Molecular structure of tetramethylgermane from gas electron diffraction

Abstract The molecular structure of Ge(CH 3 ) 4 has been determined from gas-phase electron diffraction augmented by a normal coordinate analysis. Assuming tetrahedral symmetry for the germanium bond configuration, the following structural parameters are found: r g (GeC) = 1.958 ± 0.004 A, r g (CH) = 1.111 ± 0.003 A and ∠(GeCH) = 110.7 ± 0.2° ( R =4.0%). The methyl torsional barrier V 0 is estimated to be 1.3 kJ mol −1 on the basis of an effective angle of torsion 23.0 ± 1.5°, from the staggered form, yielded directly by the analysis. The GeC bond length of Ge(CH 3 ) 4 is the same, within experimental error, as that of Ge(C 6 H 5 ) 4 and is in agreement with the prediction of a modified Schomaker-Stevenson relationship.