Schäfer Fabian, Mix Andreas, Cati Ninive, Lamm Jan-Hendrik, Neumann Beate, Stammler Hans-Georg, Mitzel Norbert W
Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie (ACS), Centre for Molecular Materials (CM2), Universitätsstr. 25, D-33615 Bielefeld, Germany.
Dalton Trans. 2022 May 10;51(18):7164-7173. doi: 10.1039/d2dt00583b.
The bidentate silicon-based Lewis acid, bis(dimethyl-(trifluoromethylsulfonyl)silylethyl)dimethylsilane, MeSi[(CH)SiMeOTf], was prepared in a two-step synthesis starting from dimethyldivinylsilane by hydrosilylation with dimethylchlorosilane and subsequent Lewis acidity enhancement of the terminal silicon atoms by substituting the chlorine with triflate groups using silver triflate. The potential of the resulting MeSi[(CH)SiMeOTf] for binding of Lewis basic guests was explored in reactions with mono- and bifunctional aromatic nitrogen bases. A 1 : 2-adduct with pyridine and a 2 : 2-adduct with 4,4'-bipyridine was structurally characterised in the solid state. In solution, diffusion NMR spectroscopy revealed the existence of complex dynamic equilibria of oligomers which are formed by the host with bidentate guests. The size of the oligomers is significantly determined by the spatial arrangement of the docking sites within the guests and depends on the host-guest ratio.
双齿硅基路易斯酸双（二甲基-（三氟甲基磺酰基）硅烷基乙基）二甲基硅烷，MeSi[(CH)SiMeOTf]，通过两步合成法制备，以二甲基二乙烯基硅烷为起始原料，先与二甲基氯硅烷进行硅氢化反应，然后用三氟甲磺酸银将末端硅原子上的氯原子用三氟甲磺酸酯基团取代，从而增强路易斯酸性。通过与单官能和双官能芳族氮碱的反应，探索了所得MeSi[(CH)SiMeOTf]与路易斯碱性客体结合的潜力。在固态下对与吡啶形成的1:2加合物和与4,4'-联吡啶形成的2:2加合物进行了结构表征。在溶液中，扩散核磁共振光谱揭示了主体与双齿客体形成的低聚物存在复杂的动态平衡。低聚物的大小很大程度上取决于客体中对接位点的空间排列，并取决于主体-客体比例。
