Organisch-Chemisches Institut , Heidelberg University , Im Neuenheimer Feld 270 , 69120 Heidelberg , Germany.
J Am Chem Soc. 2019 Mar 20;141(11):4687-4695. doi: 10.1021/jacs.8b13395. Epub 2019 Mar 5.
Reacting (NHC)(cyclopropenyl)gold(I) complexes with cationic gold complexes [(IPr)AuX] afforded extremely reactive allylium-1,1-diido-bridged digold intermediates. We prove the existence and constitution of this structure with FT-ICR-MS/MS, NMR, and UV-vis-NIR experiments and isolated the nucleophilic addition product [(Me)(Ph)(CCHC){Au(IPr)}(SOMe)]NTf with DMSO. Our computational investigation unveiled that the bonding situation of this μ-allylium-1,1-diido digold domain was best described as a three-center-four-electron bond with a π-backbond. The valence orbitals showed extreme delocalization and strong π-interactions between the three centers Au-C-Au. The bridging carbon atom C was best described as trigonal planar sp-hybridized carbon in this structure. Excitation succeeded in UV-vis-NIR measurements with energies as low as near-IR radiation.
与阳离子金配合物[(IPr)AuX]反应的（NHC）（环丙基）金（I）配合物提供了极其反应性的烯丙基-1,1-二碘桥联二金中间体。我们通过 FT-ICR-MS/MS、NMR 和 UV-vis-NIR 实验证明了这种结构的存在和组成，并分离出具有 DMSO 的亲核加成产物[(Me)(Ph)(CCHC){Au(IPr)}(SOMe)]NTf。我们的计算研究表明，这种μ-烯丙基-1,1-二碘二金结构域的键合情况最好描述为具有π-backbond 的三中心四电子键。价轨道表现出极端的离域和三个中心 Au-C-Au 之间的强π相互作用。在这种结构中，桥接碳原子 C 最好被描述为三角平面 sp 杂化的碳原子。激发在 UV-vis-NIR 测量中成功，能量低至近红外辐射。
