The Structure of the Tetraphenyldithioimidodiphosphinate Ion

Bis(diphenylthiophosphoryl)amine, a weak protic acid, can be readily deprotonated. The alkali salts [Ph2P(S)]2NM have been used to prepare S-bonded complexes with transition metals containing a NP2S2M six membered ring [1]. Although the struc­ tures of the neutral ligand [Ph2P(S)]2NH [2] and of several transition metal complexes [1] have been de­ termined by X-ray diffraction techniques, structures of the alkali salts are still unknown. This also holds for the structure of the free [Ph2P(S)]2N anion. Therefore, no comparison between the various com­ plexes and the free anion can be made.