الفهرس 
ORIGINAL ARTICLEOnly 14 pages are availabe for public view
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Abstract
A number of azo pyrazole derivatives and novel Schiff bases derived from azo diamino pyrazole were synthesized. These included 4-(2-arylhydrazono)-4H-pyrazole-3,5-diamines and N3, N5-dibenzylidene-4-(2-arylhydrazono)-4H-pyrazole-3,5-diamines. The chemical structures of the novel azo dyes were determined using UV–visible, IR, 1H NMR, and 13C NMR spectroscopy. Dye- ing process and tautomerism of the aforementioned azo compounds were predicted using DFT cal- culations. The electronic absorption spectra in methanol were observed and compared to those computed using B3LYP/6-31G(d,p). The dyeing performance of the produced disperse dyes was examined on polyester. The degree of exhaustion and the fastness properties of the dyed samples in terms of washing, perspiration, scorch, and light fastness were assessed. Moreover, the reflectance and color strength of the synthesized dyes were measured and discussed 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license The structures of the isolated products 3a-f were established by their spectroscopic (UV, IR, 1H NMR and 13C NMR) data and elemental analyses. To assign the actual tautomeric and isomeric structure(s) of such products, their spectral data were examined.