Electronic Structures of Tris(dioxolene)chromium and Tris(dithiolene)chromium Complexes of the Electron-Transfer Series [Cr(dioxolene)3]z and [Cr(dithiolene)
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- 作者：Ruta R. Kapre ; Eberhard Bothe ; Thomas Weyhermü ; ller ; Serena DeBeer George ; Nicoleta Muresan ; Karl Wieghardt
- 刊名：Inorganic Chemistry
- 出版年：2007
- 出版时间：September 17, 2007
- 年：2007
- 卷：46
- 期：19
- 页码：7827 - 7839
- 全文大小：412K
- 年卷期：v.46,no.19(September 17, 2007)
- ISSN：1520-510X
文摘
From the reaction mixture of 3,6-di-tert-butylcatechol, H2[3,6Lcat], [CrCl3(thf)3], and NEt3 in CH3CN in the presenceof air, the neutral complex [CrIII(3,6Lsq)3] (S = 0) (1) was isolated. Reduction of 1 with [Co(Cp)2] in CH2Cl2 yieldedmicrocrystals of [Co(Cp)2][CrIII(3,6Lsq)2(3,6Lcat)] (S = 1/2) (2) where (3,6Lsq)1- is the -radical monoanionico-semiquinonate of the catecholate dianion (3,6Lcat)2-. Electrochemistry demonstrated that both species are membersof the electron-transfer series [Cr(3,6LO,O)]z (z = 0, 1-, 2-, 3-). The corresponding tris(benzo-1,2-dithiolato)chromiumcomplex [N(n-Bu)4][CrIII(3,5LS,S)2(3,5LS,S)] (S = 1/2) (3) has also been isolated; (3,5LS,S)2- represents the closed-shelldianion 3,5-di-tert-butylbenzene-1,2-dithiolate(2-), and (3,5LS,S)1- is its monoanionic radical. Complex 3 is amember of the electron-transfer series [Cr(3,5LS,S)3]z (z = 0, 1-, 2-, 3-). It is shown by Cr K-edge and S K-edgeX-ray absorption, UV-vis, and EPR spectroscopies, as well as X-ray crystallography, of 1 and 3 that the oxidationstate of the central Cr ion in each member of both electron-transfer series remains the same (+III) and that allredox processes are ligand-based. These experimental results have been corroborated by broken symmetry densityfunctional theoretical calculations by using the B3LYP functional.