Raman Spectra Of Carbon Dioxide Research Articles

Tracking carbon dioxide adsorbate intramolecular dynamics in pure silica zeolite Silicalite-1 by in situ Raman scattering.

We report a series of high-quality Raman spectra of carbon dioxide (CO2) adsorbed at room temperature and at various equilibrium pressures, sampling the corresponding adsorption isotherm up to 12bar. The observed splitting in Fermi diad resonance lines, which were additionally split into two well-resolved components, arising from at least two different CO2 species, were compared to the same quantity in high-pressure gas/solid/liquid CO2 phases. Our studies provide material specific spectral data that could be useful in the detection, identification, and dynamical characterization of CO2 deposits, inclusions, or other forms in remote locations and of various origins, e.g. geological, planetary, stellar, and deap-sea sediments.

Fiber-enhanced Raman spectroscopy for highly sensitive H2 and SO2 sensing with a hollow-core anti-resonant fiber.

An innovative fiber-enhanced Raman gas sensing system with a hollow-core anti-resonant fiber is introduced. Two iris diaphragms are implemented for spatial filtering, and a reflecting mirror is attached to one fiber end that provides a highly improved Raman signal enhancement over 2.9 times than the typical bare fiber system. The analytical performance for multigas compositions is thoroughly demonstrated by recording the Raman spectra of carbon dioxide (CO2), oxygen (O2), nitrogen (N2), hydrogen (H2), and sulfur dioxide (SO2) with limits of detection down to low-ppm levels as well as a long-term instability < 1.05%. The excellent linear relationship between Raman signal intensity (peak height) and gas concentrations indicates a promising potential for accurate quantification.

Broadening of vibration Q-bands in the Raman spectrum of carbon dioxide due to critical density fluctuations

Detailed analysis of CARS-spectroscopy experimental data of the carbon dioxide Fermi dyad showed that critical density variance should not exceed 0.1 and the lifetime of critical fluctuations is more than 10 ns. To interpret the experimental data, an original calculation of the critical fluctuation contribution to spectral line, considering the lifetime of critical fluctuations, was performed.

The Raman spectra of carbon dioxide at the Fermi resonance, under pressures of 50 and 100 MPa, and at temperatures of 20?600�C

The Raman spectra of carbon dioxide at the Fermi resonance, under pressures of 50 and 100 MPa, and at temperatures of 20?600�C

Raman Spectra of Carbon Dioxide and its Isotopic Variants in the Fermi Resonance Region. Part IV: Temperature Dependence on Q-Branch Intensities from 300 K to 650 K

The temperature dependence of the intensities of the Q-branches in the Raman spectrum of gaseous CO2 in the Fermi resonance region was measured in the range from 300 K to 650 K. The intensity contours were reproduced by computer simulation, taking into account energy levels up to ( v1 v21 v3) = (30°0) as final states. Calibration curves are given for the determination of temperatures from the intensity distribution in the hot bands of the Raman spectrum of CO2.

Motional narrowing in thev1/2v2Fermi resonance diad of CO2

Studies of the v 1 and 2v 2 Q branches in the Raman spectrum of carbon dioxide have been carried out at a resolution of ∼30 MHz using the methods of Raman Amplification (Raman Gain) Spectroscopy. The v 1 band at 1286 cm-1 is not resolved at atmospheric pressure. The 2v 2 band, although similarly unresolved over the pressure range 120–760 Torr, is extremely narrow with a full width at half maximum (0·0076 cm-1 at 760 Torr) which is comparable with the Doppler width of a single transition and very markedly narrower than the width that would be expected of a single rotational S or O branch line at this pressure. This result is attributed to the effects of motional narrowing, which are thought to be very pronounced for 2v 2 because of the near coincidence of the individual J components within the Q branch.

The Raman spectrum of solid carbon dioxide at high pressure

Raman spectra of carbon dioxide were measured as functions of molar volume and temperature in the region 0 to 200 cm−1. In crystals constrained to remain at constant volume, the frequencies of the Raman active libron modes were found to shift much less with temperature than expected by comparison with solid nitrogen. In fact, when the slight expansion of the alloy steel cell is taken into account the frequency vs temperature plots show a slight positive temperature dependence as opposed to the fairly large negative shift observed in the nitrogen case. From these measurements, the value of the mode Gruneisen parameters (defined by γj=−d lnωj/d lnV) were determined to be 2.3±0.2, almost 3 times that predicted by the quadrupole–quadrupole model but in fairly good agreement with recent calculations by Gibbons and Klein, and Kobashi and Kihara. These are based on models which include short ranged intermolecular repulsive forces. Linewidths were measured and indicate that in carbon dioxide four phonon processes dominate the decay of the Eg mode, in contrast with nitrogen in which three phonon processes dominate.

Theoretical studies of the collision-induced Raman spectrum of carbon dioxide

Ab initio calculations have been performed on carbon dioxide to obtain the first derivatives of the dipole-quadrupole polarizability A and of the first hyperpolarizability β in the bending and asymmetric stretching modes. These derivatives are used to assess the relative contributions of A and β to the collision-induced Raman spectrum. It is concluded that most of the intensity arises from the mechanism involving the A tensor. Reasonable agreement is obtained with measured depolarization ratios and relative intensities for the v 2 and v 3 modes in compressed gaseous CO2.

Rayleigh and Raman scattering near the critical point of carbon dioxide

An experimental study of the behavior of depolarized Rayleigh and Raman spectra of carbon dioxide when approaching the critical temperature along the critical isochore is presented. The study of the depolarized Raman scattering was carried out on the Fermi diad ν1, 2ν2 and was supplemented by a study of the polarized Raman scattering. Contributions to the different physical mechanisms which can give rise to the depolarized spectra are carefully analyzed. We have shown that the orientational dynamics of CO2 molecules are unchanged by critical slowing down of the diffuse hydrodynamical mode associated to fluctuations of the order parameter in the range 0.01 °C&amp;lt;T–Tc&amp;lt;10 °C. Moreover we found that the frequency variation of the polarized Fermi diad can be well described using only density terms. The variation of the spectral intensities of the different polarized and depolarized bands is well explained in terms of only turbidity and multiple scattering phenomena owing to the intensive quasielastic polarized Rayleigh scattering.

ChemInform Abstract: THE INTENSITY DISTRIBUTION IN PURE ROTATIONAL RAMAN SPECTRA OF CARBON DIOXIDE AND NITROUS OXIDE TAKING INTO ACCOUNT CONTRIBUTIONS FROM THE 0110 STATE

Chemischer InformationsdienstVolume 8, Issue 5 Physical Inorganic Chemistry ChemInform Abstract: THE INTENSITY DISTRIBUTION IN PURE ROTATIONAL RAMAN SPECTRA OF CARBON DIOXIDE AND NITROUS OXIDE TAKING INTO ACCOUNT CONTRIBUTIONS FROM THE 0110 STATE K. ALTMANN, K. ALTMANNSearch for more papers by this authorW. KLOECKNER, W. KLOECKNERSearch for more papers by this authorG. STREY, G. STREYSearch for more papers by this author K. ALTMANN, K. ALTMANNSearch for more papers by this authorW. KLOECKNER, W. KLOECKNERSearch for more papers by this authorG. STREY, G. STREYSearch for more papers by this author First published: February 1, 1977 https://doi.org/10.1002/chin.197705001AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume8, Issue5February 1, 1977 RelatedInformation

The Raman spectra of carbon dioxide in liquid water and water-d2

The Raman spectra of carbon dioxide in liquid water and water-d2

Der Intensitätsverlauf im reinen Rotations-Raman-Spektrum von CO2 und N2O unter Berücksichtigung des 0110-Niveaus / Intensity Distribution in Pure Rotational Raman Spectra of CO2 and N2O Taking into Account Contributions from the 0110 State

Abstract The pure rotational Raman spectra of carbon dioxide and nitrous oxide have been recorded with argon laser excitation and a resolution of about 0.2 cm-1. As was found previously for acetylene, also for these molecules R-branch transitions in the excited II-states could be resolved clearly up to J=9. The relative intensity distribution has been analyzed quantitatively according to formulae derived previously. It turns out that the experimental intensity distribution is well reproduced by taking into account only the component of the anisotropic part of the polarizability tensor. Higher order contributions arising from the components could not be detected.

DENSITY EFFECTS IN THE RAMAN SPECTRUM OF CARBON DIOXIDE

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.

Polarization and Intensity Measurements in the Raman Spectrum of Carbon Dioxide

The relative intensities and the depolarizations (for unpolarized incident light) of the two principal Raman bands of carbon dioxide have been measured. The following results were obtained: ${\ensuremath{\rho}}_{1286}=0.18, {\ensuremath{\rho}}_{1389}=0.14, \frac{{I}_{1286}}{{I}_{1389}}=0.61.$

Intensity Measurements in the Raman Spectrum of Carbon Dioxide

A simple photographic method of measuring intensities in the Raman effect was devised. The ratio of the intensities of the strong Raman doublet of C${\mathrm{O}}_{2}$ was found to be 0.572 instead of 0.667 as roughly estimated by Dickinson, Dillon and Rasetti. This value (0.572) although in apparent disagreement with the calculations of Dennison and Adel is in fair agreement with Placzek's recent work. An exposure of 24 days brought out three lines in addition to the four commonly observed. They may be identified with three of the lines predicted by Dennison and Adel.

Rotational Structure of the Raman Band (0000) → (020±2) in Linear Symmetrical Molecules YX2

In connection with an attempt made by A. Langseth and the writer to interpret two faint lines in the Raman spectrum of carbon dioxide, the intensities have been calculated of the rotational lines associated with the transition (0000)\ensuremath{\rightarrow}(020\ifmmode\pm\else\textpm\fi{}2) in linear symmetrical molecules $X\ensuremath{-}Y\ensuremath{-}X$. The results agree with the more general formulas recently obtained by Placzek and Teller by a formally different method.

The Infrared Spectrum of Carbon Dioxide. Part II

Previous work by Fermi and by Dennison has shown that the principal features of the infrared and Raman spectra of carbon dioxide may be explained by taking account of the first order perturbation terms in the potential energy expression. It was not possible to predict the positions of the levels with any high degree of accuracy, however. The present paper extends this work by introducing a second order perturbation. The formula for the second order energy correction of a general linear symmetrical triatomic molecule is initially computed. This formula is then modified in order that it may be applicable to the carbon dioxide molecule in which resonance degeneracy plays an essential r\^ole. A review is made of the experimental data which determine the positions of the carbon dioxide vibrational energy levels. These include the results of a recent investigation of absorption bands appearing in the spectrum of Venus, as well as new and as yet unpublished data found by Barker and Wu. In all, twenty levels have been found and out of these, eleven are required to determine the anharmonic constants of the molecule. The remaining nine levels may then be predicted, and their positions are found to agree very accurately with the values obtained experimentally. A table is given showing the positions of a number of C${\mathrm{O}}_{2}$ infrared bands which while accessible to observation have not as yet been reported. The recent work by Langseth and Nielsen on the Raman spectrum of C${\mathrm{O}}_{2}$ is discussed.

The Infrared Spectrum of Carbon Dioxide. Part I

Previous work by Fermi and by Dennison has shown that the principal features of the infrared and Raman spectra of carbon dioxide may be explained by taking account of the first order perturbation terms in the potential energy expression. It was not possible to predict the positions of the levels with any high degree of accuracy, however. The present paper extends this work by introducing a second order perturbation. The formula for the second order energy correction of a general linear symmetrical triatomic molecule is initially computed. This formula is then modified in order that it may be applicable to the carbon dioxide molecule in which resonance degeneracy plays an essential r\^ole. A review is made of the experimental data which determine the positions of the carbon dioxide vibrational energy levels. These include the results of a recent investigation of absorption bands appearing in the spectrum of Venus, as well as new and as yet unpublished data found by Barker and Wu. In all, twenty levels have been found and out of these, eleven are required to determine the anharmonic constants of the molecule. The remaining nine levels may then be predicted, and their positions are found to agree very accurately with the values obtained experimentally. A table is given showing the positions of a number of C${\mathrm{O}}_{2}$ infrared bands which while accessible to observation have not as yet been reported. The recent work by Langseth and Nielsen on the Raman spectrum of C${\mathrm{O}}_{2}$ is discussed.

RAMAN EFFECTS WITH LIQUID AND SOLID CARBON DIOXIDE

This paper describes in detail methods of obtaining clear liquid carbon dioxide and clear solid carbon dioxide in tubes suitable for light-scattering experiments. A description is given of the new type of mercury arc employed as a source of incident light.For the first time, Raman spectra of carbon dioxide in the liquid and solid states are obtained, and compared with the known Raman spectrum of the substance in the gaseous state.Carbon dioxide is the first substance for which Raman spectra have been obtained for all three states.

The Raman and Infra-Red Spectra of Carbon Dioxide

MR. RASETTI'S examination of the Raman spectrum of carbon dioxide as reported in his letter in NATURE of Feb. 9 is of extreme interest. He points out (1) a coincidence between (a) the infra-red frequencies deduced from the Raman spectrum, namely, 1284 and 1392 cm.-1, and (b) the wave number difference between the band centres of the double doublet at 2.7 μ. and the doublet maxima at 4.25 μ as given by Schaefer and Philipps (Zeit. f. Physik, 36, 641; 1926), which are 1279 and 1381 cm.-1; and (2) that there is no known band in the infra-red spectrum of carbon dioxide which would correspond with either of these.