THE RELATION BETWEEN THE ABSORPTION SPECTRA AND CHEMICAL CONSTITUTION OF CERTAIN AZO DYES. I. THE EFFECT OF POSITION ISOMERISM ON THE ABSORPTION SPECTRA OF METHYL DERIVATIVES OF BENZENE-AZOPHENOL1,2

1929 ◽  
Vol 51 (4) ◽  
pp. 1204-1213 ◽  
Author(s):  
Wallace R. Brode
Keyword(s):  
Absorption Spectra ◽  
Azo Dyes ◽  
Chemical Constitution ◽  
Methyl Derivatives ◽  
Derivatives Of

Synthesis of some new heterocyclic azo dyes derived from 2-amino-3-cyano4.6-diarylpyridines and investigation of its absorption spectra and stability using the DFT

2020 ◽  
Vol 17 ◽  
Author(s):  
El-sayed M Abdelrehim
Keyword(s):  
Absorption Spectra ◽  
Elemental Analysis ◽  
Azo Dyes ◽  
Absorption Maximum ◽  
Density Functional ◽  
Energy Gap ◽  
Functional Theory ◽  
Mass Spectral ◽  
Chemical Reagents ◽  
Derivatives Of

Introduction: In continuation of our interest of 2-amino-3-cyano-4.6-diarylpyridines reactions in various fields of organic chemistry where we have previously used it in synthesis of many heterocyclic compounds [18-21] and where dyes generally have many applications especially when replacement of benzene or anthraquinone azo dyes with heterocyclic azo dyes so new derivatives of heterocyclic azo dyes derived from 2-amino-3-cyano-4.6-diarylpyridines were prepared. Materials and Methods: The IR spectra (KBr), NMR, elemental microanalyses and mass spectra spectrum, were performed at different faculties of science in Egypt. Absorption spectra were recorded on Unicam SP 750 in DMF and acetone using 1x 10-5 mol l-1 of dye concentration. Optimization was performed using density functional theory (DFT) and time dependent-DFT by applying Becke’s three-parameter hybrid exchange functional with Lee–Yang–Parr gradient-corrected correlation (B3LYP functional). The chemical reagents used in synthesis were purchased from Fluka, Sigma and Aldrich. Result and Discussions: The structure of the preparing Heterocyclic azo dyes is proved using spectroscopic tools and elemental analysis, and investigation of its absorption spectra indicates the effect of both solvent and substituent on absorption maximum. DFT calculations were performed on some the selected dyes. Conclusion: Structures of newly synthesized heterocyclic azo dyes were confirmed using elemental analysis, IR, 1H-NMR, 13CNMR and mass spectral data. DFT theory was used in explaining the electronic properties of the some selected dyes, where the energy gap can help in understanding the reactivity behaviour and stability of these compounds. Absorption spectra indicate the effect of both solvent and substituent on absorption maximum.

Sulphonamides. II. Structure and Tautomerism of Sulphapyridine, Sulphathiazole, and Sulphanilylbenzamidine

1951 ◽  
Vol 4 (1) ◽  
pp. 93 ◽  
Author(s):  
SJ Angyal ◽  
WK Warburton
Keyword(s):  
Absorption Spectra ◽  
Structural Features ◽  
Ultraviolet Absorption ◽  
Amino Group ◽  
Dilute Solution ◽  
Methyl Derivatives ◽  
Derivatives Of

By the study of ultraviolet absorption spectra and comparison with methyl derivatives of known structure it is shown that the two forms of arylsulphonylbenzamidines described by Barber (1943) are tautomers, the more stable one having structure I. In dilute solution, sulphathiazole is found to be mainly X, and sulphapyridine a mixture of XIII and XIV in a ratio which depends on the solvent and can be influenced by changes on the p-amino group. Bands of the spectra are assigned to structural features of these molecules.

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