LAUSR

Abstract Two new BODIPY derivatives (BDP1 and BDP3) were synthetized and characterized using photophysical, electrochemical and theoretical methods. Twisted intramolecular charge transfer (TICT) and intramolecular charge transfer (ICT) phenomena were evidenced from solvatochromism effects in THF/toluene mixtures and supported by theoretical DFT calculations. The different results suggest that TICT and ICT processes are directly related to the meso-alkoxyphenyl and β-ethynylphenolic substitutions linked to the BODIPY core. The functionalization with the β-ethynylphenolic group favors the ICT process due to its coplanarity with the BODIPY moiety, while the functionalization with an alkoxy-phenyl unit, which lacks this coplanarity, exhibited a TICT process instead. The higher electronic conjugation of BDP3 in comparison to BDP1, leads to more pronounced cathodic and anodic shifts. Phenolic moiety has a strong contribution in HOMO orbitals, while LUMO orbital has a contribution for the BODIPY core.