The Infrared Absorption Spectrum of Silane

The spectrum of silane has been investigated to beyond 13.0{μ}. Bands, enumerated in the order of their intensities, were located at 11.0{μ} (910 cm^-1), 4.6{μ} (2183 cm^-1), 3.17{μ} (3153 cm^-1), 3.23{μ} (3095 cm^-1), 5.5{μ} (1820 cm^-1) and 2.3{μ} (4360 cm^-1). Four of these regions have been investigated under higher dispersion and partially resolved. The spectrum appears quite similar, except for certain details, to that of methane and by analogy the above bands have been identified as ν₄, ν₃, ν₁+ν₄, ν₃+ν₄, 2ν₄ and 2ν₃. From these values one may determine ν₁ which takes the value 2243 cm^-1. By the methods developed by Dennison and Johnston one may determine the moment of inertia which from the most probable value for the spacing between lines takes the value I₀=8.9×10^-40 g cm².