The reaction of Re(CO)₅Cl with 4-mercaptopyridine (4-PySH) led to the formation of [Re(CO)₃(4-HPyS)₃]Cl (1), showing three hydrogen-bonding donors of 4-PySH ligands as well as a characteristic ligand-to-metal charge-transfer absorption at ca. 380 nm. In this regard, a variety of anions, i.e., CN^–, OAc^–, F^–, Cl^–, Br^–, I^–, PF₆^–, NO₃^–, ClO₄^–, and H₂PO₄^–, were examined to study anion-recognition studies through hydrogen-bonding functionalities. Upon the addition of CN^– to a methanolic solution of complex 1, a remarkable spectral change with an isosbestic point at ca. 314 nm in the absorption spectra was observed, with a binding constant (K_b) calculated to be 24770 M^–1. Moreover, the OAc^– anion also shows a similar trend, but a mild spectral change, with K_b calculated to be 2170 M^–1. Unlike those of CN^– and OAc^–, the addition of F^–, Cl^–, Br^–, and I^– anions causes a less pronounced spectral change with an isosbestic point at ca. 350 nm and K_b calculated to be 2863–750 M^–1. However, almost no spectral change can be observed for other anions (i.e., PF₆^–, NO₃^–, H₂PO₄^–, and ClO₄^–). Interestingly, the molecular loops of [Re(CO)₃Cl(Py₂S₂)]₂ (2; Py₂S₂ = 4,4′-dipyridyl disulfide) and [Re(CO)₃Cl(Py₂S)_0.35(Py₂S₂)_0.65]₂ (3; Py₂S = 4,4′-dipyridyl sulfide) can be isolated and structurally characterized by X-ray diffraction, where those crystals were grown from diethyl ether diffusion into a methanolic solution of complex 1 with [Bu₄N]CN and [Bu₄N]NO₃, respectively. It is noted that such unusual ligand-coupling reactions toward the homoligand and hybrid-ligand loops of complexes 2 and 3 can be achieved at room temperature in this study.

中文翻译：

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hen（I）4-巯基吡啶化合物及其配体偶联产物的阴离子识别研究

Re（CO）₅ Cl与4-巯基吡啶（4-PySH）的反应导致形成[Re（CO）₃（4-HPyS）₃ ] Cl（1），显示出三个氢键供体的4- PySH配体以及特征性配体到金属的电荷转移吸收约为。380海里 在这一点上，各种阴离子的，即，CN ^-，OAC ^-，F ^- ，氯^- ，溴^- ，我^-，PF ₆ ^-，NO ₃ ^-，CLO ₄ ^- ，和H ₂ PO ₄ ^-进行了研究，以通过氢键功能研究阴离子识别研究。在络合物1的甲醇溶液中添加CN ^–后，光谱的显着变化，等渗点约为ca。在吸收光谱中观察到314 nm，结合常数（K _b）计算为24770 M ^–1。此外，OAC ^-阴离子也显示了类似的趋势，但有轻度的光谱变化，ķ _b计算为2170中号^-1。不像那些CN的^-和OAC ^- ，增加的F ^- ，氯^- ，溴^-和我^–阴离子引起不太明显的光谱变化，等渗点为ca。350 nm和K _b计算为2863–750 M ^–1。然而，几乎没有光谱变化可以为其他阴离子观察（即，PF ₆ ^-，NO ₃ ^-，H ₂ PO ₄ ^- ，和C10 ₄ ^- ）。有趣的是，[Re（CO）₃ Cl（Py ₂ S ₂）] ₂（2 ; Py ₂ S ₂ = 4,4'-二吡啶基二硫化物）和[Re（CO）₃ Cl（Py ₂ S）_0.35（Py ₂ S ₂）_0.65 ] ₂（3 ; Py ₂ S = 4,4'-二吡啶硫醚）可以通过X射线衍射分离和结构表征，其中那些晶体是从乙醚扩散到甲醇溶液中生长的分别具有[Bu ₄ N] CN和[Bu ₄ N] NO _3的配合物1的结构。注意，在这项研究中，可以在室温下实现对配合物2和3的同配体和杂配体环的这种不寻常的配体偶联反应。