Akademik Veri Yönetim Sistemi
The Analyst, cilt.112, sa.10, ss.1373-1376, 1987 (SCI-Expanded)
The basicities of 22 derivatives of aniline with methyl, amino, hydroxy, chloro, bromo, iodo, nitro and carboxy substituants were determined potentiometrically against a standard in nitrobenzene solvent. Methyl, amino and hydroxy substituents had a basicity-increasing effect and the others a basicity-decreasing effect on aniline. The basicity-increasing effects of each substituent differs depending on whether it is at the ortho, meta or para position. The basicity-increasing order of methyl and amino substituents is p > m > o, whereas that of the hydroxy substituent is p > o > m. Halogens, nitro and carboxy substituents all decrease the basicity of aniline. The basicity-decreasing order of the halogens is o > m > p, and moreover is in the order I > Br > CI for para derivatives and Br > CI for ortho and meta derivatives. The basicity-decreasing effect of a nitro substituent is in the order o > p > m, whereas that of a carboxy substituent is p > o > m. Among the isomers of ortho- and para-orienting substituents, para isomers, and among the isomers of meta-orienting substituents meta isomers are the most basic. Of the substituents, the basicity-increasing effects decrease in the order NH2 > OH > CH3 and the basicity-decreasing effects in the order N02 > COOH > I > Br > CI.