Authors: R Rajamohan S Kothai Nayaki M Swaminathan
Publish Date: 2011/04/21
Volume: 40, Issue: 5, Pages: 803-
Abstract
Spectral characteristics of 5amino2mercaptobenzimidazole AMBZ have been investigated in aqueous βcyclodextrin βCDx solutions The absorbance and fluorescence intensity of the neutral and monocationic forms of AMBZ are enhanced due to the formation of an inclusion complex with βCDx The stoichiometry and binding constants of the complex were calculated using the Benesi–Hildebrand equation Formation of an inclusion complex between AMBZ and βCDx was also confirmed by steady state and timeresolved fluorescence spectroscopy FTIR spectral data and SEM images of the solid complex provide supporting evidence for complex formation The effect of acidity on the ground and excited state equilibrium between neutral and monocationic forms of AMBZ was analyzed in aqueous and βCDx environments The ground and excited state acidity constants in βCDx solutions were found to be different from those in aqueous solution Based on these results the structure of the 11 complex is proposed
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