Chloroform-Driven Excited-State Protonation of Pyrene-Dialkylaniline Derivatives Under Visible Light.

The photophysical and photochemical properties of the organic chromophores are predominantly governed by the aromatic core, electron-donating/withdrawing groups, and inter- and intramolecular electrostatic interactions, while alkyl chains contribute marginally due to their weaker inductive effect. To investigate alkyl chain effects, we synthesized 1-pyrene substituted with N,N-dialkylanilines (C2, C6, C10) via Suzuki coupling. Solvatofluorochromic studies revealed a red-shifted fluorescence with increasing solvent polarity, except in chloroform and methanol, attributed to solute-solvent interaction between solvent proton and the nitrogen atom of N,N-dialkylamine.

Rational Synthesis of Highly Stable Dithienopyrrole-Embedded BODIPYs Exhibiting Large Stokes Shift.

A series of dithienopyrrole (DTP) embedded BODIPYs were synthesized and structurally characterized. These BODIPYs have strong absorption in the green region and broad emission in the red region with a large Stokes shift ranging from 3100 to 4200 cm. Interestingly, all three BODIPYs show intramolecular charge transfer interaction (ICT).