right). Reproduced with permission. The π-stacked scafold has also been expanded to spatially confine donor/acceptor/donor (D/A/D) motifs. Similar to the monomer analogues of DM-B and DM-Bm, DM-BD1 and DM-BD2 also rely on spatially confined donor-acceptor interaction but with two donors within one molecule in a sandwich-like structure (Figure ). The single crystal structures of DM-BD1 and DM-BD2 are shown in Figure . The additional donor is asserted to be helpful in realizing a more parallel D/A alignment, which results in a small ΔEST (0.00 eV for DM-BD1 and -0.07 eV for DM-BD2) and fast kRISC (2.9×10 5 s -1 for DM-BD1 and 3.1×10 5 s -1 for DM-BD2). The torsion angles between the donor and acceptor moieties were determined to be 30 o