Tautocrowns: Aza-15-Crown Moiety Conjugated to a Tautomeric Schiff Base
摘要:
The spectral properties of a tautomeric Schiff base containing aza-15-crown-5 moiety, namely N-((4-methylnaphthalen-1-yl)methylene)-4-(1,4,7,10-tetraoxa-13-azacyclopentadecan-13-yl)aniline on addition of alkali and alkaline earth metal ions were investigated. The newly synthesized ligand exhibited very interesting color changes in presence of metal ions: from yellow (free ligand) via colorlessness (enol tautomer complex) to yellow-orange (keto tautomer complex). These changes result from 2 stepwise processes: complex formation and shift of the tautomeric equilibrium between the tautomers after addition of the metal ions.