The Infrared Absorption Spectrum of Germane

The infrared spectrum of Ge${\mathrm{H}}_4$ has been measured to determine the fundamental vibration frequencies and to investigate the rotational structure of the bands. Intense absorption regions were found, enumerated in the order of their intensities, at 4.74μ (2110 ${\mathrm{cm}}^{-1\mathrm{}}$), 10.7μ (934 ${\mathrm{cm}}^{-1\mathrm{}}$), 3.4μ (2922.7 ${\mathrm{cm}}^{-1\mathrm{}}$ and 3031 ${\mathrm{cm}}^{-1\mathrm{}}$) and 2.3μ (4300 ${\mathrm{cm}}^{-1\mathrm{}}$) which have respectively been identified as ${\nu }_3$, ${\nu }_4$, ${\nu }_1+{\nu }_4$, ${\nu }_3+{\nu }_4$, and $2{\nu }_3$. A much weaker absorption peak near 5.7μ is identified as ${\nu }_2+{\nu }_4$. From the spacings between the principal rotation lines in the fundamentals ${\nu }_3$ and ${\nu }_4$ a value 7.0×${10}^{-40\mathrm{}}$ g-${\mathrm{cm}}^2$ for the moment of inertia of the molecule and values 1.37×${10}^{-8\mathrm{}}$ and 2.06×${10}^{-8\mathrm{}}$ cm, respectively, for the Ge-H and the H-H distances are indicated.