Al-Aqar, RozaAtahan, AlparslanBenniston, Andrew C.Perks, ThomasWaddell, Paul G.Harriman, Anthony2020-05-012020-05-0120160947-65391521-3765https://doi.org/10.1002/chem.201602155https://hdl.handle.net/20.500.12684/6348Waddell, Paul/0000-0002-7851-7347; AL-AQAR, ROZA ABDULRAZAQ SALIH/0000-0001-9960-1313; Harriman, Anthony/0000-0003-0679-2232; Benniston, Andrew/0000-0001-8878-5014WOS: 000384807600008PubMed: 27597381A compact donor-acceptor molecular dyad has been synthesized by attaching an N,N-dimethylamino fragment to a naphthalic anhydride residue. The dyad shows fluorescence from an intramolecular charge-transfer state (i.e., charge-recombination fluorescence) in solution, with the photo-physical properties being strongly dependent on the solvent polarity. Similar emission is seen for single crystals of the target compound, the molecules being aligned head-to-head, although time-resolved emission profiles display dual-exponential kinetics. A second polymorph with the head-to-tail alignment also gives rise to two lifetimes that differ somewhat from those of the first structure, which are assigned to bulk and surface-bound molecules. Growing the crystal in the presence of Rhodamine B localizes the dye around the surface. Excitation of the crystal is followed by sub-ps exciton migration along the aligned stacks, with occasional crossing to adjacent stacks and trapping at the surface. Rhodamine B present at very low levels acts as the acceptor for excitons entering the surface layer. Crystals embedded in a polyester resin form an artificial light-harvesting antenna able to sensitize an amorphous silicon solar cell.en10.1002/chem.201602155info:eu-repo/semantics/closedAccesselectronic energy transferfluorescencelight harvestingphotophysicspolymorphArticle22431542015429WOS:000384807600008Q1Q1