P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States.
J Am Chem Soc. 2013 Sep 4;135(35):13185-92. doi: 10.1021/ja406610r. Epub 2013 Aug 22.
Thermally stable uranium(VI)-methyl and -acetylide complexes: U(VI)OR[N(SiMe3)2]3 R = -CH3, -C≡CPh were prepared in which coordination of the hydrocarbyl group is directed trans to the uranium-oxo multiple bond. The stability of the uranium-carbon bond is attributed to an inverse trans influence. The hydrocarbyl complexes show greater ITI stabilization than that of structurally related U(VI)OX[N(SiMe3)2]3 (X = F(-), Cl(-), Br(-)) complexes, demonstrated both experimentally and computationally. An inverse trans influence ligand series is presented, developed from a union of theoretical and experimental results and based on correlations between the extent of cis-destabilization, the complexes stabilities toward electrochemical reduction, the thermodynamic driving forces for U═O bond formation, and the calculated destabilization of axial σ* and π* antibonding interactions.
热稳定的六价铀-甲基和 - 乙炔基配合物：U(VI)OR[N(SiMe3)2]3（R = -CH3, -C≡CPh），其中烃基的配位是反式指向铀-氧多重键。铀-碳键的稳定性归因于反式影响的反转。烃基配合物表现出比结构相关的 U(VI)OX[N(SiMe3)2]3（X = F(-), Cl(-), Br(-)）配合物更高的 ITI 稳定化作用，这一点在实验和计算上都得到了证明。提出了一个反式影响配体系列，该系列是理论和实验结果的结合，基于顺式去稳定化的程度、配合物对电化学还原的稳定性、U═O 键形成的热力学驱动力以及轴向 σ* 和 π* 反键相互作用的计算去稳定化之间的相关性。
