Synthesis and properties of an optically active helical bis-cobaltocenium ion
Synthesis and properties of an optically active helical bis-cobaltocenium ion
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光学活性螺旋双茂钴离子的合成与性质
DOI：
10.1021/ja00061a019
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发表时间：
1993
影响因子：
15
通讯作者：
A. Rheingold
中科院分区：
文献类型：
--
作者：
A. Gilbert;T. J. Katz;W. Geiger;M. Robben;A. Rheingold
合成了光学活性螺旋双茂钴盐 6，以及两种相关的单钴茂盐 19 和 30。通过 X 射线衍射分析了 6 的结构，结果显示金属之间的距离为 8.49 A。通过电化学或用 K(Hg) 还原 6 产生了在 920 nm 附近吸收的物质，但吸收不是间隔跃迁。相反，它源自孤立的 Co(II) 中心。 19 的还原产物证明了这一点，它仅含有一种钴，也在相似的波长（l max = 957 nm）处吸收。光学和 ESR 光谱表明单还原 6 中的不成对电子主要位于钴上，并且双还原 6 本质上是 Co(II)Co(II) 双自由基
The optically active helical bis-cobaltocenium salt 6 is synthesized, as are two related monocobaltocenium salts, 19 and 30. The structure of 6 is analyzed by X-ray diffraction, which shows that the metals are separated by 8.49 A. Reducing 6 either electrochemically or with K(Hg) produces species that absorb near 920 nm, but the absorption is not an intervalence transition. It originates instead from isolated Co(II) centers. This is demonstrated by the reduction product of 19, which has only one cobalt, also absorbing at a similar wavelength (l max =957 nm). The optical and ESR spectra imply that the unpaired electron in monoreduced 6 is largely localized on cobalt and that direduced 6 is essentially a Co(II)Co(II) diradical