Lithiierte Phosphanimine. Synthese und Kristallstrukturen von [LiCH 2 PMe 2 NSiMe 3 ] 4 und [LiCMe 2 P( i Pr) 2 NSiMe 3 ] 2

Lithiated Phosphane Imines. Synthesis and Crystal Structures of [LiCH 2 PMe 2 NSiMe 3 ] 4 and [LiCMe 2 P( i Pr) 2 NSiMe 3 ] 2 The title compounds were prepared by the reaction of Me 3 ‐SiNPMe 3 and Me 3 SiNP( i Pr) 3 , respectively, with n ‐Butylli‐thium at 20°C in n ‐hexane solution. They form white, moisture‐ and oxygen‐sensitive crystals, which were characterized by IR spectroscopy and by crystal structure determinations. – [LiCH 2 PMe 2 NSiMe 3 ] 4 ( 1 ) forms a Li 4 tetrahedron, the faces of which are capped with CH 2 groups with average Li‐C distances of 233 and 251 pm, while the nitrogen atoms occupy the corners of the Li 4 tetrahedron. – [LiCMe 2 P( i Pr) 2 N‐SiMe 3 ] 2 ( 2 ) forms molecules of symmetry C 2 in which the lithium atoms have coordination number three by two carbon atoms and one nitrogen atom with Li‐C distances of 215.2 and 237.9 pm and Li‐N of 192.8 pm.