Insoluble Polybromides of Quaternary Ammonium Salts and Their Phase-Transitions in the Presence of Aqueous Bromine-Bromide Solution

By progressive addition of bromine to aqueous 1.0 F NaBr solutions containing quaternary ammonium bromides, the precipitation and phase transitions of tetramethylammonium‐, tetrabuthylammonium‐, and phenyltrimethyl‐ammonium polybromides have been potentiometrically detected at constant temperature. The results show existence of solid TMABr 3,9 , TBABr 3,7,8,9,11 , and PhTMABr 3,5,7 . Addition of bromine to a saturated TMAClO 4 solution leads to the precipitation of only TMABr 9 .