| Abstract: | Further evidence supporting the structure of the M ? 1]+ ion found in the mass spectrum of flavone as being the dibenzo-β-tropolone ? H]+ species was obtained by comparison of linked scan measurements performed in flavone, 3-deuteroflavone, 5,6,7,8-tetradeuteroflavone, 2′,3′,4′,5′,6′-pentadeuteroflavone and dibenzo-β-tropolone. This fragmentation process has also been demonstrated in the case of 3-methoxyflavone by high-resolution measurements, deuterium labelling, metastable decompositions and evaluation of the subspectra of 9-methoxyfluorenol, fluorenone and biphenylene. The structure of the ion at m/z 181 in the spectrum of flavone was found to be the 2-phenylbenzoxetane ? 1]+ species. |
