1-Pyrazolyl phosphazenes and their complexes with palladium(II) chloride and platinum(II) chloride

Abstract

The chlorophosphazenes (NPCl2)3–6 and the phenylchlorophosphazenes gem-N3P3Ph4Cl2 and gem-N3P3Ph2Cl4 react with pyrazole, 3-methylpyrazole, and 3,5-dimethylpyrazole to give (NPpz2)3–6, [NP(Mepz)2]3–5, [NP(Me2pz)2]3,4, N3P3Ph4(Mepz)2, N3P3Ph4(Me2pz)2, and N3P3Ph2(Me2pz)4. Infrared and nmr spectroscopy show the pyrazolyl group to be an electron-withdrawing substituent on the phosphazene ring, resembling a halogen rather than an amino-group. The pyrazolyl group also acts as a donor through its pyridinic nitrogen atom, both intramolecularly and in the formation of the complexes gem-N3P3Ph4(Me2pz)2•PdCl2, gem-N3P3Ph2(Me2pz)4•PdCl2, N3P3(Me2pz)6•2PdCl2, N3P3(Me2pz)6•2PtCl2, and N3P3(Me2pz)6•3PdCl2. No bonding between the metal and a nitrtogen atom in the ring was detected.