J. Rimlinger et al., MASS-SPECTROMETRIC INVESTIGATION OF SOME ALPHA-TRIFLUOROMETHYL-ALPHA-AMINO ACIDS, Journal of mass spectrometry., 32(9), 1997, pp. 1002-1007
he fast atom bombardment-induced mass spectrometric behaviour of four
fluorinated alpha-amino acids was studied in detail with the aid of me
tastable ion studies anal accurate mass measurements. Comparison with
that behaviour of unfluorinated analogues suggests that the presence o
f fluorin makes the carbonylic oxygen the mast prone to protonation, T
his hypothesis was confirmed by AM1 semiempirical calculations which i
ndicate that the carbonylic oxygen of the carboxyl group exhibits, in
the case of fluorinated components only, the highest proton affinity.
(C) 1997 by John Wiley & Sons, Ltd.