6H4 NHCOR (X = NH, S, O; R = CF3, C2F5, C3F7). Only para-isomers showed su" />
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Publication Citation: Unique para-effect in electron ionization mass spectra of bis(perfluoroacyl) derivatives of bifunctional aminobenzenes

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Author(s): Kirill V. Tretyakov; Nino G. Todua; Roman S. Borisov; Vladimir G. Zaikin; Stephen E. Stein; Anzor I. Mikaia;
Title: Unique para-effect in electron ionization mass spectra of bis(perfluoroacyl) derivatives of bifunctional aminobenzenes
Published: September 15, 2010
Abstract: A new kind of "para-effect" under EI conditions has been discovered for a series of bis(perfluoroacyl) derivatives of o-, m- and p- phenylendiamines, hydroxybenzeneamines and mercaptobenzeneamines of a common structure RCOX C6H4 NHCOR (X = NH, S, O; R = CF3, C2F5, C3F7). Only para-isomers showed successive loss of radical RCO and molecule RCN, leading to very intense peaks in the EI spectra. The composition and the origin of the [M - COR - NCR]+ ions were confirmed by exact mass measurements and linked scan experiments. The proposed mechanism of their formation takes into account likely para-quinoid structures of the precursor ions. A similar rearrangement has not been observed for para-isomers in the series of bis(perfluoroacyl) derivatives of benzenediols, mercaptophenols and dimercaptobenzenes.
Citation: Rapid Communications in Mass Spectrometry
Volume: 24
Issue: 17
Pages: pp. 2529 - 2532
Keywords: bifunctional benzenes; bis(perfluoroacyl) derivatives; electron ionization mass spectra; para-effect
Research Areas: Mass Spectrometry