Self-assembly and phase separation of amphiphilic dyads based on 4,7-bis(2-thienyl) benzothiodiazole and perylene diimide

To get highly ordered organic structures at the nanoscale, a series of new electronic donor-acceptor (D-A) dyads were synthesized. The dyads bearing different side chains (lipophilic or amphiphilic) or linkers (Long or Short) showed variable self-assembly behaviour. Long-linker dyads can fold in dilute solution, but the folding of short-linker dyads was not observed. Intermolecular D-A interactions and acceptor-acceptor (A-A) aggregation were proved to co-occur in chloroform for all four dyads. In the bulk state, amphiphilic dyads could overcome the intrinsic D-A interactions and achieve better D-A phase separation than lipophilic ones due to the incompatibility of the side chains. The dyad with a short-linker and amphiphilic side chains, S-amphi, had the ability to form a gel, and both of the amphiphilic dyads could form nanofibres.