The (ν1, ν4, ν2+ν3, ν3+ν5) Polyad of D328SiF around 1600 cm−1, Studied by High-Resolution FTIR Spectroscopy

✍ Scribed by N. Boulaftali; N. Ben Sari-Zizi; H. Najib; G. Graner; H. Bürger; E.B. Mkadmi; P. Pracna

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 316 KB
• Volume: 214
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.2002.8577

✦ Synopsis

The ν 1 (A 1 , 1578.31 cm -1 )/ν 4 (E, 1615.17 cm -1 ) Si-D stretching dyad of D 3 SiF has been studied by FTIR spectroscopy with a resolution of 2.4 × 10 -3 cm -1 . Only weak interactions of Coriolis ( K = ±1, = ±1) and α resonance ( K = ±2, = ∓1) type between ν 1 and ν 4 , and of (2, -4) type within ν 4 , were revealed. However, the v 1 = 1 and v 4 = 1 levels were found to be severely perturbed by the v 3 = v 5 = 1 (E, 1590.37 cm -1 ) and v 2 = v 3 = 1 (A 1 , 1604.25 cm -1 ) states. These perturbations are observable only near level crossings involving strong Coriolis and α interactions. The energy structure within these perturbers is severely complicated by strong Coriolis and α resonances and by (2, 2), (2,-1), and (2,-4) interactions as already revealed by the ν 2 (A 1 , 710.16 cm -1 ) and ν 5 (E, 701.72 cm -1 ) fundamentals. Interactions of the perturbing states with the ν 1 /ν 4 dyad are particularly evident in local crossings. In total, 12 transitions belonging to the dark states and 68 perturbation-allowed transitions within the ν 1 /ν 4 dyad have been detected among the more than 5000 transitions that have been assigned for the ν 1 /ν 4 dyad, with J max and K max of 50 and 30, respectively. Altogether about 85% of the assigned transitions were fitted with a standard deviation of 0.221 × 10 -3 cm -1 , leading to 61 parameters of the interacting polyad.