Mixed-Valent Ruthenocene-Vinylruthenium Conjugates: Valence Delocalization Despite Chemically Different Redox Sites.
Mixed-Valent Ruthenocene-Vinylruthenium Conjugates: Valence Delocalization Despite Chemically Different Redox Sites.
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DOI：
10.1021/acs.inorgchem.8b03253
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发表时间：
2019-02
影响因子：
4.6
通讯作者：
Christopher Hassenrück;André Mang;R. Winter
中科院分区：
文献类型：
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作者：
Christopher Hassenrück;André Mang;R. Winter
合成了Rc/Rc*-CH═CH-Ru(CO)(L)(PiPr3)2(Rc=(η5-C5H5)Ru(η5-C5H4)；Rc*=(η5-C5Me 5)Ru(η5-C5H4)；L=Cl或κO，O‘-乙酰丙酮酸)，并用循环伏安、红外光谱、UV/Vis/NIR光谱和EPR光谱研究了它们在中性、单一和二氧化状态下的性能。它们对应的自由基阳离子是(几乎)完全离域的混价体系，从它们在近红外(NIR)的低半宽、没有溶致变色、IVCT带的低能量截止以及它们的IR和EPR光谱特征可以看出。电子耦合程度甚至超过了它们的二茂铁类似物，尽管乙烯基Ru和茂金属实体的本征半波电势存在类似的差异，并且茂铁同系物的半波电势分裂要小得多，Δe1/2。所有实验结果都得到了量子化学计算的支持。
Ruthenocene-vinylruthenium conjugates Rc/Rc*-CH═CH-Ru(CO)(L)(P iPr3)2 (Rc = (η5-C5H5)Ru(η5-C5H4); Rc* = (η5-C5Me5)Ru(η5-C5H4); L = Cl or κ O, O' -acetylacetonato) have been prepared and investigated in their neutral, mono-, and dioxidized states by cyclic voltammetry, IR and UV/vis/NIR spectroelectrochemistry, and EPR spectroscopy. Their corresponding radical cations are (almost) completely delocalized mixed-valent systems as indicated by the low half-widths, the absence of solvatochromism, and the low-energy cutoff of their IVCT bands in the near-infrared (NIR) and their IR and EPR spectroscopic signatures. The degree of electronic coupling even exceeds that of their ferrocene analogs despite comparable differences between the intrinsic half-wave potentials of the vinylruthenium and the metallocenyl entities and substantially smaller half-wave potential splittings, Δ E1/2, in the ruthenocene congeners. All experimental results are backed by quantum chemical calculations.