Comparison between the density effects on the levels of the Raman spectra of the Fermi resonance doublet of the 12C16O2 and 13C16O2 molecules

1989 ◽  
Vol 91 (10) ◽  
pp. 5869-5881 ◽  
Author(s):  
Y. Garrabos ◽  
M. A. Echargui ◽  
F. Marsault‐Herail
Keyword(s):  
Raman Spectra ◽  
Fermi Resonance ◽  
Density Effects ◽  
Resonance Doublet

Raman spectral studies of solutions at elevated temperatures and pressures.13. Sodium formate – water

1993 ◽  
Vol 71 (10) ◽  
pp. 1728-1733 ◽  
Author(s):  
Richard J. Bartholomew ◽  
Donald E. Irish
Keyword(s):  
Raman Spectra ◽  
Elevated Temperatures ◽  
Sodium Formate ◽  
Fermi Resonance ◽  
Spectral Studies ◽  
Coupling Constant ◽  
Ambient Conditions ◽  
Modes Of Vibration ◽  
Resonance Doublet ◽  
Raman Spectral

Raman spectra of the formate anion in water (H2O and D2O) have been measured for four concentrations under ambient conditions and for two concentrations at temperatures ranging from 49 to 239 °C and a pressure of 10 MPa. Five of the six fundamental modes of vibration are polarized. This result is inconsistent with C2ν symmetry. The Fermi resonance doublet clearly results from the interaction of 2ν5 and ν1. The latter mode decreases in frequency as the temperature rises, thus increasing the coupling and hence the intensity of the 2ν5 component. The coupling constant, W, and the positions of the unperturbed bands [Formula: see text] and [Formula: see text] have been calculated. No evidence to support a bifurcated structure for the solvated anion was found.

Time-resolved remote Raman study of minerals under supercritical CO 2 and high temperatures relevant to Venus exploration

2010 ◽  
Vol 368 (1922) ◽  
pp. 3167-3191 ◽  
Author(s):  
Shiv K. Sharma ◽  
Anupam K. Misra ◽  
Samuel M. Clegg ◽  
James E. Barefield ◽  
Roger C. Wiens ◽  
...  
Keyword(s):  
High Temperature ◽  
Raman Spectra ◽  
High Temperatures ◽  
Ambient Pressure ◽  
Fermi Resonance ◽  
Time Resolved ◽  
Temperature Spectra ◽  
Resonance Doublet ◽  
Partial Dissociation ◽  
Surface Mineralogy

We report time-resolved (TR) remote Raman spectra of minerals under supercritical CO 2 (approx. 95 atm pressure and 423 K) and under atmospheric pressure and high temperature up to 1003 K at distances of 1.5 and 9 m, respectively. The TR Raman spectra of hydrous and anhydrous sulphates, carbonate and silicate minerals (e.g. talc, olivine, pyroxenes and feldspars) under supercritical CO 2 (approx. 95 atm pressure and 423 K) clearly show the well-defined Raman fingerprints of each mineral along with the Fermi resonance doublet of CO 2 . Besides the CO 2 doublet and the effect of the viewing window, the main differences in the Raman spectra under Venus conditions are the phase transitions, the dehydration and decarbonation of various minerals, along with a slight shift in the peak positions and an increase in line-widths. The dehydration of melanterite (FeSO 4  · 7H 2 O) at 423 K under approximately 95 atm CO 2 is detected by the presence of the Raman fingerprints of rozenite (FeSO 4  · 4H 2 O) in the spectrum. Similarly, the high-temperature Raman spectra under ambient pressure of gypsum (CaSO 4  · 2H 2 O) and talc (Mg 3 Si 4 O 10 (OH) 2 ) indicate that gypsum dehydrates at 518 K, but talc remains stable up to 1003 K. Partial dissociation of dolomite (CaMg(CO 3 ) 2 ) is observed at 973 K. The TR remote Raman spectra of olivine, α-spodumene (LiAlSi 2 O 6 ) and clino-enstatite (MgSiO 3 ) pyroxenes and of albite (NaAlSi 3 O 8 ) and microcline (KAlSi 3 O 8 ) feldspars at high temperatures also show that the Raman lines remain sharp and well defined in the high-temperature spectra. The results of this study show that TR remote Raman spectroscopy could be a potential tool for exploring the surface mineralogy of Venus during both daytime and nighttime at short and long distances.

Raman Spectra of Carbon Dioxide and its Isotopic Variants in the Fermi Resonance Region: II. 12C18O2

1978 ◽  
Vol 32 (4) ◽  
pp. 401-402 ◽  
Author(s):  
H. W. Klöckner ◽  
H. Finsterhölzl ◽  
K. Srinivasan ◽  
H. W. Schrötter
Keyword(s):  
Carbon Dioxide ◽  
Raman Spectra ◽  
Resonance Region ◽  
Fermi Resonance ◽  
Region Ii

DENSITY EFFECTS IN THE RAMAN SPECTRUM OF CARBON DIOXIDE

1952 ◽  
Vol 30 (2) ◽  
pp. 99-110 ◽  
Author(s):  
H. L. Welsh ◽  
P. E. Pashler ◽  
B. P. Stoicheff
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Raman Spectrum ◽  
Relative Intensity ◽  
Intermolecular Forces ◽  
Anisotropic Scattering ◽  
Fermi Resonance ◽  
Intensity Effect ◽  
Density Effects ◽  
Frequency Changes

Two Raman tubes, one of quartz and one of glass, capable of withstanding pressures up to 75 and 300 atm. respectively, were used to study density effects in the Raman spectrum of carbon dioxide. The components of the ν1 band show changes in frequency and relative intensity with increasing density. An analysis shows that the frequency changes are due to a lowering of the frequency of 2ν2, in Fermi resonance with ν1, with increasing density. The intensity effect, however, is not completely explained by the change in the sharpness of the resonance. In the high pressure gas and in the liquid faint bands corresponding to the Raman inactive frequencies, ν2 and ν3, are observed. The effect of increasing density on the rotational Raman spectrum can be explained in terms of the broadening of anisotropic scattering by intermolecular forces.

Fermi resonance in Raman spectra of crystalline 5-aminotetrazole monohydrate

1984 ◽  
Vol 15 (4) ◽  
pp. 232-236 ◽  
Author(s):  
Adriano Bigotto ◽  
Gianna Castellani
Keyword(s):  
Raman Spectra ◽  
Fermi Resonance

Infrared Study of Benzaldehyde and 4-Substituted Benzaldehydes in Carbon Tetrachloride and/or Chloroform Solutions: Aldehydic CH Group

1992 ◽  
Vol 46 (2) ◽  
pp. 293-305 ◽  
Author(s):  
Richard A. Nyquist ◽  
Sam E. Settineri ◽  
Davin A. Luoma
Keyword(s):  
Carbon Tetrachloride ◽  
The Other ◽  
Fermi Resonance ◽  
Infrared Study ◽  
Resonance Doublet ◽  
Substituted Benzaldehydes ◽  
Linear Manner

The vCH and 2 δCH Fermi resonance doublet and unperturbed vCH and unperturbed 2 δCH for 4- x-benzaldehydes increase in frequency as the mole % CHCl3/CCl4 increases. One portion of the vCH and 2 δCH Fermi doublet occurs in the region 2726–2746 cm−1 and the other portion of the Fermi doublet occurs in the region 2805–2845 cm−1. The unperturbed vCH for 4- x-benzaldehydes is assigned in the region 2760–2810 cm−1. Submaxima are also noted for 4- x-benzaldehydes in the region 2726–2810 cm−1 and these bands are assigned to combination tones. The vasym. NO2 mode occurs in the region 1533.60–1538.73 cm−1 and the vsym. NO2 mode occurs in the region 1344.07–1345.63 cm−1 for 4-nitrobenzalde-hyde in CHCl3/CCl4 solutions. The vsym. NO2 mode shifts to lower frequency by ∼4.8 cm−1, while the vsym. NO2 mode shifts to higher frequency by ∼1.6 cm−1 in going from CCl4 solution to CHCl3 solution. The vCN mode for 4-cyanobenzaldehyde increases in frequency in a nonlinear manner as the mole % CHCl3/CCl4 increases. The vOH mode for 4-hydroxybenzaldehyde decreases in frequency in essentially a linear manner as the mole % CHCl3/CCl4 increases. The δCH mode for 4- x-benzaldehydes increases in frequency as the mole % CHCl3/CCl4 increases; however, neither unperturbed vCH nor δCH correlates with Hammett σp values.

Sign in / Sign up

Export Citation Format

Share Document