(Invited, Digital Presentation) Substituent Effect on Fluorescent Probes: Photophysical- and Electrochemical Properties and Their Application As Chemosensors

Abstract

Stimulus-responsive materials have great potential for sensing applications, and their photophysical- and electrochemical properties can be finely tuned as modifying molecular structure. In this presentation, two series of fluorescent probes, BF2dbm and CzPyr, will be introduced as nitro-explosive and acid chemosensors, respectively. Both series of compounds showed different sensing abilities, varying from electron-withdrawing to electron-donating abilities in the peripheral phenyl groups. The photophysical- and electrochemical properties of these compounds, along with density functional theory and time-dependent density functional theory calculations, are systematically investigated to study the structure-property relationships. For BF2dbm, the emissions in chloroform solution are quenched exponentially by adding o-nitroaniline, with quenching constants up to 17,800 M−1. For CzPyr, an evaluation of the emission properties in the solid-state revealed the photochromic activity, and reversibly switched on and off by controlling the pH conditions.