Design and synthesis of BODIPY based donor-acceptor chromophores

Abstract

The design and synthesis of novel multi-modular π-conjugated donor–acceptor (D–A) chromophores have attracted much attention in the scientific community due to their wide range of applications in organic solar cells (OSCs), organic light-emitting diodes (OLEDs), organic photovoltaics (OPVs), thermally activated delayed fluorescence (TADF) as well as in biological studies.[1–10] The D–A based chromophores which exhibit a high photochemical and thermal stability, broad absorption in the UV-vis region and low HOMO–LUMO gap are the potential candidate for optoelectronic applications.[11] The donor-acceptor technique is one of the useful method for developing NIR absorbing/emitting materials with narrow HOMO–LUMO gap.[12] The optoelectronic properties of the D–A molecules are controlled by the HOMO–LUMO gap, which may be easily tuned by (a) adjusting the π-bridge between donor and acceptor units or (b) choosing the appropriate donor/acceptor unit in the molecular system.[13–16] The donor–acceptor molecular systems consist of an electron-rich donor unit and an electron-poor acceptor unit linked by an appropriate spacer. Using a suitable π-linker (such as a double or triple bond or an aromatic ring), the hybridization of donor and acceptor moieties significantly perturbs the HOMO–LUMO energy levels