Computational Investigation of Dicyanoisophorone-Based Fluorophores: Substituent and Site Effects

Dicyanoisophorone-based fluorophores (DF) hold broad application prospects in the fields of fluorescent probes and biomedicine. However, the structure-activity relationship (SAR) of these fluorophores following the introduction of different substituents at distinct sites remains unclear, which limits their further application and performance optimization. In this study, we systematically investigated the effects of introducing electron-donating groups (Me, OMe, NH₂, NMe₂ and NPh₂) and electron-withdrawing groups (F, NO₂, COOH, CN and SO₃H) at the C3, C4, and C6 sites of the benzene ring on the structure and properties of DF from a theoretical perspective, thereby providing a theoretical basis and reference for the subsequent modification and improvement of this class of fluorescent probes.