Dual Upconverted and Downconverted Circularly Polarized Luminescence in Donor-Acceptor Assemblies

Through mimicking both the chiral and energy transfer in an artificial self-assembled system, not only was chiral transfer realized but also a dual upconverted and downconverted energy transfer system was created that emit circularly polarized luminescence. The individual chiral π-gelator can self-assemble into a nanofiber exhibiting supramolecular chirality and circularly polarized luminescence (CPL). In the presence of an achiral sensitizer Pd^II octaethylporphyrin derivative, both chirality transfer from chiral gelator to achiral sensitizer and triplet-triplet energy transfer from excited sensitizer to chiral gelator could be realized. Upconverted CPL could be observed through a triplet-triplet annihilation photon upconversion (TTA-UC), while downconverted CPL could be obtained from chirality-transfer-induced emission of the achiral sensitizer. The interplay between chiral energy acceptor and achiral sensitizer promoted the communication of chiral and excited energy information.