Reaction of Diphenyl Phosphite with Copper(l1) Salts in Aqueous Solution

Abstract

The reaction of diphenyl phosphite (DPP) with several copper (I1) salts in water at 80°C has been carried out to study the behavior of DPP in aqueous solution. When the molar ratio of copper TO acetate to DPP was changed from 2: 1 'through 1: 1 to 1: 2, the corresponding main reaction product was changed from copper (I1) monophenyl phosphite [3], through phosphoric copper 01 4 to metallic copper, respectively. The variation in pH is perhaps responsible to the formation of different main products. As the reaction proceeded at pH 2, the main reaction product was actually metallic copper, irrespective of the molar ratios involved. The yield went to 63.8% after 24 hr. The yield varied according to the addition of water soluble organic solvent to the reaction system. In 50 vol% aqueous organic solvent system the yield increased in the order: DMF (89: 0%) DMSO (83.0%) ethanol (82.0%) methanol (75.7%) From the pH titration curve of DPP (Fig.3) DPP was found to dissociate in aqueous solution in two steps. Based on these findings it was assumed that DPP exists in aqueous solution in the form of [2], which accounts for the formation mechanism of metallic copper reasonably.