Treatment of the tricationic gold(III) [Au(MeImCH₂ImMe)₂](PF₆)₃ complex 1-3PF₆ (Im = imidazol-2-ylidene) with excess halides affords complexes 1-3X (X = Cl, Br, and I), resulting from counter anion PF₆⁻/X⁻ exchange. The ¹H chemical shift of the CH₃ groups and particularly that of the CH₂ linker in DMSO-d₆ are different in the three complexes, thus suggesting selective X⋯HC interactions. Complex 1³⁺ can therefore be used as a halide sensor in DMSO and water. The host–guest interaction between the tricationic gold(III) complex and the halides Cl⁻, Br⁻ and I⁻ in solution and in the solid state has been investigated by means of NMR titration experiments, DFT calculations and X-ray structure analysis. The electrostatic interaction between the halides and the triple formal positive charge on the metal centre, together with the CH⋯X hydrogen bonding between the NHC ligand and halides, contributes to the formation of stable supramolecular aggregates in solution and in the solid state. The complexing properties of 1³⁺ are strongly influenced by the nature of the solvent. Formation of the 1 : 1 and 1 : 2 species (1X²⁺ and 1X₂⁺) is observed in DMSO-d₆, while that of only the 1 : 1 aggregates (1X²⁺) is observed in D₂O (X = Cl, Br, and I). Moreover, the selectivity towards the various halides is reversed in the two solvents, being in the order Cl⁻ > Br⁻ > I⁻ in DMSO-d₆ and I⁻ > Br⁻ > Cl⁻ in D₂O. The formation constants of the species 1X²⁺ and 1X₂⁺ in DMSO and 1X²⁺ in water have been determined by fitting the NMR titration curves.

中文翻译：

---

方形平面金（iii）双-（1,1'-二甲基-3,3'-亚甲基-二咪唑-2,2'-二亚甲基）三阳离子作为对卤素阴离子的有效和选择性受体：Au⋯的协同作用X和X⋯HC相互作用†

用过量的卤化物处理三阳离子金（III）[Au（MeImCH ₂ ImMe）₂ ]（PF ₆）_3配合物1-3PF ₆（Im =咪唑-2-亚胺）得到配合物1-3X（X = Cl，Br和I），从抗衡阴离子PF得到₆ ^- / X ^-交换。在这三个配合物中，CH ₃基团的¹ H化学位移，尤其是DMSO-d ₆中CH ₂接头的¹ H化学位移不同，因此表明选择性X⋯HC相互作用。综合大楼1 ³⁺因此可以用作DMSO和水中的卤化物传感器。所述tricationic金（之间的主-客体相互作用III）配合物和卤化物氯^- ，溴^-和我^-在溶液中和在固体状态已经通过NMR滴定实验，DFT计算和X射线结构分析方法研究。卤化物与金属中心的三重形式正电荷之间的静电相互作用，以及NHC配体与卤化物之间的CH⋯X氢键，有助于在溶液和固态下形成稳定的超分子聚集体。1 ³⁺的络合性质受溶剂性质的强烈影响。在DMSO-d _6中观察到1：1和1：2物种（1X ²⁺和1X ₂ ⁺）的形成，而在D ₂ O（X中仅观察到1：1聚集体的形成（1X ²⁺））。= Cl，Br和I）。此外，朝向各种卤化物的选择性反转在两种溶剂中的顺序是C1 ^- >溴^- >我^-在DMSO-d ₆和我^- >溴^- >氯^-在d ₂ O.的形成常数物种1X ²⁺和1X ₂ ⁺在DMSO和1X ²⁺在水已经通过拟合NMR滴定曲线确定。