Uranium-Nitrogen Multiple Bonding: The Case of a Four-Coordinate Uranium(VI) Nitridoborate Complex
Uranium-Nitrogen Multiple Bonding: The Case of a Four-Coordinate Uranium(VI) Nitridoborate Complex
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DOI：
10.1021/ja8095812
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发表时间：
2009-04-29
影响因子：
15
通讯作者：
Cummins, Christopher C.
中科院分区：
文献类型：
--
作者：
Fox, Alexander R.;Cummins, Christopher C.
叠氮硼酸盐[N（n-Bu）（4）][（C6 F5）3B（N-3）]（[N（n-Bu）（4）][1]）与三苯胺铀（III）络合物（THF）U的反应（N[t-Bu]Ar）（3）（2）THF =四氢呋喃; Ar = 3，5-Me 2C 6 H3）导致形成顺磁性铀（V）氮硼配合物[N（n-Bu）（4）][（C6 F5）（3）B N U（N[t-Bu]Ar）（3）]（[N（n-Bu）（4）][3]）。[N（n-Bu）（4）][3]的化学氧化是容易的，并提供抗磁性的铀（VI）氮硼配合物（C6 F5）（3）B N U（N[t-Bu]Ar）（3）（3）。[N（n-Bu）（4）][3]和3是铀的第一个氮硼配合物，并通过多核NMR光谱，单晶X射线衍射方法和元素分析进行了表征。[N（n-Bu）（4）][3]和3的X射线晶体结构显示出极短的U N-氮化物距离（分别为1.916（4）埃和1.880（4）埃）。用密度泛函理论计算了截断模型（C6 F5）（3）B N U（N[Me]Ph）（3）的优化结构;对其他几个具有U N多重键的相关配合物进行了类似的计算。基于Nalewajski-Mrozek价指数计算了键的多重性，结果表明3中的U-N-氮相互作用接近于完整的三键.
Reaction of the azidoborate salt [N(n-Bu)(4)][(C6F5)3B(N-3)] ([N(n-Bu)(4)][1]) with the uranium(III) tris(anilide) complex (THF)U(N[t-Bu]Ar)(3) (2; THF = tetrahydrofuran; Ar = 3,5-Me2C6H3) results in formation of the paramagnetic uranium (V) nitridoborate complex [N(n-Bu)(4)][(C6F5)(3)B N U(N[t-Bu]Ar)(3)] ([N(n-Bu)(4)][3]). Chemical oxidation of [N(n-Bu)(4)][3] is facile and provides the diamagnetic uranium(VI) nitridoborate complex (C6F5)(3)B N U(N[t-Bu]Ar)(3) (3). [N(n-Bu)(4)][3] and 3 are the first nitridoborate complexes of uranium and were characterized by multinuclear NMR spectroscopy, single crystal X-ray diffraction methods, and elemental analysis. The X-ray crystal structures of [N(n-Bu)(4)][3] and 3 reveal extremely short U N-nitrido distances (1.916(4) angstrom and 1.880(4) angstrom, respectively). Density functional theory was used to calculate the optimized structure of the truncated model (C6F5)(3)B N U(N[Me]Ph)(3); the procedure was carried out similarly for several other relevant complexes featuring U N multiple bonds. Bond multiplicities based on Nalewajski-Mrozek valence indices were calculated, the results of which suggest that the U N-nitrido interaction in 3 is close to a full triple bond.