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Titre du document / Document title

1H NMR, IR and UV/VIS Spectroscopic Studies of Some Schiff Bases Derived From 2-Aminobenzothiazole and 2-Amino-3-hydroxypyridine

Auteur(s) / Author(s)

ISSA Raafat M. ; KHEDR Abdalla M. ; RIZK Helen ;

Résumé / Abstract

By condensing 2-aminobenzothiazole with 2-hydroxy-l-naphthaldehyde, 2-hydroxybenzaldehyde, 4-methoxybenzaldehyde, 4-hydroxybenzal-dehyde, benzaldehyde and 4-dimethylaminobenzaldehyde, and five Schiff bases la-Ie are prepared. Also, two Schiff bases IIa and IIb are prepared by condensation of 2-amino-3-hydroxypyridine with 2-hydroxy-l-naphthaldehyde and 2-hydroxybenzaldehyde. The 1H NMR, IR and UV/Vis spectra of these seven Schiff bases are investigated. The signals of the 1H NMR spectra as well as the important bands in the IR spectra are considered and discussed in relation to molecular structure. The UV/Vis absorption bands in ethanol are assigned to the corresponding electronic transitions and the electronic absorption spectra of Schiff bases Ib and IIb are studied in organic solvents of different polarities. The UV/Vis absorption spectra of 2-amino-3-hydroxypyridine Schiff bases IIa and IIb are investigated in buffer solutions of different pH values containing 5% (v/v) methanol, and the results are utilized for the determination of pKa and ΔG* of the ionization of the phenolic OH-groups. The fluorescence spectra of IIa and IIb are studied in organic solvents of different polarities. The obtained spectral results are confirmed by some molecular calculations using the atom super position and electron delocalization molecular orbital theory for the Schiff base IIb.

Revue / Journal Title

Journal of the Chinese Chemical Society    ISSN  0009-4536 

Source / Source

2008, vol. 55, no4, pp. 875-884 [10 page(s) (article)]

Langue / Language

Anglais

Editeur / Publisher

Chemical Society, Taipei, TAIWAN, PROVINCE DE CHINE  (1954) (Revue)

Mots-clés d'auteur / Author Keywords

2-Aminobenzothiazole

;

2-Amino-3-hydroxypyridine

;

Benzaldehyde derivatives

;

Schiff bases

;

Spectral studies

;

Molecular orbital calculations

;

Localisation / Location

INIST-CNRS, Cote INIST : 3958, 35400018563602.0240

Nº notice refdoc (ud4) : 20689164



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