrometry , organic chemistry , physics , chromatography , astronomy , computer science , operating system
Abstract A dramatic source temperature effect is observed in the low collision energy collision‐induced dissociation spectra of molecular ions derived via 70 eV electron bombardment of 2‐pentanone and via charge exchange. The observation cannot simply be attibuted to the increased thermal energy of the 2‐pentanone molecular ions. A number of factors appear to contribute to the observed results, (i) the increase, with temperature, in the ratio of the concentration of enol to keto neutral molecules, (ii) temperature effects on the Franck‐Condon factors which control the yields and internal energies of the keto and enol molecular ions, (iii) differences in the relative stabilities of the keto and enol molecular ions, (iv) temperature effects on the equilibrium between the isomeric molecular ions. This last item is probably most important, with the concentration ofbeing most significant. These data highlight the role that ion source temperature can play as a variable in elucidating ion structure problems.