Environment Sensitive Probes Based on Squaric Acid Scaffolds

Abstract

Environment-sensitive probes are desirable molecules due to their ability to respond to changes in media. These responses can be measured via photophysical properties such as absorbance and emission, as factors such as polarity and viscosity change. In this project, we investigated how functionalized squaric acid scaffolds, specifically with 8-aminoquinoline moieties, would serve as probes measuring changes in the local media. Four squaric acid derivatives were synthesized, however it was found that only the 1,3-disubstituted squaric acid derivative was a probe sensitive to both polarity and viscosity.