31P NMR study of the stoichiometry, stability, and thermodynamic data for the complexation of several HgX2: acetylemethylene tripara tolyl phosphorane complexes in various tetrahydrofuran–dimethyl sulfoxide mixtures

Abstract

Hg(II) halides are shown to react with the unsymmetrical phosphorus ylide, CH3COCHP(p-tolyl)3 (Y) to be shaped binuclear products with the composition {HgX2[CH3COCHP(p-tolyl)3(Y)]}2, where X = I, Br, and Cl. 31P NMR measurements were occupied to monitor the stability and stoichiometry of phosphorus ylide complexes with HgX2 in binary tetrahydrofuran–dimethyl sulfoxide mixtures of changing composition. In all instance studied, the change of 31P chemical shift with the [HgX2]/[Y] mole ratio showed the formation of 1:1 complexes. The stable constants of the arising from complexes were appraised from computer fitting of the mole ratio information to an equation that relates the monitored chemical shifts to the stable constant. In all solvent mixtures studied, the stabilities of the consequence 1:1 complexes varied in the order HgI2 < HgBr2 < HgCl2. It was found that, in the instance of all complexes, an addition in the percentage of tetrahydrofuran in the solvent mixtures, consequentially increased the stability of the complexes. The temperature relation formation constants were used for the appraisal of the entropy and enthalpy values for the complexation reaction. It was deduced that in all complexes, the resulting complex enthalpy is made stable and entropy destabilized.