The far-infrared collision-induced spectrum of liquid and near-critical CO2

1985 ◽  
Vol 63 (12) ◽  
pp. 1559-1562 ◽  
Author(s):  
M. J. Clouter ◽  
A. R. W. McKellar
Keyword(s):  
Statistical Theory ◽  
Liquid Phase ◽  
Gas Phase ◽  
Infrared Spectra ◽  
Far Infrared ◽  
Density Fluctuations ◽  
Saturated Liquid ◽  
Phase Measurements ◽  
Critical Isochore ◽  
Far Infrared Spectra

Far-infrared (15–200 cm−1) absorption spectra of CO2 have been obtained (i) in the super-critical gas at 306 K with densities from 80 to 122 amagat, (ii) in the saturated liquid at 298, 272, and 236 K, and (iii) on the critical isochore in the temperature range 0.02 K < (T – Tc) < 2.0 K. The gas-phase measurements are in agreement with previous work, but an error in previously reported liquid-phase results is revealed. In contrast to the previous measurements of Mannik and Stryland on the ν1 band, the far-infrared spectra showed no measurable effects associated with density fluctuations in the critical region. A simple statistical theory is proposed to account for this result.

Hydrogen bonding in the gas phase: the thermodynamic properties of hydrogen fluoride-ether complexes and their far infrared spectra

1971 ◽  
Vol 322 (1548) ◽  
pp. 137-146 ◽  
Keyword(s):  
Hydrogen Bonding ◽  
Gas Phase ◽  
Infrared Spectra ◽  
Equilibrium Constants ◽  
Far Infrared ◽  
Methyl Ethyl ◽  
Rotational Contour ◽  
Stretching Vibration ◽  
Conformational Rearrangements ◽  
Far Infrared Spectra

The equilibrium constants of gas-phase complexes of HF with dimethyl, methyl ethyl and diethyl ether have been measured at several temperatures using the Benesi-Hildebrand approximation on the absorption band of the HF stretching vibration in the complex. From these, values of Δ H of — 43, — 38 and — 30 kJ mol -1 respectively, have been determined. They are interpreted in terms of conformational rearrangements of the ethers when they form hydrogen bonds. The far infrared spectra of the complexes with both HF and DF have also been recorded and in each case a band observed at around 180 cm -1 which is assigned to the intermolecular stretching mode of vibration. For the complex between HF and dimethyl ether a rotational contour has been observed at about 10 cm -1 .

Vibrational Spectra and Force Constants of Symmetric Tops, IL[1]

1985 ◽  
Vol 40 (10) ◽  
pp. 989-994 ◽  
Author(s):  
Hans Bürger ◽  
Martina Betzel
Keyword(s):  
Fourier Transform ◽  
Gas Phase ◽  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Far Infrared ◽  
Force Constants ◽  
Far Infrared Spectra ◽  
Anharmonicity Constants

Fourier Transform far infrared spectra of unstable stannyl chloride, bromide and iodide have been measured in the gas phase with a resolution of 0.04 cm-1. At pressures below 10 mbar, their lifetimes at 0 °C in preconditioned cells were found to be 10-30 min. The v3 fundamentals and hot bands of the series (n + 1)v3 - nv3 have been observed. Rotational J structure has been resolved for monoisotopic samples, and band origins v30, anharmonicity constants x33, ɑ3B and DJ0 values have been determined from the rovibrational analyses. The following v30 values were obtained: H3116Sn35Cl 375.470 (5), H3116Sn37Cl 367.689 (6), H3116Sn79Br 263.566 (5) and H3116SnI 209.759 (6) cm-1.

Far Infrared Spectra of Crystalline Iodine Monobromide and Iodine Monochloride

1974 ◽  
Vol 52 (7) ◽  
pp. 1081-1085 ◽  
Author(s):  
Hsiao-Chian Leung ◽  
Anthony Anderson
Keyword(s):  
Gas Phase ◽  
Infrared Spectra ◽  
Far Infrared ◽  
Iodine Monochloride ◽  
Theoretical Predictions ◽  
Iodine Monobromide ◽  
Thin Polycrystalline ◽  
Two Peaks ◽  
Far Infrared Spectra ◽  
Lattice Modes

Infrared spectra, in the range 20–400 cm−1, of thin polycrystalline films (at 80 °K) of iodine monobromide and the β-form of iodine monochloride have been recorded. For IBr, the intramolecular stretching region shows two peaks separated by 16 cm−1 and shifted appreciably from the gas phase value, indicating strong intermolecular interactions. Four lattice modes are also observed and assigned in accordance with group theoretical predictions. For β-ICl the spectrum of the stretching region confirms the presence of two distinct molecules with different bond lengths. The complexity of the ICl structure prevents an assignment of the ten observed lattice absorptions.

Far-infrared spectra of polycrystallineBa2YCu3O9−δ

1987 ◽  
Vol 36 (1) ◽  
pp. 846-849 ◽  
Author(s):  
G. A. Thomas ◽  
H. K. Ng ◽  
A. J. Millis ◽  
R. N. Bhatt ◽  
R. J. Cava ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Far Infrared ◽  
Far Infrared Spectra
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