Features of Dismutation of Aryldichlorphosphites

Abstract

The paper considers the spontaneous rearrangement, i.e., dismutation, of phosphorous acid dichlorides (aryl dichlorophosphites) into acid chlorides (diaryl chlorophosphites) with separation of phosphorus trichloride. The starting materials contained phenyl, 1- and 2-naphthols as aromatic radicals. The main patterns of dismutation of aryldichlorophosphites were revealed and the basic factors influencing the process time were determined. The dismutation parameters of aryldichlorophosphites were compared with the regularities revealed earlier for a similar process with the participation of diamidoesters of phosphorous acid containing phenyl and naphthyl substituents as an ether component. Calculations of thermodynamic functions of state, i.e., standard enthalpies of ΔfH0298 formation and S0298 entropies, for the dismutation participants, standard values of the Gibbs energy of ΔrG0298 reactions, were calculated. Calculations were carried out without taking into account the influence of the solvent and for the case of standard conditions, as well as for similar systems --- diamidoesters of phosphorous acid. The calculations allowed us to show the thermodynamic possibility of implementing dismutation of aryl dichlorophosphites at relatively low temperatures. The semi-empirical calculation method (RM1) made it possible to establish the lowest-energy conformations of diaryl chlorophosphites formed as a result of dismutation and show their fundamental difference