Gas‐phase fragmentation of metal adducts of alkali‐metal oxalate salts |
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| Authors: | Robert D Hale Chang‐Ching Chan Carl S Weisbecker Athula B Attygalle |
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| Affiliation: | Stevens Institute of Technology, Chemistry and Chemical Biology, , Hoboken, NJ, USA |
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| Abstract: | Upon collisional activation, gaseous metal adducts of lithium, sodium and potassium oxalate salts undergo an expulsion of CO2, 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 CO2 requires less energy than an expulsion of a Na+ and that the Na3CO2]+ product ion formed in this way bears a planar geometry. Furthermore, spectra of Na3C2O4]+ and 39K3C2O4]+ recorded at higher collision energies showed additional peaks at m/z 90 and m/z 122 for the radical cations Na2CO2]+? and K2CO2]+?, respectively, which represented a loss of an M? from the precursor ions. Moreover, Na3CO2]+, 39K3CO2]+ and Li3CO2]+ ions also undergo a CO loss to form M3O]+. Furthermore, product‐ion spectra for Na3C2O4]+ and 39K3C2O4]+ recorded at low collision energies showed an unexpected peak at m/z 63 for Na2OH]+ and m/z 95 for 39K2OH]+, respectively. An additional peak observed at m/z 65 for Na218OH] + in the spectrum recorded for Na3C2O4]+, after the addition of some H218O to the collision gas, confirmed that the Na2OH] + ion is formed by an ion–molecule reaction with residual water in the collision cell. Copyright © 2014 John Wiley & Sons, Ltd. |
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| Keywords: | alkali‐metal oxalates collisional activation electrospray ionization collision‐induced dissociation gaseous metal adducts sodium carbonite |
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