The halogen bond is the attractive interaction between the electrophilic region of ah alogen atom and the nucleophilic region of another molecular entity,e merging as afavorable manner to manipulate supramolecular chirality in self-assemblies.Engineering halogen bonded helical structures remains achallenge due to its sensitivity to solvent polarity and competitive forces like hydrogen bonds.H erein, we report aX•••X (X = Cl, Br,I)type weak halogen bond that induces the formation and evolution of supramolecular helical structures both in solid and solution state.T he p-conjugated phenylalanine derivatives with F, Cl, Br and Is ubstitution selfassembled into 2 1 helical packing driven by hydrogen bond and halogen bond, respectively.The specific molecular geometries of p-conjugated amino acids gave rise to multiple noncovalent forces to stabilizet he X•••X halogen bond with small bond energies ranging from À0.69 to À1.49 kcal mol À1 .H alogen bond induced an opposite helicity compared to the fluorinated species,a ccompanied by the inversed circularly polarized luminescence.

The halogen bond is the attractive interaction between the electrophilic region of ah alogen atom and the nucleophilic region of another molecular entity,e merging as afavorable manner to manipulate supramolecular chirality in self-assemblies.Engineering halogen bonded helical structures remains achallenge due to its sensitivity to solvent polarity and competitive forces like hydrogen bonds.H erein, we report aX•••X (X = Cl, Br,I)type weak halogen bond that induces the formation and evolution of supramolecular helical structures both in solid and solution state.T he p-conjugated phenylalanine derivatives with F, Cl, Br and Is ubstitution selfassembled into 2 1 helical packing driven by hydrogen bond and halogen bond, respectively.The specific molecular geometries of p-conjugated amino acids gave rise to multiple noncovalent forces to stabilizet he X•••X halogen bond with small bond energies ranging from À0.69 to À1.49 kcal mol À1 .H alogen bond induced an opposite helicity compared to the fluorinated species,a ccompanied by the inversed circularly polarized luminescence.