The design strategies and applications for organic multi-branched two-photon absorption chromophores with novel cores and branches: a recent review

Although organic multi-branched chromophores (OMBCs) have gained great progress in the fields of two-photon absorption materials, the in-depth study on present OMBCs is still limited to the conventional central cores and branches because the increasing complexity of the OMBCs is paired with an equal increase of the difficulties associated with their syntheses. Very recently, various novel central cores and branches are developed to address these issues and many novel OMBCs are constructed. Therefore, it is necessary to review these advances. Here, the basic molecular structures, two-photon absorption properties, structure–property relationships, heterocyclic branchand two-photon induced fluorescence resonance energy transfer, and the applications in frequency-upconverted photoluminescence, two-photon fluorescence imaging, and two-photon photodynamic therapy are summarized.