GeCl4

GeCl4, or germanium tetrachloride, is an inorganic compound of germanium and chlorine. It is a colorless, volatile liquid that fumes in air and is highly moisture sensitive. The germanium center is four-coordinate and adopts a tetrahedral geometry (Ge(IV)). GeCl4 forms covalent Ge–Cl bonds and is a relatively strong Lewis acid, readily accepting electron pairs from donors such as solvents and ligands.

GeCl4 is prepared by direct chlorination of germanium metal or lower-valent germanium compounds with chlorine gas. It is also obtainable from chlorinating germanium oxides under appropriate conditions. The compound is typically handled under strictly anhydrous conditions due to its rapid hydrolysis on contact with water.

GeCl4 hydrolyzes readily in water to give germanium dioxide and hydrogen chloride: GeCl4 + 2 H2O → GeO2 + 4 HCl. In moisture-containing environments it forms oxide-containing species as it hydrolyzes.

In terms of applications, GeCl4 is a convenient precursor for the synthesis of organogermanium compounds and for preparing germanium-containing materials, including precursors for semiconductor and polymer chemistry. In organic synthesis, it functions as a Lewis acidic source of Ge(IV) and forms adducts with Lewis bases, enabling various transmetalation and coordination reactions.

Safety: GeCl4 is corrosive and toxic. It fumes in air and reacts violently with water, releasing HCl. It should be handled in a dry, well-ventilated fume hood with appropriate personal protective equipment.