Germanium dichloride dioxane

Germanium dichloride dioxane is a chemical compound with the formula GeCl2(C4H8O2), where C4H8O2 is 1,4-dioxane. It is a white solid. The compound is notable as a source of Ge(II), which contrasts with the pervasiveness of Ge(IV) compounds. This dioxane complex represents a well-behaved form of germanium dichloride.

Synthesis and structure
It is prepared by reduction of a dioxane solution of germanium tetrachloride with tributyltin hydride:
 * GeCl4 + 2 Bu3SnH  +  C4H8O2  ->  GeCl2(O2C4H8)  +  2 Bu3SnCl  +  H2

Hydrosilanes have also been used as reductants.

The complex has a polymeric structure. Germanium adopts an SF4-like shape with cis Cl ligands (Cl-Ge-Cl angle = 94.4°) and axial positions occupied by oxygen provided by a bridging dioxane. The Ge-O and Ge-Cl distances are 2.40 and 2.277 A, respectively.

Reactions
The complex is used in the preparation of organogermanium compounds. In organic synthesis, the complex is used as a Lewis acid with reducing properties.