Exploring the Effects of Reduction or Lewis Acid Coordination on the U=O Bond of the Uranyl Moiety
Exploring the Effects of Reduction or Lewis Acid Coordination on the U=O Bond of the Uranyl Moiety
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DOI：
10.1021/ic802360y
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发表时间：
2009-04-06
影响因子：
4.6
通讯作者：
Wu, Guang
中科院分区：
文献类型：
--
作者：
Hayton, Trevor W.;Wu, Guang
Li(ArNC(Ph)CHC(Ph)O) ((Ar)acnac；Ar = 2,4,6-Me3C6H2) 或 Na(ArA/C(Ph)CHC(Ph)O) (Ar = 3,5-(Bu2C6H3)-Bu-t) 与 0.5 当量的 UO2Cl2(THF)(3) 反应，形成UO2((Ar)acnac)(2) (Ar = 2,4,6-Me3C6H2,1; 3,5-(Bu2C6H3)-Bu-t, 2)，以橙色结晶固体形式分离，收率良好。 2的结构已通过X射线晶体学证实，而1和2的溶液氧化还原性质已通过循环伏安法测量。配合物 I 在 E-1/2 = -1.52 V（相对于 Fc/Fc(+)）处表现出可逆还原特征，而配合物 2 在 -1.35 V（相对于 Fc/Fc(+)）处表现出还原特征。配合物 1 和 2 与 Cp*Co-2 反应生成 [CP*2Co][UO2((Ar)acnac)(2)] (Ar = 2,4,6-Me3C6H2, 3; 3,5-(Bu2C6H3)-Bu-t, 4)，产率中等至良好。 3和4均已得到充分表征，而4的结构也已通过X射线晶体学确定。 2 与 2 当量的 B(C6F5)(3) 在 CH2Cl2 中反应，分离出 UO(OB{C6F5}(3)) ((Ar)acnac)(2) (Ar = 3,5-(Bu2C6H3)-Bu-t) (5)。原位生成的配合物 5 在 -0.78 V（相对于 Fc/Fc+，100 mV/s 扫描速率）下表现出不可逆还原，这远低于观察到的 2 的还原电位，这与通过 B(C6F5)(3) 配位从铀酰部分去除电子密度一致。
Reaction of Li(ArNC(Ph)CHC(Ph)O) ((Ar)acnac; Ar = 2,4,6-Me3C6H2) or Na(ArA/C(Ph)CHC(Ph)O) (Ar = 3,5-(Bu2C6H3)-Bu-t) with 0.5 equiv of UO2Cl2(THF)(3) results in the formation of UO2((Ar)acnac)(2) (Ar = 2,4,6-Me3C6H2, 1; 3,5-(Bu2C6H3)-Bu-t, 2), which were isolated as orange crystalline solids in good yields. The structure of 2 has been confirmed by X-ray crystallography, while the solution redox properties of 1 and 2 have been measured by cyclic voltammetry. Complex I exhibits a reversible reduction feature at E-1/2 = -1.52 V (vs Fc/Fc(+)), while complex 2 exhibits a reduction feature at -1.35 V (vs Fc/Fc(+)). Complexes 1 and 2 react with Cp*Co-2 to generate [CP*2Co][UO2((Ar)acnac)(2)] (Ar = 2,4,6-Me3C6H2, 3; 3,5-(Bu2C6H3)-Bu-t, 4), in moderate to good yields. Both 3 and 4 have been fully characterized, while the structure of 4 has also been determined by X-ray crystallography. Reaction of 2 with 2 equiv of B(C6F5)(3) in CH2Cl2 leads to the isolation of UO(OB{C6F5}(3)) ((Ar)acnac)(2) (Ar = 3,5-(Bu2C6H3)-Bu-t) (5). Complex 5, generated in situ, exhibits an irreversible reduction at -0.78 V (vs Fc/Fc+, 100 mV/s scan rate) which is considerably lower than the reduction potential observed for 2, consistent with the removal of electron density from the uranyl moiety by coordination of B(C6F5)(3).