Through different pathways, two unsaturated thiolate‐bridged Co^IICo^II complexes [Cp*Co(µ‐SR)₂CoCp*] (1 , R = Ph; 3 , R = i Pr, Cp* = η⁵‐C₅Me₅) were successfully synthesized. Interaction of complexes 1 or 3 with HBF₄ resulted in oxidative addition to give the corresponding thiolate‐bridged Co^IIICo^III hydride bridged complexes 4[BF₄] and 5[BF₄] . ¹H NMR spectroscopic results indicate there exist two conformational isomers after protonation, in which the substituents on the thiolate ligands arranged in a symmetric or unsymmetric geometry. Interestingly, major sym‐4[BF₄] can irreversibly convert into minor unsym‐4[BF₄] at 30 °C evidenced by time‐dependent ¹H NMR spectroscopy. Surprisingly, two isomers of 5[BF₄] remain a dynamic equilibrium from –80 to 30 °C corroborated by variable‐temperature ¹H NMR spectra. Furthermore, these thiolate‐bridged dicobalt hydride complexes are proved to be catalysts for electrocatalytic proton reduction by cyclic voltammetry. Notably, complex 5[BF₄] exhibits better catalytic activity, which highlights the importance of the flexibility of the auxiliary ligand.

中文翻译：

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具有不同取代基的硫氰酸盐-桥联二钴氢化物配合物的合成，异构化和电催化性能

通过不同的途径，两个不饱和硫醇盐桥联钴^II钴^II络合物的[Cp *钴（μ-SR）₂ COCP *]（1，R = Ph值; 3，R =我镨中，Cp * =η ⁵ -C ₅我₅）成功合成。配合物1或3与HBF _4的相互作用导致氧化加成，得到相应的硫醇盐桥接的Co ^III Co ^III氢化物桥接的配合物4 [BF ₄ ]和5 [BF ₄ ]。^1个1 H NMR光谱结果表明质子化后存在两个构象异构体，其中硫醇盐配体上的取代基以对称或不对称的几何结构排列。有趣的是，主要的sym - 4 [BF ₄ ]可以在30°C下不可逆地转化为次要unsym - 4 [BF ₄ ]，这是由时间依赖性¹ H NMR光谱所证明的。令人惊讶的是，5– [BF ₄ ]的两个异构体在–80至30°C的温度范围内保持了动态平衡，并得到了可变温度^1的证实。1 H NMR谱。此外，这些硫醇盐桥接的二钴氢化物络合物被证明是通过循环伏安法还原电催化质子的催化剂。值得注意的是，络合物5 [BF ₄ ]表现出更好的催化活性，这突出了辅助配体的柔性的重要性。