Wallach Christoph, Geitner Felix S, Karttunen Antti J, Fässler Thomas F
Department Chemie, Technische Universität München, Lichtenbergstraße 4, 85747, Garching b. München, Germany.
Department of Chemistry and Materials Science, Aalto University, 00076, Aalto, Finland.
Angew Chem Int Ed Engl. 2021 Feb 1;60(5):2648-2653. doi: 10.1002/anie.202012336. Epub 2020 Dec 1.
The unique three-dimensional structure of spherical, homoatomic nine-atom germanium clusters opens various possibilities for the spatial arrangement of functional groups. Ligands comprising lone pairs have recently been introduced in the cluster sphere, and we now report the addition of a boranyl group to the cluster featuring a Ge-B exo-cluster bond. The reaction of the twofold-silylated cluster [Ge {Si(TMS) } ] (TMS=trimethylsilyl) with 2-chloro-1,3,2-diazaborolidines DAB -Cl leads to the first boranyl-functionalized [Ge ] clusters [Ge {Si(TMS) } DAB ] (R=methyl (1 a), iso-propyl (2 a), ortho-tolyl (3 a)). The anions 2 a and 3 a were structurally characterized as [NHC Cu] complexes (NHC =1,3-di(2,6-diisopropylphenyl)imidazolylidine) through single crystal X-ray structure determination. Quantum-chemical calculations manifest the frustrated Lewis pair (FLP) character of the boranyl-functionalized cluster [Ge {Si(TMS) } BCy ] (4 a).
球形同原子九原子锗簇独特的三维结构为官能团的空间排列开辟了多种可能性。最近，包含孤对电子的配体已被引入到簇球中，我们现在报告在具有Ge-B簇外键的簇上添加一个硼烷基团。双硅烷基化簇[Ge{Si(TMS)}]（TMS = 三甲基硅基）与2-氯-1,3,2-二氮杂硼烷DAB-Cl反应，生成首个硼烷基官能化的[Ge]簇[Ge{Si(TMS)}DAB]（R = 甲基(1 a)、异丙基(2 a)、邻甲苯基(3 a)）。通过单晶X射线结构测定，阴离子2 a和3 a被表征为[NHC Cu]配合物（NHC = 1,3-二(2,6-二异丙基苯基)咪唑啉）。量子化学计算表明硼烷基官能化簇[Ge{Si(TMS)}BCy]（4 a）具有受阻路易斯对（FLP）特性。
