Designing Threefold π‐Surfaces Through Peripheral Halogenation to Shape Multidirectional Molecular Packing

ABSTRACT Controlling the interaction landscape of threefold π‐surfaces offers a promising strategy for directing multidirectional molecular packing. Triptycene‐tribenzoquinone, with its rigid three‐bladed framework, provides a suitable platform for exploring this concept. Here we report the synthesis of new fluoro‐, bromo‐, and iodo‐substituted triptycene‐tribenzoquinones, which, together with the previously reported chloro‐substituted derivative, constitute the complete series of hexahalogenated triptycene‐tribenzoquinones ( TT X ; X = F, Cl, Br, and I). Using this series, we systematically investigate the effects of peripheral halogenation on their electronic properties and solid‐state molecular packing. All derivatives exhibit reversible three‐step reduction with first reduction potentials comparable to those of the corresponding tetrahalogenated benzoquinones. Increasing halogen size enhances the anisotropy of the electrostatic surface potential, leading to progressively stronger σ‐hole character. Upon crystallization, different packing modes emerge depending on the interplay between the intrinsic threefold π‐surface geometry, halogen size, and σ‐hole character, with TT F , TT Cl , and TT Br , and TT I forming non‐layered packing, layered rectangular 2D sheets, and a porous 3D network, respectively. These results demonstrate that peripheral halogenation reshapes the interaction landscape of threefold π‐surfaces while preserving their intrinsic redox properties, providing a design strategy for organizing molecular building blocks with multidirectional π‐surfaces into desired supramolecular architectures.