Microwave Spectrum and Centrifugal Distortion Effects of H2S

Abstract

The rotational spectrum of ${\mathrm{H}}_2^{32}\mathrm{S}$ in the ground vibrational state has been studied in the 1 cm–0.39 mm wavelength region by means of tunable, high‐resolution microwave spectroscopy. Thirty‐one newly observed rotational transitions of ${\mathrm{H}}_2^{32}\mathrm{S}$ , 12 of which occur at frequencies higher than 600 GHz, have been combined with previous microwave measurements on this molecule in a rotation‐distortion analysis of ${\mathrm{H}}_2^{32}\mathrm{S}$ which is based entirely on high precision microwave data. The results for the effective rotational constants and quartic and sextic distortion constants are (in megahertz): $\mathcal{A}\text{= 310\hspace{0.17em}182.24 ± 0.60,}\mathcal{B}\text{= 270\hspace{0.17em}884.05 ± 0.51,}\mathcal{C}{\text{= 141\hspace{0.17em}705.88 ± 0.51, Δ}}_J{\text{= 49.851 ± 0.038, Δ}}_{\mathrm{JK}}{\text{= −159.696 ± 0.069, Δ}}_K{\text{= 111.851 ± 0.068, δ}}_J{\text{= −6.0191 ± 0.0050, δ}}_K{\text{= 262.17 ± 0.21, H}}_J{\text{= (2.813 ± 0.105) × 10}}^{\text{−2}}{\mathrm{,\; H}}_{\mathrm{JK}}{\text{= (−2.283 ± 0.027) × 10}}^{\text{−1}}{\mathrm{,\; H}}_{\mathrm{KJ}}{\text{= (4.59 ± 0.16) × 10}}^{\text{−1}}{\mathrm{,\; H}}_K{\text{= (−2.765 ± 0.141) × 10}}^{\text{−1}}{\mathrm{,\; h}}_J{\text{= (−5.841 ± 0.081) × 10}}^{\text{−3}}{\mathrm{,\; h}}_{\mathrm{JK}}{\text{= (2.428 ± 0.052) × 10}}^{\text{−1}}$ , and $h_K\text{= 2.870 ± 0.039}$ . In addition, a partial set of distortion terms of order P⁸ and P¹⁰ is found to be necessary in the analysis.