A chlorine-free protocol for processing germanium

Replacing molecular chlorine and hydrochloric acid with less energy- and risk-intensive reagents would markedly improve the environmental impact of metal manufacturing at a time when demand for metals is rapidly increasing. We describe a recyclable quinone/catechol redox platform that provides an innovative replacement for elemental chlorine and hydrochloric acid in the conversion of either germanium metal or germanium dioxide to a germanium tetrachloride substitute. Germanium is classified as a “critical” element based on its high dispersion in the environment, growing demand, and lack of suitable substitutes. Our approach replaces the oxidizing capacity of chlorine with molecular oxygen and replaces germanium tetrachloride with an air- and moisture-stable Ge(IV)-catecholate that is kinetically competent for conversion to high-purity germanes.