Perylene Monoimide as a Versatile Fluoroprobe: The Past, Present, and Future

Perylene dyes have transcended their role as simple colorants and have been reinvigorated as functional dyes. Based on the substitution at the peri-position by six-membered carboxylic imides, the perylene family is principally embellished with perylene diimides (PDIs) and perylene monoimides (PMIs). Perylene dyes are widely acclaimed and adorned on account of their phenomenal thermal, chemical, and photostability juxtaposed with their high absorption coefficient and nearunity fluorescence quantum yield. Although symmetric PDIs have always been in the limelight, their asymmetrical counterpart PMI is already rubbing shoulders, thanks to the consistent efforts of several scientific minds. Recently, there has been an upsurge in engendering PMIbased versatile organic architectures decked with intriguing photophysical properties and pertinent applications. In this review, the synthesis and photophysical features of various PMI-based derivatives along with their relevant applications in the arena of organic photovoltaics, photocatalysis, self-assembly, fluorescence sensing, and bio-imaging are accrued and expounded, hoping to enlighten the less delved but engrossing realm of PMIs.