A New Rovibrational Analysis of the ν2, ν5 and 2ν3 Bands of Monoisotopic H3Si79Br

✍ Scribed by A. Ceausu; G. Graner; H. Burger; P. Pracna

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 659 KB
• Volume: 174
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1995.1284

✦ Synopsis

A high-resolution (\mathrm{FT}) infrared spectrum of (\mathrm{H}{3} \mathrm{Si}^{70} \mathrm{Br}) (resolution (0.0022 \mathrm{~cm}^{-1}) ) in the region (830-1050 \mathrm{~cm}^{-1}) was used to analyze the fundamental bands (\nu{2}\left(A_{1}\right)) and (\nu_{5}(E)). A total of 4392 transition wavenumbers for (\nu_{2}) and (\nu_{5}) have been fitted, together with 632 energy values for the (v_{3}=2) level, with a standard deviation of the fit of (0.123 \times 10^{-3} \mathrm{~cm}^{-1}). A model was used taking into account the strong Coriolis (x, y) resonance between (\nu_{2}) and (\nu_{\mathrm{s}}), and also three local resonances: (i) an accidental Coriolis-type resonance of (\nu_{5}) with (2 \nu_{3}) (crossing of ( (k l=-13), (v_{5}) (=1) ) and ( (K=14, v_{3}=2) ) for (J^{\prime}) between 16 and 17); (ii) an (l( \pm 2, \mp 1)) resonance of the ( (k l) (\left.=2, v_{s}=1\right)) and (\left(k l=-3, v_{s}=1\right)) levels, with a crossing for (J^{\prime}) between 58 and 59; and (iii) an accidental (l(\mp 1, \pm 2)) resonance between (\nu_{2}(K=3)) and (\nu_{5}\left(k l=1, A^{+}\right.)and (\left.A^{-}\right)). Some "forbidden" transitions, due to this last resonance, were observed and included in the fit. The (l)-doubling constant (q_{s}) and the Coriolis resonance parameters being strongly correlated, these two resonances cannot be treated independently. Hence, (q_{5}) was fixed at zero and a value of (0.09314238(58) \mathrm{cm}^{-1}) was obtained for (B \zeta_{25}). 1995 Academic Press. Inc.