Preparation of aqueous solutions of hypovalent germanium; reactions involving germanium-(ii) and -(iii)

Abstract

Solutions 0.2–0.4 mol dm⁻¹ in Ge^II and 6 mol dm⁻¹ in HCl, generated by reaction of Ge^IV with H₃PO₂, are stable for more than three weeks and can be diluted 200-fold with dilute HCl to give GeCl₄²⁻ preparations that may be handled by conventional techniques; kinetic profiles for the reduction of Fe^III by Ge^II, as catalyzed by Cu^II in this medium, implicate, for the first time, the odd-electron intermediate Ge^III, which is formed from Cu^II and Ge^II (k = 30 M⁻¹ s⁻¹ in 0.50 M HCl) and is consumed by reaction with Fe^III (k = 6 × 10² M⁻¹ s⁻¹).