Some Mechanistic Studies of Organotellurium Chemistry

Abstract

The work in this thesis is concerned with the mechanistic study of some organotellurium compounds, especially the diaryl-ditellurides. The effect of visible irradiation on the diaryl ditellurides in solution cantaining alcohol is described. The photoreaction was found to proceed under aerobic conditions via the breaking of the tellurium-tellurium bond, and the production of a free radical species is reported. The final product obtained from the photoreaction, an bis(aryltellurenyl) oxide, does not dissolve in organic solvents. The assignment of tellurium oxygen vibrational modes of these products is also given. The reaction of iodine with diaryl ditellurides through the attack of the tellurium-tellurium bond is described. Evidence is cited for the existence of two species in solution as intermediate products, Ar2,Te2.I2 and Ar2Te2.212, 1:1 and 1:2 complexes respectively, in equilibrium with the reactants. The values of the equilibrium constants for the 1:1 (K1) and 1:2 (K2) adducts show that the main product in the equilibria is the 1:1 adduct. Kinetic investigations give an independently determined value of K2 which is in very good agreement with that obtained from the equilibrium studies...