| 1. |
- Wugt Larsen, René, et al.
(författare)
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The equilibrium structure of trans-glyoxal from experimental rotational constants and calculated vibration-rotation interaction constants
- 2003
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Ingår i: Physical Chemistry Chemical Physics. - : Royal Society of Chemistry (RSC). - 1463-9084. ; 5:22, s. 5031-5037
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Tidskriftsartikel (refereegranskat)abstract
- A total of six high-resolution FT-IR spectra for trans-glyoxal-d(2), trans-glyoxal-d(1) and trans-glyoxal-C-13(2) were recorded with a resolution ranging from 0.003 to 0.004 cm(-1). By means of a simultaneous ground state combination difference analysis for each of these isotopologues using the Watson Hamiltonian in A-reduction and I-r-representation the ground state rotational constants are obtained. An empirical equilibrium structure is determined for trans-glyoxal using these experimental ground state rotational constants and vibration - rotation interaction constants calculated at the CCSD(T)/cc-pVTZ level of theory. The least-squares fit yields the following structural parameters for trans-glyoxal: r(e)(C-C) = 1.51453(38) Angstrom, r(e)(C-H) = 1.10071(26) Angstrom, re(C= O) = 1.20450(27) Angstrom, alpha(e)(CCH) = 115.251(24) degrees, and alpha(e)(HCO) = 123.472(19)degrees in excellent agreement with theoretical predictions at the CCSD(T)/cc-pVQZ level of theory.
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| 3. |
- Hegelund, F, et al.
(författare)
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High-Resolution Infrared and Microwave Study of the n20 and n21 Levels near 300 cm-1 in 1,2,4-Triazine.
- 2003
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Ingår i: Journal of Molecular Spectroscopy. - 0022-2852. ; 217:1, s. 9-18
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Tidskriftsartikel (refereegranskat)abstract
- The gas phase far-IR spectrum of the small nu, Greek20 (A″, 367.88 cm−1) and small nu, Greek21 (A″, 311.28 cm−1) bands of 1,2,4-triazine, a five membered ring having the point group Cs, has been studied at a resolution ranging from 0.002 to 0.003 cm−1. From the MW spectrum 58 transitions in the small nu, Greek20 level and 64 in the small nu, Greek21 level have been assigned. The small nu, Greek20 and small nu, Greek21 modes which are due to non-planar motions of the ring system are found to be nearly unperturbed. From a simultaneous analysis of IR and MW transitions band centers, rotational constants, and the quartic centrifugal distortion constants ΔJ, ΔJK, ΔK, small delta, GreekJ, and small delta, GreekK have been obtained using the Watson Hamiltonian, A-reduction, IIIr-representation.
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