Trimethylphosphine as a reactive solvent: synthesis and crystal structure of Ta(PMe3)3(η2-CH2–PMe2)(η2-CH–PMe2) and synthesis of related molybdenum and tungsten compounds

Abstract

Reduction of solutions of the metal halides TaCl₅, MoCl₅, or WCl₆ in pure trimethylphosphine with sodium sand causes smooth stepwise reduction giving Ta(PMe₃)₃(η²-CH₂–PMe₂)(η²-CH–PMe₂), Mo(PMe₃)₅H₂, or W(PMe₃)₄(η²-CH₂–PMe₂)H respectively; the X-ray crystal structure of the tantalum compound shows the presence of the unique Ta(η²-CH–PMe₂) group.