129277-84-5Relevant academic research and scientific papers
The Origin of Colour and EPR Spectral Phenomena During the Reaction between Acetone and the Tetrabutylammonium Tetramethylsuccinimide/N-Bromotetramethylsuccinimide Complex
Eberson, Lennart,Kubacek, Pavel
, p. 384 - 393 (2007/10/02)
The reaction between the tetrabutylammonium tetramethylsuccinimide/N-bromo-tetramethylsuccinimide complex (the T complex) and acetone produces a transient purple colour and an EPR signal (a quintet).These phenomena accompany the main reaction, which consists of successive brominations/tetramethylsuccinimido substitutions of acetone.With two of the consecutively formed products, tetramethylsuccinimidoacetone and 1,3-bis(tetramethylsuccinimido)acetone, the same phenomena appear with successively increasing intensity and also earlier during the reaction course.It is suggested that the purple colour originates in the monobromination of 1,3-bis(tetramethylsuccinimido)acetone, followed by proton abstraction and bromide loss to give the 1,3-bis(tetramethylsuccinimido)-2-oxidoallyl species.This oxyallyl derivative is a true zwitterionic chromogen, analogues of which are known to display similar colours.The EPR signal was shown to originate from a related oxyallylic species, 1,3-dibromo-1,3-bis(tetramethylsuccinimido)-2-oxidoallyl radical cation, a representative of a novel class of intermediate, ylidions.The same signal could be produced by treating either 1,1,3,3-tetrabromoacetone or pentabromoacetone with the T complex.A related ylidion, the radical cation of 2,3-bis-(N,N-diethylamino)cyclopropenone, was generated as a model.Suitable six-carbon 1,4-diketones, such as hexane-2,5-dione or cyclohexane-1,4-dione, upon treatment with the T complex gave solutions containing high concentrations of the radical anion of tetrakis(tetramethylsuccinimido)-1,4-benzoquinone.
