Tetrafluorophthalic Acid Research Articles

Formation of 1,1,3,3-tetrafluorophthalans in reactions of phthalic and pyromellitic acids with sulphur tetrafluoride

Phthalic and pyromellitic acids were previously reported to react with SF 4 giving the respective bis- and tetrakis(trifluoromethyl)benzenes as sole products. We have found that the reaction with tetrafluorophthalic acid 1a and 4,5-bis(trifluoromethyl)phthalic acid 1b afford, beside the expected poly(trifluoromethyl)benzenes 2a and 2b, considerable amounts of 1,1,3,3- tetrafluorophthalans 3a and 3b. ▪ Similarly, from pyromellitic acids 4a and 4b mixtures of tetrakis(trifluoromethyl)benzenes 5a, 5b, phthalans 6a, 6b and benzodifurans 7a, 7b were obtained. ▪ Structural factors in the acids influencing the competitive formation of (trifluoromethyl)benzenes and cyclic phthalans will be discussed.

Ionic species produced on gamma radiolysis: Studies by matrix isolation technique—I. Electronic absorption spectra of perfluorosubstituted aromatic radical anions

The absorption spectra of several perfluorosubstituted aromatic radical anions are compared with the corresponding perhydro compounds in which the various transitions involved have been assigned to those predicted theoretically. The electronic absorption spectra were obtained for pentafluorostyrene, pentafluorobenzaldehyde, pentafluorobenzoic acid, pentafluorobenzonitride, tetrafluorophthalic acid and pentafluoroaniline, by gamma radiolysis in 2-methyltetrahydrofuran at 77 K. A general similarity in the absorption spectra between the perfluorinated and the corresponding perhydro radical anion is observed except for a shift in the absorption band.

Aromatic polyfluoro-compounds—XXXV : 1,2,3,4-tetrafluoroanthraquinone and some reactions of tetrafluorophthalic acid derivatives

1,2,3,4-Tetrafluoroanthraquinone has been synthesized and some of its reactions studied Further reactions of tetrafluorophthalic acid and its derivatives are reported.