Halogen-Bonded Supramolecular Assemblies Based on Phenylethynyl Pyridine Derivatives: Driving Crystal Packing through Systematic Chemical Modifications

A series of phenylethynyl pyridine derivatives 1−4 possessing both perfluorocarbon (PFC) and hydrocarbon (HC) moieties have been synthesized and used for the formation of halogen bonding (XB)-based networks. X-ray crystal structure analyses indicate the dominance of XB synthons, which represent the one-dimensional (1D) structure directing interaction, leading to the formation of supramolecular chains. The influence of structural/electronic factors (e.g., electron donor/acceptor strength, sterically demanding substituents) on XB formation of compounds 1−4 have been compared with structurally related stilbazole systems (I, II). The XB-bonded networks are formed in collaboration with other noncovalent interactions such as π−π stacking, hydrogen bonding, C−H···F and F···F. Molecular electrostatic potentials and atomic polar tensor (APT) charges of the donor and acceptor sites have been determined by density functional theory (DFT) calculations.

一系列同时携有全氟碳化物（perfluorocarbon, PFC）与碳氢化合物（hydrocarbon, HC）片段的苯乙炔基吡啶衍生物1−4已被成功合成，并用于构建基于卤键（halogen bonding, XB）的网络体系。X射线晶体结构分析结果显示，卤键构筑基元占据主导地位，其作为定向一维（1D）结构的核心相互作用，促成了超分子链的形成。本研究对比了化合物1−4与结构相关的芪唑（stilbazole）体系（I、II）的卤键形成行为，考察了结构/电子因素（如给体/受体强度、位阻型取代基）对化合物1−4卤键形成过程的影响。该卤键键合网络与其他非共价相互作用协同构建而成，包括π-π堆积、氢键、C−H···F以及F···F相互作用。通过密度泛函理论（density functional theory, DFT）计算，我们测定了该体系给体与受体位点的分子静电势以及原子极化张量（APT）电荷。