Dimeric Li[N(SiMe3)2] reacted with the nitriles 4-XC6H4CN (X = H or Me) in diethyl ether-hexane (1:10) to yield dimeric complexes [4-XC6H4C(NSiMe3) 2·Li(NCC6H4X-4)]2 (X = H 1 or Me 2). Complex 2 is dimeric in the solid state with two four-co-ordinated lithium cations bound in a N,N′-bidentate π fashion to one amidine anion (chelating), forming a double diazaallyl lithium bridge, in a monodentate σ fashion to a nitrogen lone pair of a substrate molecule, and monodentate to a nitrogen lone pair of a second amidine anion. In solution, rapid interconversion of the different lithium-amidine bonds (σ to π and vice versa)was observed by means of the NMR chemical shifts.
|Number of pages||4|
|Journal||Journal of the Chemical Society. Dalton Transactions|
|State||Published - 1994|