Tuning Uranium-Nitrogen Multiple Bond Formation with Ancillary Siloxide Ligands
Tuning Uranium-Nitrogen Multiple Bond Formation with Ancillary Siloxide Ligands
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DOI：
10.1021/ja405815b
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发表时间：
2013-08-14
影响因子：
15
通讯作者：
Mazzanti, Marinello
中科院分区：
文献类型：
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作者：
Camp, Clement;Pecaut, Jacques;Mazzanti, Marinello
用KC8还原[U(OSi((OBu)- bu -t)(3))(4)] 3，产率为69%，制得新型同感物U（III）硅氧化物[K-(18c6)][U(OSi((OBu)- bu -t)(3))] 2。中性的U（III）硅氧化物配合物[U(OSi((OBu)-Bu-t)(3))(2)(mu-OSi((OBu)-Bu-t)(3))](2) 1与金刚烷酰叠氮化物反应，分离出二元U（VI）亚胺配合物[U(2)(NAd)(4)(OSi((OBu)-Bu-t)(3))(4)] 4。x射线晶体结构显示两个[U(NAd)(2)]（2+）基团之间存在“阳离子-阳离子相互作用”。与此相反，2与三甲基硅基和金刚烷基叠氮化物反应得到U(V)亚胺配合物[K(18c6)][U(NSiMe3)(OSi(OBu)-Bu-t)(3))(4)] 5-TMS和[K(18c6)][U(NAd)(OSi(OBu)-Bu-t)(3))(4)] 5-Ad的纯度分别为48%和66%。2与CsN3在-40℃的四氢呋喃中反应生成的混合物，从中分离出叠氮U（IV）配合物[K(18c6)][U(N-3)((OSiOBu)-Bu-t)(3))(4)] 7和mu-氮二铀(V)配合物[KU(mu-N)(OSi((OBu)-Bu-t)(3))](2) 8。8的晶体结构显示了一个罕见的U2N2核的存在，两个氮原子以菱形的几何形状桥接两个铀中心。相比之下，1与CsN3反应生成二铀（IV）配合物Cs{(mu-N)[U(OSi((OBu)-Bu-t)(3)](2)} 9，呈现一个氮配体桥接两个铀和一个铯阳离子。这些结果表明配位环境对U（III）与外体反应结果的重要性。
The new homoleptic ate U(III) siloxide [K-(18c6)][U(OSi((OBu)-Bu-t)(3))(4)] 2 was prepared in 69% yield by reduction of [U(OSi((OBu)-Bu-t)(3))(4)] 3 with KC8. The reaction of the neutral U(III) siloxide complex [U(OSi((OBu)-Bu-t)(3))(2)(mu-OSi((OBu)-Bu-t)(3))](2) 1 with adamantyl azide leads to the isolation of the dinudear U(VI) imido complex [U-2(NAd)(4)(OSi((OBu)-Bu-t)(3))(4)] 4. The X-ray crystal structure shows the presence of a "cation-cation interaction" between the two [U(NAd)(2)](2+) groups. In contrast the reactions of 2 with the trimethylsilyl and adamantyl azides afford the U(V) imido complexes [K(18c6)][U(NSiMe3)(OSi((OBu)-Bu-t)(3))(4)] 5-TMS and [K(18c6)][U(NAd)(OSi((OBu)-Bu-t)(3))(4)] 5-Ad pure in 48% and 66% yield, respectively. The reaction of 2 with CsN3 in THF at -40 degrees C yields a mixture of products from which the azido U(IV) complex [K(18c6)][U(N-3)((OSiOBu)-Bu-t)(3))(4)] 7 and the mu-nitrido diuranium(V) complex [KU(mu-N)(OSi((OBu)-Bu-t)(3))](2) 8 were isolated. The crystal structure of 8 shows the presence of a rare U2N2 core with two nitrido atoms bridging two uranium centers in a diamond-shaped geometry. In contrast, the reaction of 1 with CsN3 affords the diuranium(IV) complex Cs{(mu-N)[U(OSi((OBu)-Bu-t)(3)](2)} 9 presenting a nitrido ligand bridging two uranium and one cesium cations. These results show the importance of the coordination environment in the outcome of the reaction of U(III) with asides.