SYNTHESIS AND CRYSTAL STRUCTURE OF THE LITHIUMPHOSPHAGUANIDINE Li(THF)NPhC{N(SiMe3)Ph}PC{N(SiMe3)Ph}NP

Abstract
The reaction of Li(THF)2P(SiMe3)2 with PhNCNPh yields the N,N'-silylated product Li(THF)NPhC{N(SiMe3)Ph}PC{N(SiMe3)Ph}NPh (1), the formation of which can be explained by insertion of one diphenylcarbodiimide molecule into each P—Si bond. 1 was characterised spectroscopically and by X-ray structure analysis. The latter shows the presence of a LiN2C2P six-membered ring with the N—SiMe3 groups having a cis arrangement.