Reactivity of Phosphanylphosphinidene Complex of Tungsten(VI) toward Phosphines: A New Method of Synthesis of catena-Polyphosphorus Ligands

The reactivity of an anionic phosphanylphosphinidene complex of tungsten­(VI), [(2,6-i-Pr2C6H3N)2(Cl)­W­(η2-t-Bu2PP)]­Li·3DME toward PMe3, halogenophosphines, and iodine was investigated. Reaction of the starting complex with Me3P led to formation of a new neutral phosphanylphosphinidene complex, [(2,6-i-Pr2C6H3N)2(Me3P)­W­(η2-t-Bu2PP)]. Reactions with halogenophosphines yielded new catena-phosphorus complexes. From reaction with Ph2PCl and Ph2PBr, a complex with an anionic triphosphorus ligand t-Bu2P–P(−)–PPh2 was isolated. The main product of reaction with PhPCl2 was a tungsten­(VI) complex with a pentaphosphorus ligand, t-Bu2P–P(−)–P­(Ph)–P(−)–P-t-Bu2. Iodine reacted with the starting complex as an electrophile under splitting of the P–P bond in the t-Bu2PP unit to yield [(1,2-η-t-Bu2P–P–P-t-Bu2)­W­(2,6-i-Pr2C6H3N)2Cl], t-Bu2PI, and phosphorus polymers. The molecular structures of the isolated products in the solid state and in solution were established by single crystal X-ray diffraction and NMR spectroscopy.