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.