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) A (about 0.1 A 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.