Synthesis of π-conjugated cobaltadithiolene cyclotrimers and significant effects of electrolyte cation and solvent on their electrochemical, optical and magnetic properties†
Synthesis of π-conjugated cobaltadithiolene cyclotrimers and significant effects of electrolyte cation and solvent on their electrochemical, optical and magnetic properties†
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π-共轭钴二硫烯环三聚体的合成以及电解质阳离子和溶剂对其电化学、光学和磁性能的显着影响†
DOI：
10.1039/a803028f
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
K. Aramaki
中科院分区：
文献类型：
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作者：
H. Nishihara;M. Okuno;N. Akimoto;Naho Kogawa;K. Aramaki
通过[Co(η-C5H5)(S2C2H2)]和[Co(η-C5H4Me)(S2C2H2)]在卤酸水溶液中的缩合反应，合成了一类新的含四个稠环芳环的钴环三核配合物[Co3(η-C5H5)3(S6C6)]和[Co3(η-C5H4Me)3(S6C6)]。配合物在非质子介质中经历可逆的三步1e-还原，形成两个混合价状态，总电荷为1-和2-。从氧化还原电势差和从价间转移带评价的核间电子相互作用程度来评价混价络合物的热力学稳定性明显依赖于电解液阳离子的大小和溶剂的极性；更大的阳离子和更多的极性溶剂增加了稳定性和电子相互作用。[Co3(η-C5H5)3(S6C6)]经[Co(η-C5Me5)2]还原后在碳酸亚丙酯(PC)中的电子顺磁共振谱表明，1-和3-物种是顺磁性的，S系数为0.5，而在四氢呋喃中与Na还原形成的3-物种给出了铁磁相互作用的四重态光谱(S系数=0.5)。这是由于四氢呋喃中较小的反离子Na+比PC中的[Co(η-C5Me5)2]+具有更强的静电效应而导致的较弱的核间相互作用。
A new class of cobalt cyclic trinuclear complexes with four fused aromatic rings, [Co3(η-C5H5)3(S6C6)] and [Co3(η-C5H4Me)3(S6C6)], was synthesized by a condensation reaction of [Co(η-C5H5)(S2C2H2)] and [Co(η-C5H4Me)(S2C2H2)], respectively, in aqueous halogenoacid solution. The complexes undergo reversible three-step 1e– reductions in aprotic media forming two mixed-valence states, with overall charges 1– and 2–. The thermodynamic stability of the mixed-valence complexes estimated from the redox potential differences and the degree of internuclear electronic interaction evaluated from the intervalence-transfer bands depends markedly on the size of the electrolyte cation and the solvent polarity; larger cations and more polar solvents increase the stability and the electronic interaction. The EPR spectra of [Co3(η-C5H5)3(S6C6)] reduced by [Co(η-C5Me5)2] in propylene carbonate (pc) indicate that the 1– and 3– species are paramagnetic with S = ½, whereas the 3– species formed by reduction with Na in thf gives a spectrum of the quartet state (S = ) denoting ferromagnetic interaction. This difference is attributed to a weaker internuclear interaction caused by a stronger electrostatic effect of the smaller counter ion, Na+ in thf, compared to [Co(η-C5Me5)2]+ in pc.
M.Okuno、K.Aramaki、H.Nishihara：“模拟风车复合体的比例常数变化，[Cp_3Co_3 (S_6C_6) ] ^<n-> 在混合价态 (n=1,2) 中，通过
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