Preparation of aqueous solutions of hypovalent germanium; reactions involving germanium-(II) and -(III)

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 x 10(2) M-1 s(-1)).