Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6598481 | Dyes and Pigments | 2018 | 24 Pages |
Abstract
A series of aryl azo derivatives of naphthols (1-3) were studied by means of UV-Vis and NMR spectroscopy in different solvents as well as by quantum chemical calculations and X-ray analysis. Previous studies have shown that Sudan I (1) exists as a tautomeric mixture. The effect of the solvents is minimized by the existing intramolecular hydrogen bond. Therefore, the influence on the tautomeric state in structurally modified 1 has been investigated. Structure 2 contains an additional OH-group, which deprotonates easily and affects the position of the tautomeric equilibrium by changing the electronic properties of the substituent. The implementation of a sidearm in 3 creates a condition for competition between the nitrogen from the azo group and from the piperidine unit for the tautomeric proton. In this case the use of acid as a stimulus for controlling the tautomeric process was achieved.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
S. Hristova, V. Deneva, M. Pittelkow, A. Crochet, F.S. Kamounah, K.M. Fromm, P.E. Hansen, L. Antonov,