Molecular and electronic structure of substituted BODIPY dyes: Quantum chemical study

Abstract

Boron dipyrrins, otherwise known as BODIPY, are an actively investigated group of fluorescent dyes. Their main appeal comes from the variance of their spectral properties with substitution. In this work, we focus on a series of different meso-substituted BODIPY dyes. We tested the effect of substituents on the structure and spectroscopic properties of BODIPY. The following substitutes were examined: pentil, 4-dibutylaminophenyl, phenyl, 3,5-dimethylphenyl, 4-hydroxyphenyl, 4-dihydroxyphenyl, 4-carboxyphenyl, 4-dimethylaminophenyl, 4-dibutylaminophenyl, biphenyl, 9-anthryl, 2-thiophenyl and 2-furanyl. At the same time, higher prospects for directional changing in the optical properties of BODIPYs through the addition of aryl groups in position 3 were noted. An investigation of vibrationally-resolved absorption and emission spectra is presented. Subset of compounds was used to compare the most and the least involved (adiabatic hessian and vertical gradient respectively) models and have shown the wider applicability and better accuracy in experimental reproduction of the latter.