Department of Inorganic & Physical Chemistry, Indian Institute of Science, Bangalore, 560012, India.
Dalton Trans. 2011 Oct 28;40(40):10592-7. doi: 10.1039/c1dt10584a. Epub 2011 Jul 14.
The synthesis, characterization, and reactivity of a chromium(0) complex bearing an amine-borane moiety (η(6)-C(6)H(5)CH(2)NMe(2)·BH(3))Cr(CO)(3) (2) is reported. Photolysis of complex 2 results in the elimination of a CO ligand followed by the formation of an intramolecular σ-borane complex (η(1)-(η(6)-C(6)H(5)CH(2)NMe(2)·BH(2)-H))Cr(CO)(2) (3). This species was characterized in solution by NMR spectroscopy. Reaction of complex 2 with photochemically generated (OC)(5)Cr(THF) affords a novel homobimetallic σ-borane complex (OC)(3)Cr(η(6)-C(6)H(5)CH(2)NMe(2)·BH(2)-H-Cr(CO)(5)) (4), wherein one of the BH moieties is bound to the chromium center in an η(1)-fashion. The σ-borane complex 4 was isolated in moderate to good yield (72%). The BH(3) fragment in the complexes 3 and 4 are highly dynamic involving exchange of the BH hydrogen bound to the metal with the terminal BH hydrogen atoms. The dynamics has been studied using variable-temperature NMR spectroscopy. Complexes 2 and 4 have been characterized by X-ray crystallography.
报道了一种含有胺硼烷部分（η(6)-C(6)H(5)CH(2)NMe(2)·BH(3))Cr(CO)(3)（2）的铬（0）配合物的合成、表征和反应性。配合物 2 的光解导致 CO 配体的消除，随后形成分子内σ-硼烷配合物（η(1)-(η(6)-C(6)H(5)CH(2)NMe(2)·BH(2)-H))Cr(CO)(2)（3）。该物种通过 NMR 光谱在溶液中进行了表征。配合物 2 与光化学生成的(OC)(5)Cr(THF)反应得到一种新型同双金属σ-硼烷配合物(OC)(3)Cr(η(6)-C(6)H(5)CH(2)NMe(2)·BH(2)-H-Cr(CO)(5))（4），其中一个 BH 部分以η(1)方式与铬中心键合。σ-硼烷配合物 4 以中等至良好的收率（72％）分离出来。复合物 3 和 4 中的 BH(3)片段非常动态，涉及与金属结合的 BH 氢与末端 BH 氢原子之间的交换。使用变温 NMR 光谱研究了动力学。复合物 2 和 4 已通过 X 射线晶体学进行了表征。
