Synthesis and Crystal Structures of Three Thioether Functionalized Lithium Silylamides

A series of three lithium silylamides Li2Me2Si(NC6H4-2-SR)(2) (R=Me, Ph, Bu-t) were prepared from the reaction of the corresponding silylamines Me2Si(NH-C6H4-2-SR)(2) with n-butyl lithium. X-ray single crystal structure analyses revealed the formation of dimers [Li-4{Me2Si(NC6H4-2-SR)(2)}(2)] with Si2N4Li4 hetero-adamantane cores. Recrystallisation of [Li-4{Me2Si(NC6H4-2-SMe)(2)}(2)] and [Li-4{Me2Si(NC6H4-2-SPh)(2)}(2)] from diethyl ether led to the formation of the adducts [Li-4(Et2O)(2){Me2Si(NC6H4-2-SMe)(2)}(2)] and [Li-4(Et2O){Me2Si(NC6H4-2-SPh)(2)}(2)]. In the case of the SMe derivative the addition of two diethyl ether molecules led to a rearrangement of the Si2N4Li4 core to give a double decker structure and in contrast the hetero adamantane structure is retained in the diethyl ether adduct of the SPh derivative.