Rhenium(I) and technetium(I) tricarbonyl complexes with phosphoraneimines

[NEt4](2)[Re(CO)(3)Br-3] and [NEt4](2)[Tc(CO)(3)Cl-3] react with trimethylsilyltriphenylphosphoraneimine, Me3SiNPPh3, under exchange of the bromo ligands and the formation of cationic [M(CO)(3)(HNPPh3)(3)](+) complexes (M = Re, Tc). The required protons are abstracted from the solvent CH2Cl2. The steric bulk of the organic ligands causes a marked distortion of the established coordination polyhedra from an idealized octahedron with bond angles between neighbouring donor atoms between 81.81(8)degrees and 96.66(8)degrees. The reaction of [NEt4](2)[Re(CO)(3)Br-3] with Me3SiNP(Ph-2)CH2PPh2 in CH2Cl2 yields the neutral complex [Re(CO)(3)Br{HNP(Ph-2)CH2PPh2)], which contains a neutral, chelate-bonded(diphenylphosphinomethyl)diphenylphosphoraneimine ligand. A similar reaction with the bifunctional phosphoraneimine Me3SiNP(Ph-2)CH2(Ph-2)PNSiMe3 gives only small amounts of a binuclear rhenium(l) complex of the composition [{Re(CO)(3)Br-2}(2)(HNP(Ph-2)CH2(Ph-2)PNH)](2-), whereas the major amount of the bis-phosphoraneimine undergoes an intramolecular rearrangement to yield [H2NP(Ph-2)NP(Ph-2)CH3]Br. An X-ray structure analysis shows a widespread delocalization of electron density over the central part of the cation.