Hydrazino and Azo Derivatives

Hydrazinium di-chlorophosphazene, Cl3P=N-N=PCl3, can be made by the Kirsanov reaction (7.498). It is a colourless very hygroscopic solid which is slightly soluble in POCI3, but insoluble in other common solvents. Controlled hydrolysis at low temperature leads to unstable hydrazido-N,N-bis(phosphoryl dichloride) (7.499), but with excess water the products are HCl, H3PO4 and N2H4 (7.500). 

Organophosphinazines, R3P=N-N=CRR, can be prepared from pentaphosphoranes and hydra-zones (7.501), or from diazoalkanes (7.502). 

These compounds are hydrolysed by water to give hydrazones and phosphine oxides (7.503). Alkyl halides add on at the nitrogen atom to produce salts (7.504). 

A phosphine imine diazonium salt is formed when sodium azide is added to a solution of triphenylchlorophosphonium hexachloroantimonate in benzene (7.505). 

Ph3PCP SbCl + NaN3 Ph3P=N-Nj SbCl + NaCl 

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