
%0 Journal Article
%A Gillis, RG 
%A Porter, QN 
%T The Fragment Ion C<sub>13</sub>H<sub>9</sub>O<sub>2</sub> <I>m/z</I> 197 in the Mass Spectra of 2-(2&#8242;-R-phenyl)benzoic Acids
%J Australian Journal of Chemistry
%D 1990/01/01
%V 43
%N 1
%P 203-207
%K 
%R https://doi.org/10.1071/CH9900203
%U https://www.publish.csiro.au/paper/CH9900203 
%X In the electron impact mass spectrum of 2-(2&#176;-R-phenyl)benzoic acids where R=H, NO2, OCH3, COOH, or Br, an abundant fragment ion m/z 197 is formed by an ipso substitution in which R is expelled as a radical. The structure of the ion m/z 197 has been shown by collision-activated dissociation to be identical with that of the protonated molecule formed by methane chemical ionization of 6H-dibenzo[ b,d ]pyran-6-one. 
