FTIR Study of the ν1/ν4 Bands of D3Si35Cl near 1600 cm−1

✍ Scribed by K. Akkad; N.Ben Sari-Zizi; H. Bürger; E.B. MKadmi

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 226 KB
• Volume: 213
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.2002.8540

✦ Synopsis

The ν 1 (A 1 , 1583.22 cm -1 ) and ν 4 (E, 1615.33 cm -1 ) Si-D stretching bands of monoisotopic D 3 Si 35 Cl have been studied by FTIR spectroscopy with a resolution of 3.3 × 10 -3 cm -1 . We have assigned 2341 rovibrational lines for ν 1 (J max = 70, K max = 19) and 6207 for ν 4 (J max = 75, K max = 27). Both ( K = ±1, = ±1) and ( K = ±2, = ∓1) interactions connect the v 1 = 1 and v 4 = 1 levels, the latter exerting moreover a weak (2, 2) interaction. These interactions were taken into account in a nonlinear least-squares fit, refining 29 free parameters with a standard deviation of 0.257 × 10 -3 cm -1 over 6722 nonzeroweighted data. Blended lines and about 250 of the 330 lines belonging to the K = 11 subband of ν 1 and the K K = -6 subband of ν 4 were zero-weighted because they are locally perturbed respectively by the neighboring upper states of the 2ν 3 + ν 6 (E, 1561.95 cm -1 ) and 3ν 3 (A 1 , 1604.81 cm -1 ) bands. Equivalent fits were obtained for altogether three different models obeying constraints according to the theory of unitary equivalent reductions of the rovibrational Hamiltonian. By means of a band contour simulation both the transition moment ratio |M 1 : M 4 | = 0.67 and a positive sign of the Coriolis intensity perturbation were determined.