Syntheses and structures of an unsolvated tetrakisimidophosphate {Li 3 [P(NBu t ) 3 (NSiMe 3 )]} 2 and the face-sharing double-cubane {Li 2 (THF)[P(O)(NBu t ) 2 (NHBu t )]} 2

The treatment of Me3SiN=P(NHBut)3 with three equivalents of LiBun in toluene produces (Li3(P(NBut)3(NSiMe3)))2 comprised of a Li6N6 cyclic ladder capped on the two hexagonal faces by mu 3-PNSiMe3 groups; the corresponding reaction of O=P(NHBut)3 yields the face-sharing double-cubane (Li2(THF)P(O)(NBut)2(NHBut))2 with a central Li2O2 ring.