Synthesis and structure of a tris imido phosphonate anion; the missing link in imido analogues of phosphorus oxoanions

The reaction of PCl3 with 3 equivalents of 2-methoxyaniline in THF/NEt3, followed by metallation with (BuLi)-Li-n (2 equivalents) yields a complex [Li2P(H)(NR)(3)](2) 1 (R = 2-methoxyphenyl), whose tris imido phosphonate anion is the imido analogue of the phosphite anion, [HPO3](2-).