Using new high-resolution Fourier transform spectra recorded at the University of Denver in the 2-µm region, a new and more extended analysis of the 2nu(1) + nu(3) and 3nu(3) bands of nitrogen dioxide, located at 4179.9374 and 4754.2039 cm(-1), respectively, has been performed. The spin-rotation energy levels were satisfactorily reproduced using a theoretical model that takes into account both the Coriolis interactions between the spin-rotation energy levels of the (201) vibrational "bright" state with those of the (220) "dark" state. The interactions between the (003) bright state with the (022) dark state were similarly treated. The spin-rotation resonances within each of the NO(2) vibrational states were also taken into account. The precise vibrational energies and the rotational, spin-rotational, and coupling constants were obtained for the two dyads {(220), (201)} and {(022), (003)} of the (14)N(16)O(2) interacting states. From the experimental line intensities of the 2nu(1) + nu(3) and 3nu(3) bands, a determination of their vibrational transition moment constants was performed. A comprehensive list of line positions and line intensities of the {2nu(1) + 2nu(2), 2nu(1) + nu(3)} and the {2nu(2) + 2nu(3), 3nu(3)} interacting bands of (14)N(16)O(2) was generated. In addition, assuming the harmonic approximation and using the Hamiltonian constants derived in this work and in previous studies (A. Perrin, J.-M. Flaud, A. Goldman, C. Camy-Peyret, W. J. Lafferty, Ph. Arcas, and C. P. Rinsland, J. Quant. Spectrosc. Radiat. Transfer 60, 839-850 (1998)), we have generated synthetic spectra for the {(022), (003)}-{(040), (021), (002)} hot bands at 6.3 µm and for the {(220), (201)}-{(100), (020), (001)} hot bands at 3.5 µm, which are in good agreement with the observed spectra. Copyright 2000 Academic Press.
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http://dx.doi.org/10.1006/jmsp.2000.8064 | DOI Listing |
J Phys Chem A
August 2023
Instituto de Ciencias Nucleares, UNAM. A.P.70-543, Circuito Exterior, C.U., 04510 Mexico City, Mexico.
A polyad-conserving algebraic model applied to vibrational excitations of asymmetric isotopologues of CO is presented. First, the problem of vibrational excitations is studied by taking into account only the minimum subspace of states to characterize the Fermi interaction. This analysis allows an estimation of the force constants as well as the feasibility of describing the system in a local mode scheme, in terms of (2) operators associated with Morse ladder operators for the stretches.
View Article and Find Full Text PDFJ Chem Phys
May 2022
Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.
The water molecule occurs in two nuclear-spin isomers that differ by the value of the total nuclear spin of the hydrogen atoms, i.e., I = 0 for para-HO and I = 1 for ortho-HO.
View Article and Find Full Text PDFJ Chem Phys
March 2018
Istituto Nazionale di Ottica-CNR, Dipartimento di Fisica-Università degli Studi di Firenze and European Laboratory for Non-linear Spectroscopy, Via N. Carrara 1, Sesto Fiorentino, Italy.
We investigated a set of nineteen CO transitions of the 2ν + ν ro-vibrational band in the spectral region from 5064 to 5126 cm at different pressures, using frequency-comb Vernier spectroscopy. Our spectrometer enabled the systematic acquisition of molecular absorption profiles with high precision. Spectroscopic parameters, namely, transition frequency, linestrength, and self-pressure broadening coefficient, have been accurately determined by using a global fit procedure.
View Article and Find Full Text PDFJ Chem Phys
February 2017
Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Quantum state resolved reactivity measurements probe the role of vibrational symmetry on the vibrational activation of the dissociative chemisorption of CH on Ni(111). IR-IR double resonance excitation in a molecular beam was used to prepare CH in three different vibrational symmetry components, A, E, and F, of the 2ν antisymmetric stretch overtone vibration as well as in the ν+ν symmetric plus antisymmetric C-H stretch combination band of F symmetry. The quantum state specific dissociation probability S (sticking coefficient) was measured for each of the four vibrational states by detecting chemisorbed carbon on Ni(111) as the product of CH dissociation by Auger electron spectroscopy.
View Article and Find Full Text PDFJ Phys Chem B
March 2014
Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland.
The S0 → S1 vibronic spectrum and S1 state nonradiative relaxation of jet-cooled keto-amino 5-fluorocytosine (5FCyt) are investigated by two-color resonant two-photon ionization spectroscopy at 0.3 and 0.05 cm(–1) resolution.
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