Torquato Nicole A, Palasz Joseph M, Bertrand Quentin C, Brunner Felix M, Chan Thomas, Gembicky Milan, Mrse Anthony A, Kubiak Clifford P
Department of Chemistry and Biochemistry, University of California, San Diego 9500 Gilman Dr La Jolla CA 92093 USA
Department of Chemistry, Yale University New Haven CT 06520 USA.
Chem Sci. 2022 Sep 5;13(38):11382-11387. doi: 10.1039/d2sc04042e. eCollection 2022 Oct 5.
Treatment of the trichlorotin-capped trinuclear nickel cluster, [Ni(dppm)(μ-Cl)(μ-SnCl)], 1, with 4 eq. NaHB(Et) yields a μ-SnH capped trinuclear nickel cluster, [Ni(dppm)(μ-H)(μ-SnH)], 2 [dppm = bis(diphenylphosphino)methane]. Single-crystal X-ray diffraction, nuclear magnetic resonance (NMR) spectroscopy, and computational studies together support that cluster 2 is a divalent tin hydride. Complex 2 displays a wide range of reactivity including oxidative addition of bromoethane across the Sn center. Addition of 1 eq. iodoethane to complex 2 releases H (g) and generates an ethyltin-capped nickel cluster with a μ-iodide, [Ni(dppm)(μ-I)(μ-Sn(CHCH))], 4. Notably, insertion of alkynes into the Sn-H bond of 2 can be achieved addition of 1 eq. 1-hexyne to generate the 1-hexen-2-yl-tin-capped nickel cluster, [Ni(dppm)(μH)(μ-Sn(CH))], 5. Addition of H (g) to 5 regenerates the starting material, 2, and hexane. The formally 44-electron cluster 2 also displays significant redox chemistry with two reversible one-electron oxidations ( = -1.3 V, -0.8 V Fc) and one-electron reduction process ( = -2.7 V Fc) observed by cyclic voltammetry.
用4当量的NaHB(Et)处理三氯锡封端的三核镍簇合物[Ni(dppm)(μ-Cl)(μ-SnCl)]（1），得到一个μ-SnH封端的三核镍簇合物[Ni(dppm)(μ-H)(μ-SnH)]（2）[dppm = 双(二苯基膦基)甲烷]。单晶X射线衍射、核磁共振（NMR）光谱和计算研究共同支持簇合物2是一种二价氢化锡。配合物2表现出广泛的反应活性，包括溴乙烷在Sn中心的氧化加成。向配合物2中加入1当量的碘乙烷会释放出H₂(g)，并生成一个带有μ-碘化物的乙基锡封端的镍簇合物[Ni(dppm)(μ-I)(μ-Sn(C₂H₅))]（4）。值得注意的是，通过加入1当量的1-己炔，炔烃可以插入到2的Sn-H键中，生成1-己烯-2-基锡封端的镍簇合物[Ni(dppm)(μ-H)(μ-Sn(C₆H₁₁))]（5）。向5中加入H₂(g)可使起始原料2和己烷再生。形式上具有44个电子的簇合物2也表现出显著的氧化还原化学性质，通过循环伏安法观察到两个可逆的单电子氧化过程（E¹/² = -1.3 V，-0.8 V vs Fc）和一个单电子还原过程（E¹/² = -2.7 V vs Fc）。
