Effects of 1, 3, 5-Triazinyl Groups on the Absorption Spectra of Aromatic Amines

Abstract

A number of N-1, 3, 5-triazinyl derivatives of m- and Prsubstituted anilines containing -Cl, -OCHg, and -NEt2 groups in the 1, 3, 5-triazine nucleus 'were synthesized and their ultraviolet absorption spectra were measured in cyclohexane and methanol. ln every case, it was found that a linear re1ation holds between, the shifts (dy) of L.bands of substituted anilines upon 1, 3, 5-triazinylationand the a- values of substituents in aniline nucleus, and that the more the two substituents in 1, 3, 5-triazine nucleus becomes electron-attractive the more the reaction constants for the shift becomes large, Similar relations were also observed between the shifts upon 1, 3, 5-triazinylation and the d values of substituents of 4'-substituted 4-aminoazobenzenesi
In these N-1, 3, 5-triazinyl aromaticamines, linear relations were observed between the Zom values of twe substituentsint the 1, 3, 5-triazine nucleus and the wave numbers of La bands; slopes of thelines are considered to indicate the electron-withdrawing capacities ef the aromatic systems. When the slopes(cm-1/ b)of the lines are plotted against the values upon 1, 3, 5-triazinylation, an almost linear relation was obtained in every case, showing that the electron-attracting capacity of the aromatic system plays animportant role for the shift.