SPECTROPHOTOMETRIC STUDY OF BASICITY OF SOME SUBSTITUTED ALPHA-(BENZAMIDOMETHYL)PHENYLHYDRAZINES

The protonation behavior at 25 degrees C in water and in aqueous sulfu ric acid solutions of some substituted alpha-(p-R-benzamidomethyl)phen yl hydrazines (R=H, CH3, Cl, Br) was investigated by UV spectrophotome try. The absorption spectra in sulfuric acid solutions were analyzed b y the method of multivariate analysis. The protonation constants of hy drazine (pK(1)) and amide (pK(2)) moieties were determined; pK(2) valu es were calculated from the reconstituted absorption spectra by Cox - Yates method. Dependence of pK(2) on Hammett's sigma constants was dis cussed.