Halogen bond-modulated solid-state reordering and symmetry breaking of azahelicenes.

ABSTRACT: Spontaneous symmetry breaking predominately occurs during the aggregation of discrete molecules in solution. Herein, we report a unique solid-state symmetry breaking process of dynamically chiral aza[4]helicenes that emerged in vacuum-driven transformation of halogen bond-woven crystals. Due to the weak feature of the halogen bonding, the halides in the cocrystals can be completely removed under vacuum at an elevated temperature. Interestingly, the aza[4]helicene molecules released from the halogen bond network solely adopt one chiral conformation upon reordering and symmetry breaking instantly occurs in a solid state. The Cotton effects gradually increase with the extension of vacuum-heating treatment, indicating a unidirectional transformation of the chiral conformations and an amplifica

SUBMITTER: Liang J 

PROVIDER: S-EPMC12015230 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature