Schüler Philipp, Görls Helmar, Westerhausen Matthias, Krieck Sven
Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Humboldtstraße 8, 07743 Jena, Germany.
Dalton Trans. 2019 Jun 28;48(24):8966-8975. doi: 10.1039/c9dt01426h. Epub 2019 May 30.
The synthesis of the bistrimethylsilylamide complexes of alkali and alkaline-earth metals with bidentate ether and amine bases 1,2-bis(dimethylamino)ethane (tetramethylethylenediamine, tmeda), dimethyl-methoxyethylamine (dmmea), and 1,2-dimethoxyethane (dme) succeeds via addition of these bases to coligand-free complexes or via ligand exchange of thf adducts. The lithium and sodium complexes are mononuclear (exceptions: [(dme)LiN(SiMe)] and [(tmeda)NaN(SiMe)]) whereas the heavier congeners form dinuclear compounds with central four-membered MN rings. The alkaline-earth metal complexes crystallize as mononuclear complexes i.e. as [(L)M{N(SiMe)}] with four-coordinate metal centers or as [(L)M{N(SiMe)}] with six-coordinate metal atoms. Intramolecular steric repulsion leads to distortions such as an asymmetric coordination of L and/or significantly different proximal and distal M-N-Si bond angles.
通过将碱金属和碱土金属的双三甲基硅烷基酰胺配合物与双齿醚和胺碱1,2 - 双（二甲氨基）乙烷（四甲基乙二胺，tmeda）、二甲基 - 甲氧基乙胺（dmmea）以及1,2 - 二甲氧基乙烷（dme）进行反应，可通过将这些碱添加到无共配体的配合物中，或通过四氢呋喃加合物的配体交换来实现其合成。锂和钠的配合物是单核的（例外情况：[(dme)LiN(SiMe)]和[(tmeda)NaN(SiMe)]），而较重的同族元素形成具有中心四元MN环的双核化合物。碱土金属配合物以单核配合物形式结晶，即作为具有四配位金属中心的[(L)M{N(SiMe)}]或具有六配位金属原子的[(L)M{N(SiMe)}]。分子内的空间排斥会导致畸变，例如L的不对称配位和/或近端和远端M - N - Si键角存在显著差异。
