Dolman, Douglas published the artcileAn acidity function in ethanol-sulfuric acid based on the protonation of diphenylamines, Recommanded Product: Bis(4-nitrophenyl)amine, the publication is Canadian Journal of Chemistry (1967), 45(9), 903-10, database is CAplus.
A Hammett H0 acidity function based on the protonation of 17 diphenylamines in 20 volume % EtOH-aqueous H2SO4 has been established. The H0 value for the most acidic solution studied (11.2M H2SO4) is -6.97. This acidity function differs from that based on the protonation of azobenzenes in the same solvent system; the latter diverges to more neg. H0 values as the sulfuric acid concentration increases. The pKBH+ values for the protonation of the diphenylamines vary from +1.36 for 4-methoxydiphenylamine to -6.21 for 4,4′-dinitrodiphenylamine. A plot of log KBH+ vs. the Hammett ¦Ò constants for five monosubstituted diphenylamines yields a ¦Ñ value of +3.36. The pKBH+ values for 4-methoxy-, 4-methyl-, 4-methylsulfonyl-, and 4-nitro-diphenylamine are all less (more neg.) than expected from the Hammett substituent constants The substituent effects on the basicities of aniline and diphenylamine are the same. The basicities of several nitro-substituted diphenylamines appear to vary regularly, and do not reflect the presence of a strong interaction between the nitro group and H2SO4. 43 references.
Canadian Journal of Chemistry published new progress about 1821-27-8. 1821-27-8 belongs to catalysis-chemistry, auxiliary class Nitro Compound,Amine,Benzene, name is Bis(4-nitrophenyl)amine, and the molecular formula is C12H9N3O4, Recommanded Product: Bis(4-nitrophenyl)amine.
Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia