The ν2 (A1)/ν5 (E)/ν3 + ν6 (E) band system of H283SiI was investigated using Fourier transform IR spectra recorded from 820 to 1100 cm- 1 at a resoln. of 2.0 × 10- 3 cm- 1. In total, 11,903 transitions were assigned. Addnl. 1466 transitions reaching the v3 = v6 = 1 state were obtained from the ν3 + ν6 - ν6 and ν3 + ν6 - ν3 hot bands near 360 and 590 cm- 1, resp. Moreover, 30 highly accurate CO2 laser sideband transitions of the rQ0 branch of ν5 (J.M. Frye, W. Schupita, and G. Magerl, J. Mol. Spectrosc. 128, 427 (1988)) were implemented in the data set with J max ' spm = 140 and K max ' spm = 21. To adequately reproduce the complex pattern of interacting levels the Hamiltonian employed included 14 off-diagonal terms. These comprise x,y Coriolis ro-vibration resonances, between ν2/ν5, ν2/ν3 + ν6 and ν5/ν3 + ν6, and the anharmonic Fermi resonance between ν5/ν3 + ν6. All these resonances strongly perturb the v2 = 1, v5 = 1, and v3 = v6 = 1 excited states whose rounded deperturbed vibrational term values are 904.5, 941.1, and 953.7 cm- 1, resp. In addn., the Δl = Δk = ± 2 l-resonance was found to be active within the v3 = v6 = 1 state and between v5 = 1 and v3 = v6 = 1; the Δl = ± 2 , Δk = ∓ 1 l-resonance within the v5 = 1 state and between v5 = 1 and v3 = v6 = 1 was established, as well as the Δl = ± 1 , Δk = ∓ 2 α resonance between v2 = 1 and v5 = 1. A std. deviation of the fit, 0.48 × 10- 3 cm- 1, resulted which is ca. three times the estd. precision of exptl. wavenumbers. Improved J-dependent ground state parameters of H3SiI were obtained by fitting 5420 combination differences, σ(fit) = 0.22 × 10- 3 cm- 1.
Canè, E., Villa, M., Tamassia, F., Fusina, L., Bürger, H., Litz, M. (2016). The spectroscopic analysis of the v2 = 1, v5 = 1, and v3 = v6 = 1 infrared vibration system of H3SiI. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, 162, 36-47 [10.1016/j.saa.2016.02.026].
The spectroscopic analysis of the v2 = 1, v5 = 1, and v3 = v6 = 1 infrared vibration system of H3SiI
CANE', ELISABETTA;VILLA, MATTIA;TAMASSIA, FILIPPO;FUSINA, LUCIANO;
2016
Abstract
The ν2 (A1)/ν5 (E)/ν3 + ν6 (E) band system of H283SiI was investigated using Fourier transform IR spectra recorded from 820 to 1100 cm- 1 at a resoln. of 2.0 × 10- 3 cm- 1. In total, 11,903 transitions were assigned. Addnl. 1466 transitions reaching the v3 = v6 = 1 state were obtained from the ν3 + ν6 - ν6 and ν3 + ν6 - ν3 hot bands near 360 and 590 cm- 1, resp. Moreover, 30 highly accurate CO2 laser sideband transitions of the rQ0 branch of ν5 (J.M. Frye, W. Schupita, and G. Magerl, J. Mol. Spectrosc. 128, 427 (1988)) were implemented in the data set with J max ' spm = 140 and K max ' spm = 21. To adequately reproduce the complex pattern of interacting levels the Hamiltonian employed included 14 off-diagonal terms. These comprise x,y Coriolis ro-vibration resonances, between ν2/ν5, ν2/ν3 + ν6 and ν5/ν3 + ν6, and the anharmonic Fermi resonance between ν5/ν3 + ν6. All these resonances strongly perturb the v2 = 1, v5 = 1, and v3 = v6 = 1 excited states whose rounded deperturbed vibrational term values are 904.5, 941.1, and 953.7 cm- 1, resp. In addn., the Δl = Δk = ± 2 l-resonance was found to be active within the v3 = v6 = 1 state and between v5 = 1 and v3 = v6 = 1; the Δl = ± 2 , Δk = ∓ 1 l-resonance within the v5 = 1 state and between v5 = 1 and v3 = v6 = 1 was established, as well as the Δl = ± 1 , Δk = ∓ 2 α resonance between v2 = 1 and v5 = 1. A std. deviation of the fit, 0.48 × 10- 3 cm- 1, resulted which is ca. three times the estd. precision of exptl. wavenumbers. Improved J-dependent ground state parameters of H3SiI were obtained by fitting 5420 combination differences, σ(fit) = 0.22 × 10- 3 cm- 1.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
