Amphiphilic Diazapyrenes with Multiple Stimuli-Responsive Properties

A series of amphiphilic diazapyrenes exhibiting switchable fluorescence under the stimulus of mechanical force or water vapor are reported for the first time. Comprehensive studies of their photophysical properties in different states based on UV-Vis absorption, FL emission, FT-IR spectroscopy, and XRD analysis have revealed a stimuli-induced excimer-based sensing mechanism. The relationship between molecular structures and optical responsive properties of these diazapyrene derivatives is illustrated. Moreover, the unique fluorescent, stimuli-responsive behaviors of these diazapyrene compounds in the solid state are used to fabricate sensory films for successively and orthogonally sensing mechanical force and water vapor. In contrast to the well-established knowledge on the transformation between the pyrene monomer and excimer, our study offers valuable information about the unknown diazapyrene excimers and demonstrates their potential applications in biocompatible force sensors, data storage, and humidity sensors.

Automated summary

This study reports a series of amphiphilic diazapyrenes that exhibit switchable fluorescence under mechanical force or water vapor stimulation. Through comprehensive studies of their photophysical properties, a stimuli-induced excimer-based sensing mechanism was revealed, and the relationship between molecular structures and optical responsive properties was illustrated. The unique fluorescent, stimuli-responsive behaviors of these compounds in the solid state were used to create sensory films for sensing mechanical force and water vapor, showing potential applications in biocompatible force sensors, data storage, and humidity sensors.