SYNTHESIS AND SPECTROSCOPIC STUDIES OF SCHIFF BASES FROM VARIOUSLY SUBSTITUTED BENZALDHYDES AND 2-AMINOMETHYL PYRIDINE
No Thumbnail Available
Date
2015-01-14
Authors
Shaibu, R. O.
Watkins, M. G.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
ajol.info
Synthesis, spectral characterization, and biological activities of Cobalt (II) complexes of Schiff bases derived from o-vanillin and p-vanillin with 3-aminopyridine
Rafiu O Shaibu, Gareth M Watkins
Ife Journal of Science 21 (1), 27-38, 2019
Two biologically active Schiff base GL1 and GL2 were synthesized in equimolar reaction of 3-aminopyridine with o-vanillin and p-vanillin. The synthesized Schiff bases were reacted with cobalt acetate, cobalt chloride or cobalt chloride with trimethylamine by using a molar ratio of Schiff base: cobalt salt as 2: 1. The characterization of Schiff bases and cobalt complexes was done by UV–visible in methanol, diffused reflectance, FTIR (mid and far), mass spectrometry studies while 1 H NMR and 13 C NMR were used to further characterize the Schiff bases. The FTIR results confirmed the bidentate binding of the Schiff bases with cobalt center after the formation of the complexes. The UV-visible spectra and diffused reflectance spectra data obtained were used to further investigate the electronic structure as well as the properties of Schiff bases and their cobalt complexes. On the basis of the spectral studies, distorted tetrahedral geometry has been assigned for the Co (II) complexes. The antimicrobial activities of the two Schiff bases GL1, GL2 and their cobalt (II) complexes were tested against laboratory isolated Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and one fungus strain, Aspergillus niger. The antimicrobial evaluation demonstrates significant activity of the Schiff bases and the cobalt complexes against the four known human pathogens. The brine shrimps lethality study confirmed that the compounds are concentration and geometry dependent. The studies showed the complexes were higher in biological activity than the corresponding Schiff bases.
View at ajol.info
[PDF] ajol.info
Related articles
All 2 versions
ajol.info
Synthesis and spectroscopic studies of schiff bases from Variously substituted benzaldhydes and 2-aminomethyl pyridine
Rafiu O Shaibu, Gareth M Watkins
Ife Journal of Science 17 (1), 31-39, 2015
Variously substituted hydroxybenzaldimines have been synthesized from the condensation of salicylaldehyde, o-vanillin, p-vanillin or vanillin with 2-aminomethyl pyridine. The compounds were characterized using elemental analyses, FT-IR, UV-vis. The spectroscopic methods showed the Schiff bases exist as a mixture of tautomer. The electronic effects of the variously substituted hydroxybenzaldehydes were examined in methanol and dimethylformamide (DMF). It was observed that the electronic effects of the substituents and solvents influenced the intramolecular hydrogen bonding via the conjugation of the heterocyclic ring or by modifying the capacity of the nitrogen atom from entering into hydrogen bonding.
Description
Keywords
Research Subject Categories::NATURAL SCIENCES::Chemistry::Inorganic chemistry , Substituted Hydroxybenzaldimines, Tautomerism
Citation
Shaibu, R. O., & Watkins, G. M. (2015). Synthesis and spectroscopic studies of schiff bases from Variously substituted benzaldhydes and 2-aminomethyl pyridine. Ife Journal of Science, 17(1), 31-39.