High-resolution infrared spectroscopy of CH<sub>2</sub>D<sup>79</sup>Br: ro-vibrational analysis of the ν<sub>4</sub> and ν<sub>8</sub> fundamental bands P. Stoppa R. Visinoni A. Baldacci R. Wugt Larsen 10.6084/m9.figshare.4772311.v1 https://tandf.figshare.com/articles/journal_contribution/High-resolution_infrared_spectroscopy_of_CH_sub_2_sub_D_sup_79_sup_Br_ro-vibrational_analysis_of_the_sub_4_sub_and_sub_8_sub_fundamental_bands/4772311 <p>The high-resolution Fourier transform infrared spectrum of CH<sub>2</sub>D<sup>79</sup>Br has been recorded and analysed in the region of the ν<sub>4</sub> and ν<sub>8</sub> fundamentals located in the range 1125−1360 cm<sup>−1</sup>. The strong ν<sub>4</sub> band, centred at 1225 cm<sup>−1</sup>, shows an <i>a</i>/<i>b</i>-hybrid structure with predominant <i>a</i>-type character, whereas ν<sub>8</sub>, at 1253 cm<sup>−1</sup>, generates a <i>c</i>-type contour comparable in intensity to the <i>b</i>-type component of ν<sub>4</sub>. The upper states of these fundamentals are coupled through <i>a</i>- and <i>b</i>-type Coriolis resonances; further complications in this band system arise from perturbations due to the ν<sub>6</sub> = 2 (1183 cm<sup>−1</sup>) and ν<sub>5</sub> = ν<sub>6</sub> = 1 (1359 cm<sup>−1</sup>) dark states. The former interacts with ν<sub>8</sub> = 1 by <i>b</i>-type Coriolis coupling, whereas the latter perturbs the ν<sub>4</sub> = 1 and ν<sub>8</sub> = 1 levels by anharmonic and <i>a</i>-type Coriolis resonances, respectively. Accurate upper state parameters and interaction terms have been determined for the tetrad system ν<sub>4</sub>/ν<sub>8</sub>/2ν<sub>6</sub>/ν<sub>5</sub>+ν<sub>6</sub> by also including in the dataset the assigned transitions of the 2ν<sub>6</sub>−ν<sub>6</sub> and ν<sub>5</sub>+ν<sub>6</sub>−ν<sub>6</sub> hot bands obtained from previous analysis.</p> 2017-03-21 16:48:27 Mono-deuterated methyl bromide infrared spectrum spectroscopic parameters Coriolis interactions