Migratory Insertion of the R sub(2)P Group into a Nitrogen-Nitrogen Bond - A Novel Type of Rearrangement in Phosphorus-Nitrogen Ligand Chemistry. 3. The Rearrangement of Triphosphinohydrazide Ligand -N(PPh sub(2))-N(PPh sub(2)) sub(2) to Triphosphazenide Anion {[(Ph sub(2)P-N] sub(2)PPh sub(2)} super(-) in the Article Options Coordination Sphere of Divalent Cobalt and Nickel

Hydrazine dihydrochloride reacts with 3 equiv of Ph sub(2)PCl in tetrahydrofuran in the presence of triethylamine to give tris(diphenylphosphino)hydrazine (1) in 70% yield. Each nitrogen atom in 1 has a trigonal-planar environment according to X-ray analysis. Thermolysis of 1 at 130 [degrees]C results in the formation of two products: bis(diphenylphosphino)amine and octaphenylcyclotetraphosphazene. The interaction of free ligand 1 with NiBr sub(2) affords a simple adduct [(Ph sub(2)P) sub(2)N-NH-PPh sub(2)]NiBr sub(2), while its anionic (hydrazide) form undergoes rearrangement in a coordination sphere of divalent cobalt and nickel involving migratory insertion of the Ph sub(2)P group into a nitrogen-nitrogen bond. The reaction of 1 with cobalt bis(trimethylsilyl)amide, [(Me sub(3)Si) sub(2)N] sub(2)Co, yields the complex of phosphazenide-type (Me sub(3)Si) sub(2)N-Co[(Ph sub(2)PN) sub(2)PPh sub(2)] (2) in 86% yield. A similar reaction of 1 with nikelocene proceeds with substitution of one Cp ring to form durable 18-electron complex CpNi[(Ph sub(2)PN) sub(2)PPh sub(2)] (3).