Crystalline Inclusion Compounds Constructed through Self-Assembly of Isonicotinic Acid and Thiocyanato Coordination Bridges

The synthesis, crystal structures, inclusion ability, and structural robustness of novel crystalline
inclusion compounds of [Ni(SCN)2(isoH)2]·xG (isoH = isonicotinic acid; G = aromatic guest) are described.
The inclusion compounds are constructed by stacking identical 2D host layers that consist of SCN-, isoH,
and Ni2+ with van der Waals contact separation. In the layer, two types of rectangular cavities (A-type and
B-type) are formed, and the guests are included in the former cavity. The inclusion compounds were
categorized into four stacking modes according to the difference in the stacking mode of the layers. A
systematic investigation of the crystal structures of the 21 inclusion compounds clarified the close relationship
between the molecular structure of the guest and the resultant stacking mode of the layers.

本文详述了一类新型[Ni(SCN)₂(isoH)₂]·xG型晶体包合物（crystalline inclusion compounds）的合成方法、晶体结构、包合性能与结构稳定性，其中isoH为异烟酸（isonicotinic acid），G为芳香客体。该类包合物由完全相同的二维主体层堆叠构成，二维主体层由硫氰酸根（SCN⁻）、异烟酸配体与Ni²⁺组成，层间以范德华（van der Waals）接触间距相隔。在该二维主体层中，形成了A型与B型两种矩形空腔，客体分子被包合于A型空腔内。研究人员依据层堆叠方式的差异，将该类包合物划分为四种堆叠模式。通过对21种该类包合物晶体结构的系统性研究，明确了客体分子结构与最终形成的层堆叠模式之间的紧密关联。