Germanium Tetra-ethyl, Ge(C₂H₅)₄

The existence of Germanium Tetra-ethyl, Ge(C₂H₅)₄, the properties of which were foretold by Mendeleeff, shows that germanium shares with other metals of the B subgroups the ability to form volatile organo-metallic compounds. It is formed by the interaction of germanic chloride and zinc ethyl in an atmosphere of carbon dioxide:

GeCl₄ + 2Zn(C₂H₅)₂ = Ge(C₂H₅)₄ + 2ZnCl₂,

is separated from the zinc chloride by water, extracted with ether, dried and distilled.

Germanium ethyl is a colourless liquid having a feeble odour like that of leeks; it is immiscible with, and lighter than, water, and boils at 160° C. Its vapour density at 230° C. is 119 (H = 1), which corresponds to a molecular weight of 238. Since the molecular weight corresponding to the formula Ge(C₂H₅)₄ is 188, the molecules are probably associated in the state of vapour. The vapour burns with a yellowish red flame and forms an explosive mixture with oxygen.