THE BENDING VIBRATIONS OF $H_{2}S$

$^{1}$ A. D. Sprague and H. H. Nielsen. J. Chem. Phys. 5, 85 (1937) $^{2}$ R. H. Noble, thesis, The Ohio State University (1946) $^{3}$ H. C. Allen and P. C. Cross, J. Chem. Phys. 19, 140 (1951) $^{4}$ R. H. Noble and H. H. Nielsen, J. Chem. Phys. 18, 667 (1950) $^{1}$ H. R. Grady, P. C. Cross, and G. W. King. Phys. Rev. 75, 1450 (1949)Author Institution: Michigan State College, East Lansing MichiganAbsorption of infrared radiation by hydrogen sulfide has been found to occur between 1050 and $1170 cm^{-1}$. This has been measured on a high-resolution prism-grating spectrograph using a plane grating with 3600 lines per inch. Absorption has previously been $measured^{1,2}$ between 1189 and $1450 cm^{-1}$. These data have been analyzed as the P and R branches of the $\nu_{2}$ (bending) fundamental vibration of $H_{2}S$. This analysis leads to a value of $1183.52 cm^{-1}$ for the lowest-energy level of the excited vibrational state. The effective moments of inertia are presented in Table 1. They approximate those suggested from an analysis of the R branch $alone.^{3}$ The complete absorption band resembles in its main features the hydrogen sulfide absorption $reported^{2,4}$ between 2220 and $2600 cm^{-1}$. Attentative analysis of this region as $2\nu_{2}$ yields a value of about $2355 cm^{-1}$ for the lowest energy level of this state and the moments of inertia listed in Table 1. This analysis was complicated by carbon dioxide absorption which masked the band center, and will be repeated when better data are available. Using the approximation for the reciprocals of inertia: $A_{vi} = A_{e} - \Sigma \varpropto \alpha_{*}{*} (V_{i} + 1/2)$ with similar relations for $B_{vi}$ and $C_{vi}$, and using $A_{e}$, etc., as the values [FIGURE] associated with an equilibrium configuration, we have sufficient information to determine the equilibrium moments and the coefficients $\alpha_{v}$. We were aided in this by analyses of combination bands previously $reported.^{1}$ It is a pleasure to express my gratitude to Dr. H. H. Nielsen and his co-workers at The Ohio State University for the use of a high-resolution spectrograph