The Molecular Structure of Tetramethylgermane Determined by Gas Phase Electron Diffraction

Abstract

. Can. J. Chem. 53,3542 (1975). The molecular structure of tetramethylgermane has been determined by vapor phase electron diffraction. The structural parameters, based on r, interatomic distances are r(GeC) = 1 .945 i 0.003 A, r(CH) = 1.12 _+ 0.02 A, and L(GeCH) = 108 i 2". Tetrahedral symmetry of the GeC4 skeleton was preserved in the analysis by including a shrinkage correction for the C...C interatomic distance. The quoted uncertainties were estimated to include both systematic and random errors.J. LAWRENCE HENCHER et FRANCIS S. MUSTOE. Can. J. Chem. 53,3542 (1975). On a determink la structure molkculaire du tktramkthylgermane par diffraction klectronique en phase vapeur. Les paramktres structuraux, bags sur des distances interatomiques r,, sont r(GeC) = 1.945 i 0.003 A, r(CH) = J .J2 i 0.02 A et L(GeCH) = 108 + 2' . La symktrie tktrakdrique du squelette du GeC4 est maintenue dans I'analyse en faisant intervenir une correction pour le raccourcissement de la distance interatomique C...C. On a estimk les incertitudes rapportks en incluant a la fois les erreurs systkmatiques et les erreurs dus au hasard.[Traduit par le journal]

Heats of formation of GeH4, GeF4 and Ge(CH3)4

“…Two values for the experimental Ge-C bond length in Ge(CH 3 ) 4 are 1.98 Å [52] and a more recent determination of 1.945 Å by Hencher and Mustol [53], who attribute the difference to 40 years of development in the experimental technique. Our bond length, without relativistic correction, is almost in the middle of these two experimental values and is in good agreement with B3LYP/RESC value reported by Lie et al [25].…”

Structure of tetramethyltin, Sn(CH3)4

“…data of Si(CH3) 4 (Brockway & Jenkins, 1936;Sheehan & Schomaker, 1952;Beagley, Monaghan & Hewitt, 1971), Ge(CH3) 4 (Brockway & Jenkins, 1936;Hencher & Mustoe, 1975), Sn(CH3) 4 (Brockway & Jenkins, 1936;Nagashima, Fujii & Kimura, 1973) and Pb(CH3) 4 (Brockway & Jenkins, 1936;Wong & Schomaker, 1958;Oyamada, Iijima & Kimura, 1971) show the molecules to be undistorted tetrahedra in the gaseous state. In the course of investigations on low-temperature rotational tunnelling in the solid state of methyl groups in the series M(CH3) 4 with M = Si, Ge, Sn and Pb, more than one tunnel splitting and other anomalies in the nuclear magnetic resonance and inelastic neutron scattering experiments suggested non-equivalent methyl groups in Sn(CH3) 4 (M/illerWarmuth, Dupr~e & Prager, 1984;Prager, Dupr~e & M/iller-Warmuth, 1983).…”

Molecular mechanics (MM3) study of organogermanes

“…Tetramethylgermane. Electron diffraction 29 was applied to determine the molecular structure of tetramethylgermane, r g value. The methyl barrier was measured as 1.3 kcal mol À1 by far-infrared spectroscopy, 30 which was different from that in an earlier study, 0.65 kcal mol…”