I-Resonance Perturbation of IR Intensities in 12C2H2 near 13.7 μm

✍ Scribed by M. Weber; W.E. Blass; G.W. Halsey; J.J. Hillman

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 820 KB
• Volume: 165
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1994.1114

✦ Synopsis

Using TDL and FT spectrometric data at 0.0005 and (0.0025 \mathrm{~cm}^{-1}) spectral resolution, respectively, individual line intensities of the (v_{5}) fundamental and the seven strongest hot bands, (v_{4}+) (\nu_{5} \leftarrow \nu_{4}) and (2 \nu_{5} \leftarrow \nu_{5}), of ({ }^{12} \mathrm{C}{2} \mathrm{H}{2}) in the (13.7-\mu \mathrm{m}) region have been measured. Except for the (2 \nu_{5}^{2 f} \leftarrow \nu_{5}^{1 f}) hot band, strong intensity perturbation due to (/)-type doubling and resonances have been quantitatively determined for all hot bands. The zeroth-order vibrational dipole moment derivative for the (v_{5}) bending mode is identical within (10 %) for all bands observed. Since an extra factor of (\frac{1}{2}) appears in the square vibrational transition moment for the combination band, its intensity is reduced by half and is comparable in magnitude to the (2 v_{5} \leftarrow \nu_{5}) hot bands. For the (v_{5}) fundamental a square dipole moment derivative of (\Gamma_{v}^{2}=0.09069(24) D^{2}) has been determined.
i) 1994 Academic Press, Inc