28054-25-3Relevant academic research and scientific papers
THE EFFECTS OF CYCLIC TERMINAL GROUPS IN 4-AMINOAZOBENZENE AND RELATED AZO DYES. PART 3. ELECTRONIC ABSORPTION SPECTRA OF SOME MONOAZO DYES DERIVED FROM N-PHENYLMORPHOLINE, N-(PHENYL)THIOMORPHOLINE, N-(PHENYL)THIOMORPHOLINE 1,2-DIOXIDE, AND N-ACETYL-N'-PHENYLPIPERAZINE
Hallas, Geoffrey,Marsden, Richard,Hepworth, John D.,Mason, Donald
, p. 123 - 126 (2007/10/02)
Monoazo dyes containing a terminal morpholino group absorp hypsochromically in comparison with their piperidino counterparts as a result of electron withdrawal by the oxygen atom.Similar shifts are observed with related dyes possessing other γ-heteroatoms in the donor group.In acid solution, protonation takes place at the β-azo nitrogen atom (azonium tautomer) and at the terminal nitrogen atom (ammonium tautomer) to an extent which depends on the inductive effect of the γ-substituent.
