Actinide hydride complexes as multielectron reductants:: Analogous reduction chemistry from [(C5Me5)2UH]2, [(C5Me5)2UH2]2, and [(C5Me5)2ThH2]2
Actinide hydride complexes as multielectron reductants:: Analogous reduction chemistry from [(C5Me5)2UH]2, [(C5Me5)2UH2]2, and [(C5Me5)2ThH2]2
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DOI：
10.1021/om7003139
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发表时间：
2007-07-02
期刊：
影响因子：
2.8
通讯作者：
Rheingold, Arnold L.
中科院分区：
文献类型：
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作者：
Evans, William J.;Miller, Kevin A.;Rheingold, Arnold L.
已开发出分离[（C5 Me 5）（2）UH]（2）和[（C5 Me 5）（2）UH 2]（2）平衡混合物的组分的方法，从而可以研究它们的还原化学。这些锕系元素的还原剂可以作为四电子、六电子和八电子的还原剂，这取决于底物，其中H-2是H- -> e（-）+（1）/（2）H-2氧化还原对的副产物。这种氢化物还原化学允许无氧化还原活性的Th 4+的络合物如[（C5 Me 5）（2）ThH 2]（2）成为四电子和六电子还原剂。[（C5 Me 5）（2）UH]（2）和[（C5 Me 5）（2）UH 2]（2）干净地还原2当量的PhEEPh（E = S，Se），以在每种情况下以总的四电子还原形成2当量的（C5 Me 5）（2）U（SPh）（2）和（C5 Me 5）（2）U（SePh）（2）。[（C5 Me 5）（2）UH]（2）和[（C5 Me 5）（2）UH 2]（2）还实现3当量的1，3，5，7-环辛四烯的六电子还原为[（C5 Me 5）（C8 H8）U]（2）（C8 H8）和2当量的PhNNPh的八电子还原以形成2当量的U6+亚氨基络合物（C5 Me 5）（2）U（NPh）（2）。在每个反应中，H-2都是副产物。这种基于氢化物的还原用四价氢化钍[（C5 Me 5）（2）ThH 2]（2）也是成功的，其将2当量的PhSSPh还原为（C5 Me 5）（2）Th（SPh）（2），并将3当量的C8 H8还原为[（C5 Me 5）（C8 H8）Th]（2）（C8 H8），同时形成H-2。报告了[（C5 Me 5）（2）UH]（2）、[（C5 Me 5）（2）UH 2]（2）和（C5 Me 5）（2）U（SePh）（2）以及钍还原产物（C5 Me 5）（2）Th（SPh）（2）和[（C5 Me 5）（C8 H8）Th]（2）（C8 H8）的X射线晶体学数据。
Methods to separate the components of the equilibrium mixture of [(C5Me5)(2)UH](2) and [(C5Me5)(2)UH2](2) have been developed that allow their reductive chemistry to be studied. These actinide hydrides can act as four-, six-, and eight-electron reductants depending on the substrate with H-2 as the byproduct of a H- -> e(-) + (1)/(2) H-2 redox couple. This hydride reduction chemistry allows complexes of redox-inactive Th4+ such as [(C5Me5)(2)ThH2](2) to be four- and six-electron reductants. [(C5Me5)(2)UH](2) and [(C5Me5)(2)UH2](2) cleanly reduce 2 equiv of PhEEPh (E = S, Se) to form 2 equiv of (C5Me5)(2)U(SPh)(2) and (C5Me5)(2)U(SePh)(2) in an overall four-electron reduction in each case. [(C5Me5)(2)UH](2) and [(C5Me5)(2)UH2](2) also effect a six-electron reduction of 3 equiv of 1,3,5,7-cyclooctatetraene to [(C5Me5)(C8H8)U](2)(C8H8) and an eight-electron reduction of 2 equiv of PhNNPh to form 2 equiv of the U6+ imido complex (C5Me5)(2)U(NPh)(2). In each reaction, H-2 is a byproduct. This hydride-based reduction is also successful with the tetravalent thorium hydride [(C5Me5)(2)ThH2](2), which reduces 2 equiv of PhSSPh to (C5Me5)(2)Th(SPh)(2) and 3 equiv of C8H8 to [(C5Me5)(C8H8)Th](2)(C8H8) with concomitant formation of H-2. X-ray crystallographic data are reported on [(C5Me5)(2)UH](2), [(C5Me5)(2)UH2](2), and (C5Me5)(2)U(SePh)(2) as well as the thorium reduction products (C5Me5)(2)Th(SPh)(2) and [(C5Me5)(C8H8)Th](2)(C8H8).