Molecular structure of C(GeBr3)(4) determined by gas-phase electron diffraction and density functional theory calculations: Implications for the length and stability of Ge-C bonds in crystalline semiconductor solids

The structure of C(GeBr3)(4) has been determined by gas-phase electron diffraction. It has a C-Ge bond length of 2.042(8) Angstrom (about 0.1 Angstrom longer than normal), and the 12 Br atom positions are close to the vertices of a regular icosahedron. Density functional calculations closely reproduce the observed structure. The implications of the observed structure for bond lengths in Ge-C crystals and related electronic materials based on the diamond structure are discussed.