Electronic spectra and solvatochromic behaviour of some 2-arylhydrazonobenzothiazole derivatives

0584-8539/91$3.00+0.00 g?)1991Pergamon Press

Spmrochimica Acta, Vol. 47A. No. 12. pp. 1790, 1991 Printed in Greal Britain

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SHORT NOTE

Electronic spectra and solvatochromic behaviour of some 2arylhydrazonobenzothiazole derivatives* (Received 1 March 1991;in final form 4 April 1991;accepted 15 April 1991)

The electronic spectra of some hydrazonobenzothiazole derivatives were studied. The spectral bands observed in the UV and visible regions were assigned to the possible electronic transitions. The solvatochromic behaviour of the compounds was investigated by studying their visible spectra in pure and in mixed organic solvents of different polarities. The solvated H-bonded complexes formed between DMF and the ortho- and para-derivatives were investigated. The para-nitro derivative was found to exist in a tautomeric equilibrium between the quinonoid azo- and azomethine structures. A complete manuscript, tables and figures have been deposited with the British Library Document Supply Centre at Boston Spa, Wetherby, West Yorks, LS23 7BQ, U.K. as Supplementary Publication No. SUP 13035 (15 pages). Faculty of Science (Qena), Assiut University, Qena, Egypt

Chemistry Department, Faculty of Science, Assiut University, Assiut, Egypt

MOSTAFAH. ABOUEL-WAFA SAID A. IBRAHIM MOHAMEDA.EL-GAHAMI

* Presented in the 3rd IBN SINA symposium 28-31 Jan. 1991, Aswan, Egypt. 1790