Investigations on The Interactions of Aurintricarboxylic Acid with 18–Crown–6: Analysis of Fluorescence Enhancement

Dr. Tapas Misra

Volume : III, Issue : VIII, August - 2014

Investigations on The Interactions of Aurintricarboxylic Acid with 18–Crown–6: Analysis of Fluorescence Enhancement

Dr. Tapas Misra

Abstract :

The nature of interactions between aurintricarboxylic acid (ATA) and 18-crown-6 (CW) was investigated by measuring steady state absorption quenching spectra and fluorescence enhancement spectra in aqueous medium. 18-crown-6 (CW) is macrocyclic polyethers has an internal nanocavity, a diameter of ca. 2.6-3.2 �. The fluorescence intensity of ATA increases significantly with the increasing concentration of CW producing 1:1 complex formation with association constant K~2.9 x 103 M-1. The absorption studies indicate that a ground state complex is formed between the probe ATA and the host CW in aqueous medium. In the other hand in the previous studies, it has been found that the fluorescence intensity is decreased markedly with increasing the concentration of CW in case of protonated tryptophan (Trp). These anomalous behaviours are discussed here by various spectroscopic techniques.