Investigation Of The Reaction Between Dialkylphosphine Oxides And Carbontetrachloride

Abstract

The time dependent formation of intermediates and end products in the reaction between Et₂P(O)H and CCI₄ is analysed using ₃₁P-NMR technique. The various reaction steps are studied separately in order to elucidate the overall mechanism. A key step is the disproportionation of Et₂P(O)H catalysed by Et₂PCl and Et₂P(O)Cl, in a cyclic process, the latter being produced initially by the reaction between Et₂P(O)H and CCl₄. The diethylphosphine formed during disproportionation reacts immediately with CCl₄, driving the reaction through the intermediates. Et₂PCl and Et₂, PCCl₃ which react with Et₂P(O)OH producing Et₂P(O)Cl, (Et₂PO)₂O, and Et₂P(O)CHCl₂, as end products.

The influence of the substituents on rate and product yields was studied with n-propyl, n-butyl, noctyl, and allyl as substituents in the dialkylphosphine oxide.