Chalcogenide esters as reactive intermediates in selenium and tellurium purifications

Abstract

This paper describes a novel application of chalcogenide esters to purify selenium and tellurium to the 99.999% purity level. The chalcogenide esters were prepared from a variety of source materials which include: crude selenium and tellurium and commercial grade selenium dioxide, tellurium dioxide, and selenous acid. Crude selenium and tellurium were first converted to their respective oxides by treatment with concentrated nitric acid. The oxides were condensed with alcohols or diols to obtain the corresponding esters which, on reduction with hydrazine in organic media, provided high purity elemental selenium and tellurium.