六核钴原子簇化学——Ⅲ.一些含Co_6八面体簇骼的原子簇化合物的合成、结构和电化学性质

The Chemistry of Hexacobalt Cluster Compounds Ⅲ. Syntheses, Structures and Electrochemical Properties of a Series of Hexacobalt Cluster Compounds with Octahedral Co_6 Cores

(R_3P)_(4-n)CoX_n(R=Ph,Et等;X=Cl,Br;n=1,2)与Na_2E_x(E=S,Se;x=1,2)在DMF或DMF/乙醇介质中反应得到了一系列六核钴的原子簇化合物Co_6(μ_3-E)_8(PR_3)_6.这些化合物含有正规的或畸变的Co_6八面簇骼.化合物可以用I_2氧化生成正一价的簇合物而不改变簇骼的几何构型.反过来,正一价的簇合物也可以被苊烯钠还原生成中性的簇合物.本文还研究了这些化合物的电化学性质并提出了氧化还原反应的电子传递过程。

The reaction of (R_3P)_(4-n)CoX_n(R=Ph, Et; X=Cl, Br; n=1, 2) with Na_2E_x (E=S, Se; x=1, 2)in DMF or DMF/EtOH solution gave rise to a series of hexacobalt cluster compounds, Co_6(μ_3-E)_8(PR_3)_6, in high yields. The molecular structures of the compounds consist of regular or distorted Co_6 octahedra. The neutral compounds, Co_6 (μ_3-E)_8(PR_3)_6, can be oxidized by I_2 to form monocationic species with the nnchange of Co_6 octahedral cores, while the monocationic compounds, [Co_6(μ_3-E)_8(PR_3)_6]^+, can be reduced by sodium acenaphthalenide to form neutral species. Electrochemical properties of the compounds in dichloromethane have been studied, and electrontransfer sequences for the compounds have also been desoribed.