Infrared and Raman spectra of solutions in liquid argon and krypton containing dimethyl ether or its fully deuterated isotopomer and (12)CO(2) or (13)CO(2) are investigated. The spectra lead to new data on the nu(1) (CO(2) )/2 nu(2) (CO(2) ) resonances appearing in the complex of CO(2) with the ether. The experimental data, and their interpretation, is supported by MP2/6-311++G(2d,2p) calculations of the cubic and quartic force constants and of the first and higher order dipole moment derivatives required for the modelling of the Fermi and Darling-Dennison resonances observed.
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http://dx.doi.org/10.1002/cphc.200900414 | DOI Listing |
Spectrochim Acta A Mol Biomol Spectrosc
March 2025
Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China. Electronic address:
The ν + 2ν + ν band of CO is dominated by weak absorption lines near 2.0 uμm, which has potential application in planetary atmosphere, astrophysical, and hydrocarbon fuel combustion investigations. High-quality spectral line parameters are the foundation of spectroscopic technology.
View Article and Find Full Text PDFAppl Spectrosc
October 2024
Laboratory of Ecological Instrumentation, Institute of Monitoring of Climatic and Ecological Systems, Tomsk, Russia.
Raman spectroscopy has great potential for quantitative analysis of natural gas. Helium is one of the components of natural gas and has a wide range of applications. It was believed that noble gases could not be detected using this technique due to the absence of their vibrational spectra.
View Article and Find Full Text PDFDiagnostics (Basel)
March 2023
Department of Conservative and Aesthetic Dentistry, Baghdad College of Dentistry, University of Baghdad, Baghdad P.O. Box 1417, Iraq.
This study evaluated the structural changes of enamel treated by the Regenerate system and carbon dioxide (CO) laser against acid challenge. Thirty human enamel slabs were prepared and assigned into three groups: Group I: untreated (control); Group II: treated with the Regenerate system; and Group III exposed to CO laser. All specimens were subjected to an acid challenge (pH 4.
View Article and Find Full Text PDFMolecules
December 2021
Laboratory of Ecological Instrumentation, Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch of the Russian Academy of Sciences, 634055 Tomsk, Russia.
In this work, the effect of nitrogen and carbon dioxide on the depolarization ratio of the ν band of methane in the pressure range of 0.1-5 MPa is studied. A high-sensitivity single-pass Raman spectrometer was used to obtain accurate results.
View Article and Find Full Text PDFJ Chem Phys
July 2021
Theoretical Chemistry Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
Modeling protoplanetary disks and other interstellar media that are not in local thermal equilibrium require the knowledge of rovibrational transition rate coefficients of molecules in collision with helium and hydrogen. We present a computational method based on the numerically exact coupled-channel (CC) method for rotational transitions and a multi-channel distorted-wave Born approximation (MC-DWBA) for vibrational transitions to calculate state-to-state rate coefficients. We apply this method to the astrophysically important case of CO-He collisions, using newly computed ab initio three-dimensional potential energy surfaces for CO-He with CO distorted along the symmetric and asymmetric stretch (ν and ν) coordinates.
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