meso-Nitromethyl-Substituted BODIPYs – A new type of water switchable fluorogenic dyes useful for further core modifications

Abstract A two-step synthetic pathway for direct introduction of the nitromethyl functional group at the meso -position of BODIPY core was explored using a number of meso -unsubstituted BODIPY platforms. Spectral properties of the resulting meso -nitromethyl containing BODIPYs was found to be sensitive to the pH change as well as to the presence of water in organic solvents. Meso -nitromethyl group can be used for further modification of the BODIPY core via reduction or condensation reactions. DFT-PCM and TDDFT-PCM calculations correlate well with the experimental data and explain the observed spectral properties.