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Gas‐phase fragmentation of metal adducts of alkali‐metal oxalate salts
Author(s) -
Hale Robert D.,
Chan ChangChing,
Weisbecker Carl S.,
Attygalle Athula B.
Publication year - 2014
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.3322
Subject(s) - chemistry , alkali metal , adduct , fragmentation (computing) , metal , oxalate , gas phase , inorganic chemistry , phase (matter) , organic chemistry , computer science , operating system
Upon collisional activation, gaseous metal adducts of lithium, sodium and potassium oxalate salts undergo an expulsion of CO 2 , followed by an ejection of CO to generate a product ion that retains all three metals atoms of the precursor. Spectra recorded even at very low collision energies (2 eV) showed peaks for a 44‐Da neutral fragment loss. Density functional theory calculations predicted that the ejection of CO 2 requires less energy than an expulsion of a Na + and that the [Na 3 CO 2 ] + product ion formed in this way bears a planar geometry. Furthermore, spectra of [Na 3 C 2 O 4 ] + and [ 39 K 3 C 2 O 4 ] + recorded at higher collision energies showed additional peaks at m/z 90 and m/z 122 for the radical cations [Na 2 CO 2 ] +• and [K 2 CO 2 ] +• , respectively, which represented a loss of an M • from the precursor ions. Moreover, [Na 3 CO 2 ] + , [ 39 K 3 CO 2 ] + and [Li 3 CO 2 ] + ions also undergo a CO loss to form [M 3 O] + . Furthermore, product‐ion spectra for [Na 3 C 2 O 4 ] + and [ 39 K 3 C 2 O 4 ] + recorded at low collision energies showed an unexpected peak at m/z 63 for [Na 2 OH] + and m/z 95 for [ 39 K 2 OH] + , respectively. An additional peak observed at m/z 65 for [Na 2 18 OH] + in the spectrum recorded for [Na 3 C 2 O 4 ] + , after the addition of some H 2 18 O to the collision gas, confirmed that the [Na 2 OH] + ion is formed by an ion–molecule reaction with residual water in the collision cell. Copyright © 2014 John Wiley & Sons, Ltd.