Structural investigation on phenyl- and pyridin-2-ylamino(methylene)naphthalen-2(3H)-one. Substituent effects on the NMR chemical shifts
Author(s)
K. Venkatachalam, Taracad
K. Pierens, Gregory
Campitelli, Marc
C. Reutens, David
Griffith University Author(s)
Year published
2010
Metadata
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Schiff bases bearing phenyl and pyridyl groups were synthesized by condensation of appropriate amines with 2-hydroxynaphthaldehyde. These Schiff bases were obtained as colored crystalline solids. The proton NMR spectra of these compounds showed a doublet for the NH protons indicating a keto tautomer for these Schiff bases. The pyridyl-substituted Schiff bases containing hydroxyl moiety were found to show the most downfield shift for the NH protons in DMSO solvent, and this was rationalized due to the formation of a six- and five-membered ring using hydrogen bonds for these two compounds. Correspondingly, the olefinic proton ...
View more >Schiff bases bearing phenyl and pyridyl groups were synthesized by condensation of appropriate amines with 2-hydroxynaphthaldehyde. These Schiff bases were obtained as colored crystalline solids. The proton NMR spectra of these compounds showed a doublet for the NH protons indicating a keto tautomer for these Schiff bases. The pyridyl-substituted Schiff bases containing hydroxyl moiety were found to show the most downfield shift for the NH protons in DMSO solvent, and this was rationalized due to the formation of a six- and five-membered ring using hydrogen bonds for these two compounds. Correspondingly, the olefinic proton of the Schiff bases is also found to be a doublet due to coupling to the amine proton. These Schiff bases exhibited thermochromic properties. Detailed NMR spectral analysis for both the phenyl- and pyridyl-substituted Schiff bases is presented.
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View more >Schiff bases bearing phenyl and pyridyl groups were synthesized by condensation of appropriate amines with 2-hydroxynaphthaldehyde. These Schiff bases were obtained as colored crystalline solids. The proton NMR spectra of these compounds showed a doublet for the NH protons indicating a keto tautomer for these Schiff bases. The pyridyl-substituted Schiff bases containing hydroxyl moiety were found to show the most downfield shift for the NH protons in DMSO solvent, and this was rationalized due to the formation of a six- and five-membered ring using hydrogen bonds for these two compounds. Correspondingly, the olefinic proton of the Schiff bases is also found to be a doublet due to coupling to the amine proton. These Schiff bases exhibited thermochromic properties. Detailed NMR spectral analysis for both the phenyl- and pyridyl-substituted Schiff bases is presented.
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Journal Title
Magnetic Resonance in Chemistry
Volume
48
Issue
8
Subject
Physical Chemistry not elsewhere classified
Medicinal and Biomolecular Chemistry
Physical Chemistry (incl. Structural)