Absorption and fluorescence spectra of new pyrrolo[3,4‐b]quinolizines in condensed phases: A joint experimental and computational study

Abstract

Newly synthesized pyrrolo[3,4‐b]quinolizines, blue‐green to orange‐red in fluorescent dye in solutions and yellow to red fluorescent dyes in solid states, were experimentally and computationally investigated for the electronic and fluorescence spectra in solution as well as in solid state. The solvent effects on the absorption and emission spectra were theoretically investigated by the snapshots‐averaged spectra obtained by the first principle molecular dynamics combined with polarizable continuum model (PCM). Alternatively, the solute–solvent interaction effect on the spectra was examined by fragment molecular orbital‐time dependent density functional theory (FMO‐TDDFT) which considered the explicit solute–solvent interactions. The results indicate that the quantitative prediction limitations of PCM and that the solvatochromic shifts in dichloromethane and ethanol were correctly reproduced by FMO‐TDDFT. The luminescence quantum yields of the compounds were analyzed on the excited state potential surface via the S0/S1‐conical intersections.