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New Alkali Metal Coordinations by Chelating Siloxazane Units within Molecules of the General Formula [X–N–SiMe2–O–SiMe2–N–X]2M4 New solvent free alkali metal amides with Si–O–Si bridges of the general formula [X–N–SiMe2–O–SiMe2–N–X]2M4 (X = tBu ( 1 ), SiMe3 ( 2 ), SiMe2tBu ( 3 ) with M = Li; X = tBu ( 4 ), SiMe3 ( 5 ) with M = Na; X = tBu mit M = K, Li ( 6 )) have been synthesised and characterised by spectroscopic means. X‐ray structure analyses of the six metal derivatives reveal a common structural principle: the four metal atoms within the molecules are incorporated between two molecular halfs and form the bonding links between the two parts. The central molecular skeleton of the molecular halfs consists of a zig‐zag chain N–Si–O–Si–N. This chain is connected to the second one either ideally or approximately by S4 (4) symmetry. The point symmetries within the crystal are either S4 (4) (compounds 2 and 4 ), C2 (2) (compound 6 ), and C1 (1) (compounds 3 and 5 ). Compound 1 is special in different aspects: the molecule has the high crystallographic point symmetry D2d (4m2) and the lithium atoms occupy split atom positions (in a similar way as in compound 2 ). The high symmetry of 1 as well as the split atom positions of the lithium atoms are a consequence of dynamics within the crystal.  相似文献   
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