Deoxymercuration in Water-Glycerol Mixtures

Abstract

Tbe deoxymercuration kinetics of 2-methyl-2-methoxy-3-iodomercuripropane (I) and 2-methyl-2-methoxy-3-iodomercuripropan-l-ol (II) were followed spectrophotometrically in water and 50 wt. % water-glycerol. The solubilities of I and II in the two solvents were measured. The kinetic data and solubility measurements allow the calculation of the contributions of the transition state and ground state to deoxymercuration in terms of thermodynamic parameters of transfer, ΔG, ΔH, and ΔS (from water to water-glycerol). The role of the solvent then may be deduced under certain assumptions concerning the role of glycerol as a co-solvent. The effect of solvent structure on I is discussed in terms of the “flickering cluster” model of solvation of hydrocarbons. However, a dissection of the solvent effects on II, an alcohol, leads to the conclusion that no simple model of solvation for II exists.