The structure of some 1-arylazo-2-naphthylamines and their N-acetamides deduced from 13C CP/MAS NMR, X-ray crystallography and DFT theoretical calculations

The crystal structure of 1-(30-methylphenylazo)-2-naphthylamine 1 was determined by the X-ray diffraction method. No dynamic disorder was observed in the crystal of 1, and the azo group adopts trans azo conformation with six-membered ring formed by the intramolecular hydrogen bond. In the solid state, 13C CP/MAS NMR spectrum of its acetamide derivative 2 the double signals were found, in opposition to the other two acetamides of 1-arylazo-2-naphthylamines 3 and 4, in which only a simple pattern of resonances was detected. The DFT computations were employed to the conformational analysis of the title azocompounds. q 2004 Elsevier B.V. All rights reserved