FUW TRENDS IN SCIENCE & TECHNOLOGY JOURNAL
(A Peer Review Journal)
e–ISSN: 2408–5162; p–ISSN: 2048–5170
keywords: Keto enol tautomerism, Nucleophilicity, Hammett substituent’s constant, N arylsalicylaldimine, Hydrogen bonding
Keto enol tautomerism in some N-arylsalicylaldimine derivatives has been evaluated from spectroscopic data. The effect of substituents on the hydrogen bonded ortho hydroxyl Schiff bases were studied using different p substituents with varying nucleophilicity. The N aryl salicylaldimine derivatives were characterized with elemental analysis, infrared, NMR and UV/Visible spectral data. The Schiff bases exist mainly as the phenol-imine tautomers. However, keto-amine tautomers were observed in methanol which is a protic solvent. The extent of the intra-molecular hydrogen bonding in the Schiff bases was evaluated from Hammett substituents’ constant. There was a positive correlation between the band intensity and the substituents nucleophilicity; and consequently with the basicity of the imine nitrogen.
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