Institute of Inorganic and Analytical Chemistry , Friedrich Schiller University Jena , Humboldtstraße 8 , D-07743 Jena , Germany.
Inorg Chem. 2018 Nov 5;57(21):13937-13943. doi: 10.1021/acs.inorgchem.8b02469. Epub 2018 Oct 24.
The reaction of [(MeSi)N-Ae{μ-N(SiMe)}] with 2,2,5,5-tetramethyltetrahydrofuran in pentane yields the mononuclear complexes [(Methf)Ae{N(SiMe)}] (Ae = Mg (1), Ca (2), Sr (3), and Ba (4)) with three-coordinate alkaline-earth metal centers. With increasing radius of the alkaline-earth metal atoms, the N-Ae-N bond angles decrease. These ether adducts significantly enhance the solubility of the bis(trimethylsilyl)amides of the alkaline-earth metals in hydrocarbon solvents. Contrary to the magnesium derivative 1, the heavier congeners dissociate into mononuclear [Ae{N(SiMe)}] and free MeTHF without formation of sparingly soluble dinuclear [(MeSi)N-Ae{μ-N(SiMe)}].
[(MeSi)N-Ae{μ-N(SiMe)}]与 2,2,5,5-四甲基四氢呋喃在戊烷中的反应生成单核配合物[(Methf)Ae{N(SiMe)}]（Ae = Mg（1），Ca（2），Sr（3）和 Ba（4）），其中具有三配位的碱土金属中心。随着碱土金属原子半径的增加，N-Ae-N 键角减小。这些醚加合物显著提高了碱土金属双（三甲基甲硅烷基）酰胺在碳氢溶剂中的溶解度。与镁衍生物 1 相反，较重的同系物在没有形成难溶性双核[(MeSi)N-Ae{μ-N(SiMe)}]的情况下，分解为单核[Ae{N(SiMe)}]和游离的 MeTHF。
