| Abstract [eng] |
In this work electronic properties of seven 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) derivatives having different rotating hydrocarbon groups were investigated by density functional theory (DFT). [2,3,4]-ξ extrapolation of 8-vinil-BODIPY (8VBDP) molecule's electronic energy toward basis set limit was carried out using M06-2X, CAM-B3LYP, B3LYP and wB97X D functionals in Dunning's correlation-consistent basis set. It was found that for calculation of vertical excitation energies it is sufficient to use cc-pVDZ basis set, since vertical excitation energies are not affected by basis set size as much as molecular ground-state electronic energy. Ground-state structures were optimized at M06-2X/cc-pVDZ level of theory. Optimized structures were used as input for calculation of excitation energies at the same level of theory. By comparing different compounds it was found that the type of rotating hydrocarbon group has little effect on vertical excitation energy. Potential energy curve scans along dihedral angle between rotating group and BODIPY fragment coordinate were carried out. Shape of these curves revealed that these molecular rotors should not exhibit viscosity-dependent quantum yield and fluorescence lifetime changes. |
