Solvatochromic Fluorescence Behavior of 8-Aminoquinoline-Benzothiazole: A Sensitive Probe for Water Composition in Binary Aqueous Solutions

Solvatochromic Fluorescence Behavior of 8-Aminoquinoline-Benzothiazole: A Sensitive Probe for Water Composition in Binary Aqueous Solutions

Solvatochromic fluorescence behavior of 8-aminoquinoline based benzothiazole derivative in varying solvent systems has been investigated. Benzothiazole appended 8-aminoquinoline 3 showed distinctive fluorescence color changes depending upon the solvent polarities and the fluorescence color changes occurred over relatively wide span in visible region from 486 nm to 598 nm which can be detected with naked eye. Compound 3 also exhibited significant spectral shifts in ${\lambda}_{em}$ as a function of water composition in binary aqueous solvent systems. The changes are due to the specific interaction of 3 by hydrogen bonding with water as well as general solvent effect. The observed solvatochromic fluorescence characteristics of 3 could be used as a new probe for the micro-environmental polarity changes as well as a sensitive sensor for the determination of water composition in binary aqueous solutions.