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

The reactivity of an anionic phosphanylphosphinidene complex of tungsten­(VI), [(2,6-<i>i-</i>Pr₂C₆H₃N)₂(Cl)­W­(η²-<i>t</i>-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>i-</i>Pr₂C₆H₃N)₂(Me₃P)­W­(η²-<i>t-</i>Bu₂PP)]. Reactions with halogenophosphines yielded new <i>catena</i>-phosphorus complexes. From reaction with Ph₂PCl and Ph₂PBr, a complex with an anionic triphosphorus ligand <i>t-</i>Bu₂P–P⁽⁻⁾–PPh₂ was isolated. The main product of reaction with PhPCl₂ was a tungsten­(VI) complex with a pentaphosphorus ligand, <i>t</i>-Bu₂P–P⁽⁻⁾–P­(Ph)–P⁽⁻⁾–P-<i>t</i>-Bu₂. Iodine reacted with the starting complex as an electrophile under splitting of the P–P bond in the <i>t-</i>Bu₂PP unit to yield [(1,2-η-<i>t-</i>Bu₂P–P–P-<i>t-</i>Bu₂)­W­(2,6-<i>i-</i>Pr₂C₆H₃N)₂Cl], <i>t</i>-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