Synthesis and Spectroscopic Characterization of the First Symmetrically and Nonsymmetrically Substituted Fluorinated Emerald-Green Trannulenes C60F15R3 Soluble in Polar Media and Water

The first water‐soluble C3v‐symmetrical trannulene derivatives of fluorofullerene C60F18 possessing six carboxylic or ammonium ion groups have been synthesized and spectrally characterized. The stability of emerald‐green aqueous solutions of these compounds was investigated. A novel synthetic route was developed for a step‐by‐step derivatization of C60F18 with different organic C–H acids that yielded nonsymmetrically substituted C60F15R2R′ trannulenes. The synthesized trannulenes were loaded with polar carboxylic groups that improved greatly the solubility of these compounds in aqueous media. We showed that four solubilizing COOH groups could be introduced onto the fullerene cage of C60F15R2R′ trannulenes with R substituents and then some additional organic functionality could be attached independently with R′. The R′ substituent might potentially comprise a ligand responsible for selective targeting of the whole trannulene molecule to some specific tissues or intracellular structures. The demonstrated loading of the fluorofullerene core with polar carboxylic or ammonium groups might be considered as an important step towards the design of sophisticated water‐soluble trannulene‐based assembles for biomedical applications. The first water‐soluble C3v‐symmetrical trannulene derivatives of fluorofullerene C60F18 possessing six carboxylic or ammonium ion groups have been synthesized and spectrally characterized.