Interpretation of the infrared spectrum of ozone trapped in inert matrices

The thermally activated recombination reaction O+O2→O3 is observed in solid xenon matrices and in free-standing crystals of xenon at 14–25 K on the time scale 102–105 s. The reactants are prepared as spatially separated O...O2 pairs immobilized in solid Xe at 10 K by 266 nm photodissociation of O3 precursor molecules. The temperature dependence of the ozone recovery rate yields an activation energy for diffusion of O atoms in solid xenon of 2.0±0.5 kJ/mol. This value also represents an upper limit to the potential energy barrier to the O+O2 recombination reaction itself. In dilute samples (mole fraction of ozone less than 2×10−4) more than 90% of the initial O3 is recovered during the warming cycle. Only a small fraction of O atoms (<20%) escape geminate recombination with the partner oxygen molecule within the pair and react with other O2 molecules or O atoms. The experimental results are interpreted within the framework of a continuous diffusion model in which the initial spatial distribution of reactants is nonrandom.

Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Diffusion-limited geminate recombination of O+O2 in solid xenon

Benderskii¹,

Wight²

1996

“…6 in the evaluation of the net matrix distortion and the vibrational energy levels. Results concerning energy levels have thus been given for both fcc and hcp RG lattice structures, distorted around single (S1) and double (S2) substitutional sites in order to investigate the possibility of sites other than those determined before.…”

Section: B Discussion and Conclusionmentioning

confidence: 99%

“…͑4͒ and ͑5͔͒. 6 ͑iv͒ The Born-Oppenheimer approximation is applied to separate the study of high frequency modes ͑vibration͒ from low frequency ones ͑libration and lattice vibrations͒. 7 Then considering the matrix atoms and the center-of-mass of the trapped molecule as being fixed with respect to the oxygen atoms of O 3 , the vibrational motion of the latter inside the matrix is studied.…”

Section: Theoretical Modelmentioning

confidence: 99%

Spectroscopy of O3 trapped in rare gas matrices. II. Vibrational energies and transition moments of low-lying levels

Chabbi

Dahoo

Lakhlifi

1999

Self Cite

Articles you may be interested inMeasurement of the electronic transition dipole moment by Autler-Townes splitting: Comparison of three-and four-level excitation schemes for the Na 2 A Σ u + 1 − X Σ g + 1 systemThe theoretical model described in part I is applied to calculate the vibrational energies and transition moments for low-lying levels of O 3 trapped in rare gas matrices. Results are given for molecules trapped in distorted face-centered-cubic ͑fcc͒ and hexagonal-closed-packed ͑hcp͒ lattice structures. New harmonic and anharmonic constants are determined that lead to matrix dependent calculated energy levels. Changes are significant for harmonic and third-order anharmonic ones. Moreover the symmetry of the potential in which the ozone oxygen nuclei move is shown to be altered. Calculated energy levels compare well with observed ones and allow predictions of unobserved ones. The 2 3 → 3 fluorescence observed in different rare gas matrices is confirmed. Transition moments hardly differ from one matrix to the other for 2 3 → 3 and 1 ϩ 3 transitions although for the latter, it is one order-of-magnitude higher in a double than in a single substitutional site.

“…Two distinct substitutional trapping sites, identified from a doublet structure of the absorptions, a single ͑high frequency line, called HF͒ and a double ͑low frequency line, called LF͒ one in a face-centered-cubic ͑fcc͒ lattice were experimentally characterized, and confirmed by theoretical analysis. 1,2 This work is now completed by a study of the vibrational relaxation of O 3 in these matrices by IR-IR double resonance ͑DR͒ and laser induced fluorescence ͑LIF͒ experiments. 3,4 Excited molecules trapped in a solid matrix can dissipate the energy absorbed from a pulsed laser either radiatively or nonradiatively.…”

Section: Introductionmentioning

confidence: 99%

Vibrational relaxation study of O3 in rare gas and nitrogen matrices by time resolved infrared–infrared double resonance spectroscopy

Dahoo

Jasmin

Brosset

et al. 1998

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Articles you may be interested inTime-resolved infrared absorption studies of the solvent-dependent vibrational relaxation dynamics of chlorine dioxide J. Chem. Phys. 123, 084503 (2005); 10.1063/1.2000234 Erratum: "The spectroscopy and IVR dynamics of HOCl in the v OH =6 region, probed by infrared-visible double resonance overtone excitation" [J.Vibrational and rotational collisional relaxation in CO 2 -Ar and CO 2 -He mixtures studied by stimulated Ramaninfrared double resonanceThe spectroscopy and intramolecular vibrational energy redistribution dynamics of HOCl in the v OH =6 region, probed by infrared-visible double resonance overtone excitation Eigenstate resolved infrared-infrared double-resonance study of intramolecular vibrational relaxation in benzene: First overtone of the CH stretch