Rotation spectra, vibration

It is well known that the v, band of liquid acetonitrile is significantly asymmetric due to an overlap of hot band transitions in the low frequency side. A study of gas phase rotation-vibration spectrum [19] showed that the hot band transition from the first exited state of the degenerated C-C = N bending v8 mode, v hl = v + v8 - vs, has its center at 4.944 cm 1 lower than that of the fundamental transition, v,. Also the presence of v,h2 = v, + 2v8 - 2v8 transition is expected. The careful study on the v band of liquid acetonitrile by Hashimoto et al [20] provided the reorientational and vibrational relaxation times of liquid acetonitrile molecule. They corrected the contribution by the hot band transition using the Boltzmann population law and approximated the v , v,hl, 2h2, and v, + v4 bands by Lorentzian curves. 

Figure 4.3-1 Rotation-vibration spectrum of A infrared spectrum in absorbance units for the experimental conditions, see also Fig. 4.3.1-9. B Raman spectrum, compiled from several spectra recorded under different conditions, but plotted on an approximately equivalent intensity scale. The peaks of r l and vj are off scale (pressure 13 kPa, laser power 6 to 10 W at 514.5 nm, spectral slitwidth about 2 cm ).

Figure 4.3-7 Rotation-vibration spectrum of C2H2 (5 hPa, 25 °C, l(i cm) at a spectral resolution of 0,05 cm with the inset the intensity alternation due to spin statistics in the /5-fundamenlal is illustrated (the underlying fine structure is from a hot band transition with its 0-branch shifted to lower wavenumbers compared to the fundamental).

Figure 4.3-8 Rotation-vibration spectrum of CH3I (prolate symmetric top 41 hPa, 25 °C, 10 cm) at a spectral resolution of 0.05 cm-. ...

It is well known that the v, band of liquid acetonitrile is significantly asymmetric due to overlap of hot band transitions in the low frequency side. From a study of gas phase rotation-vibration spectrum [16], the hot band transition from the first exited state of the degenerate C-C=N bending Vj, mode, v, = V, + Vg - Vg, has its center at 4.944 cm ... 

As we demonstrated above, CVPT can be used to compute properties of rotation-vibration states of H2CO. To calculate the rotation-vibration spectrum, we must also be able to calculate the intensity of the transition between the energy eigenstate vT M J ) and vfM7). Here the eigenstates are defined in terms of their total angular momentum... 

Kartavtsev, O.I. and Malykh, A. V., Low-energy three-body dynamics in binary quantum gases, J. Phys. B, 40, 1429, 2007 Universal description of the rotational-vibrational spectrum of three particles with zero-range interactions, Pis tna 7h. Eksp. Teor. Fiz., 86, 713, 2007. 

The VCD spectrum of (S)-(-)-epoxypropane [10] in the liquid and in the gaseous phase shows the splitting of the degenerate vibrational modes of the methyl group. Its analysis verified the VCD theory of the perturbed vibrational degenerate modes. Using a resolution of 1 cm i, the CD in the rotational-vibrational spectrum of (R)-(-h)-methyloxirane has been measured with the result that the Q branch in some bands has the opposite sign to the R and P branches. This can be explained if methyloxirane (in spite of its chirality) is an approximate symmetrical top. 

Unit Rotation-vibration spectrum of HCI (accurate computation of spectroscopic quantities impact of electron correlation and anharmonicity)... 

Methane plays an important role in atmospheric and astrophysical chemistry. Its rotation-vibration spectrum is of key importance for models of the atmospheres of bodies ranging from Titan to brown dwarfs. Any temperature-dependent model of the methane spectrum requires comprehensive information on the associated transition intensities. 

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