ICMol, Department of Inorganic Chemistry, University of Valencia, C/Catedrático José Beltrán 2, 46980 Paterna, Spain.
Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia, 3-13, 50019 Sesto Fiorentino, Italy.
Molecules. 2020 Jul 10;25(14):3155. doi: 10.3390/molecules25143155.
Tetraaza-macrocyclic pyridinophane L-Ts, decorated with a -toluenesulfonyl (tosyl; Ts) group, appear to be a useful tool to provide evidence on how the interplay of various supramolecular forces can help stabilise exotic anionic species such as tribromide (Br) anions. Indeed, crystals of (HL-Ts)(Br)(NO) unexpectedly grew from an acidic (HNO) aqueous solution of L-Ts in the presence of Br anions. The crystal structure of this compound was determined by single crystal XRD analysis. Hydrogen bonds, salt-bridges, anion-, - stacking, and van der Waals interactions contribute to stabilising the crystal lattice. The observation of two independent Br anions stuck over the π-electron densities of pyridine and tosyl ligand groups, one of them being sandwiched between two pyridine rings, corroborates the significance of anion-π interactions for N-containing heterocycles. We show herein the possibility of detecting anion-π contacts from fingerprint plots generated by Hirshfeld surface analysis, demonstrating the effective usage of this structural investigation technique to further dissect individual contributions of stabilising supramolecular forces.
四氮杂大环吡啶并[3,2-b]哒嗪 L-Ts 用对甲苯磺酰基（Ts）基团修饰，似乎是一个有用的工具，可以提供证据证明各种超分子相互作用如何帮助稳定异乎寻常的阴离子物种，如三溴化物（Br）阴离子。事实上，（HL-Ts）（Br）（NO）的晶体是从 L-Ts 的酸性（HNO）水溶液中在 Br 阴离子的存在下意外生长出来的。该化合物的晶体结构通过单晶 XRD 分析确定。氢键、盐桥、阴离子-π 堆积和范德华相互作用有助于稳定晶格。观察到两个独立的 Br 阴离子卡在吡啶和甲苯磺酰基配体基团的π 电子密度上，其中一个夹在两个吡啶环之间，证实了阴离子-π 相互作用对于含氮杂环的重要性。我们在此展示了从由 Hirshfeld 表面分析生成的指纹图中检测阴离子-π 接触的可能性，证明了这种结构研究技术的有效使用，可以进一步剖析稳定超分子相互作用的个别贡献。
