SYNTHESIS OF METHYL-SUBSTITUTED AND DIMETHYL-SUBSTITUTED ETHYLENE DIPHOSPHINE DIOXIDES AND THEIR COMPLEX-FORMING PROPERTIES

Alkylation of diphenylphosphonous acid by allyl bromide leads (depending on the reaction conditions) to the formation of both diphenylallylphosphine oxide and diphenylpropenylphosphine oxide. Addition of phosphonous acids to diphenylpropenylphosphine and diphenyl(2-methyl)propenylphosphine oxides resulted in the formation of a series of methyl- and dimethyl-substituted ethylenediphosphine dioxides. The complex forming ability of diphosphine dioxides with respect to alkali metal cations was studied. It was shown that 1-diphenylphosphinyl-2-methyl-2-dioctylphosphinylpropane (X) has the highest Li/Na selectivity (beta(Li)/beta(Na) = 50).