Isolation of Potassium Bis(amido)diazadipnictogenide Salts

The reaction of Zintl phases K₃As₇ and K₃P₇ were investigated with 1-azido-4-bromobenzene (4-BrC₆H₄N₃) and found to yield potassium salts of substituted diazadipnictogen rings (general molecular fragment {(RN)₂Pn₂}; Pn = P, As). In the case of the arsenic derivatives, amido-(imino)-arsenide persists in solution and bis-(amido)-diazadiarsenide persists in the solid state. These two species can be considered to share a monomer-dimer relationship, accessible by alteration between the solid and solution states, whereas in the case of K₃P₇, our crystallographic and spectroscopic studies are consistent with the formation of a bisamido-(bisimino)-diazadiphosphenide, the "dimeric" form, persisting in both the solid and solution phase. Subsequent reactivity studies with amido-(imino)-arsenide show that it can act as a source of amide anion, giving a carbonate and a thiourea derivative when investigated with CO₂ and CS₂, respectively.