Analysis of the absorption spectrum of a mixture of chloranil and aniline

• Published in: BUNSEKI KAGAKU Vol. 20; no. 3; pp. 327 - 330
• Main Authors: INAZUMI, Sachi, TASHIMA, Yoko, YUKI, Hidetaka, TAKIURA, Kiyoshi
• Format: Journal Article
• Language: English; Japanese
• Published: Tokyo The Japan Society for Analytical Chemistry 1971; Japan Science and Technology Agency
• ISSN: 0525-1931
• DOI: 10.2116/bunsekikagaku.20.327

The reaction mixture of chloranil and aniline gives absorption maxima at 390 mμ and 540 mμ in the visible region. The former had been ascribed to the absorption of 2, 5-dianilino-3, 6-dichloro-p-benzoquinone(I) and the latter to the charge transfer complex compound of aniline and chloranil. The authors isolated 2-anilino-3, 5, 6-trichloro-1, 4-benzoquinone(II) from the reaction mixture of chloranil and aniline as purple crystals, which was identified by comparison of its melting point, visible and infrared absorption spectra with those of an authentic sample which was synthesized according to the literature. II had an absorption maximum at 550 mμ, and it was suggested that the absorption maximum at 540 mμ of the reaction mixture was due at least partly to II. The resolution of the absorption curve of the reaction mixture by a curve resolver showed the presense of II and another component which had weak and wide absorption band (λmax 520 mμ), and this component was supposed to be the charge transfer complex compound. The compound I also gave a very slight absorption near this region. Accordingly, it was concluded that the absorption at 540 mμ of the reaction mixture of chloranil and aniline was due mainly to II and partly to the charge transfer compound together with very slight contribution of I.