Synthesis and structural studies of an (8-quinolyl)amido-lithium complex and its reaction with dimethylsilicone

Treatment of 8-aminoquinoline (AQH(2)) with (BuLi)-Bu-n in diethyl ether af fords {[(AQH)(2)]Li-2(OEt2)}(2) (1). Compound 1 reacts with dimethylsilicon e to yield the lithiated SiMe2-bridged complex, {[(AQ)(2)SiMe2]Li-2(OEt2)}( 2) (2), Compound 2 has also been synthesised by treating 1 with dichlorodim ethylsilane affording {[(AQH)(2)SiMe2] (3), followed by dilithiation. All c omplexes were characterised by spectroscopic and X-ray crystallographic met hods. The X-ray structure of 1 reveals a tetranuclear centrosymmetric dimer ic structure with a Li4N4 step-ladder arrangement. Compound 2 is tetranucle ar with an eight-membered Li4N4 ring with ligands straddling Li atoms at op posing corners of the ring. Compound 3 has a SiMe2 group bridging two 8-ami doquinoline functionalities. (C) 2000 Elsevier Science S.A. All rights rese rved.