Chiral Self-Assembly of Nonplanar 10,10′-Dibromo-9,9′-bianthryl Molecules on Ag(111) ShenYixian TianGuo HuangHan HeYanwei XieQiliang SongFei LuYunhao WangPingshan GaoYongli 2017 We report on the low-temperature scanning tunneling microscopy (STM) measurements of the self-assembly of nonplanar 10,10′-dibromo-9,9′-bianthryl (DBBA) molecules on Ag(111) combined with density functional theory (DFT) calculations. DBBA molecules have two enantiomorphous adsorption configurations, from which more chiral structures can be formed. At a low coverage [0.4 monolayer (ML)], DBBA forms racemic netlike islands consisting of molecular chains along ⟨1 2 3̅⟩<sub>Ag</sub>. Moreover, the gliding between the molecular chains gives rise to chiral windmill-like patterns in the islands. At 0.8 ML, DBBA forms a racemic row phase and a homochiral hexamer phase. The molecular appearance difference between the two coexisted phases and the DFT calculated molecular adsorption configuration reveal a decrease in the molecular dihedral angle of DBBA, which implies an enhancement in the intermolecular interactions via CH···π and halogen bonds. The transition from a racemic packing mode to a homochiral one suggests that the suitability of steric configurations is dominant in the close-packing mode under enhanced intermolecular interactions.