88073-76-1Relevant academic research and scientific papers
ACID-BASE CHARACTERISTICS OF 4-SUBSTITUTED 4-PHENYLAZOBENZENE-DIAZONIUMS
Bagal, I. L.,Mileiko, V. E.,El'tsov, A. V.
, p. 1493 - 1505 (2007/10/02)
4-Substituted 4-phenylazobenzenediazonium compounds and the products from their reaction with aqueous alkali and sodium sulfite were investigated by IR and UV spectroscopy.The constants of the acid-base equilibria were determined by a spectral method and by the kinetics of azo coupling.It was shown that the acidity of the diazonium cations is higher than the acidity of the corresponding diazohydroxides.This gives rise to a high equilibrium concentration of the diazohydroxides and to low stability in the alkaline solutions of the diazo compound.Cations of the 4-phenylazobenzenediazonium series are softer acids than the cations of the benzenediazonium series.On account of the low conductivity of the phenylazo group the salts of 4-phenylazobenzenediazoniums with electron-donating substituents are considerably more active than their analogs of the benzene series; the pattern is reversed in the case of electron-withdrawing substituents.
