Auto-ionised products from the reaction of sodium clusters with dioxygen: Theory and experiment

Elliott, Simon D.; Ahlrichs, Reinhart; Hampe, Oliver; Kappes, Manfred M.

doi:10.1039/b003706k

Cited by 24 publications

(28 citation statements)

References 33 publications

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“…For the isolated H 5 O 2 1 ion in the gas phase Born-Oppenheimer molecular dynamics simulations were made with DFT forces (AIMD) 21,22 using the TURBOMOLE package (V5-6) [23][24][25] The forces were calculated analytically using the BLYP functional 26 and the aug-cc-pVTZ basis set. 27 NVE simulations were performed such that the average of the kinetic energy corresponds to a temperature of about 100 K. The equilibrium structure was used as a starting point.…”

Section: Computationsmentioning

confidence: 99%

Environmental effects on vibrational proton dynamics in H₅O₂⁺: DFT study on crystalline H₅O₂⁺ClO₄⁻

Vener

Sauer

2005

Phys. Chem. Chem. Phys.

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The structure as well as IR and inelastic neutron scattering (INS) spectra of H 5 O 2 1 in crystalline H 5 O 2 1 ClO 4 À were simulated using Car-Parrinello molecular dynamics with the BLYP functional. The potential of the OÁ Á ÁH 1 Á Á ÁO fragment is very shallow. The Pnma structure, assumed in the X-ray study to be the most suitable choice, is a saddle point on the potential energy surface, while the P2 1 2 1 2 1 minimum structure is only 20 cm À1 lower in energy. The computed INS and IR spectra enable us to achieve a complete assignment of the observed spectra. The broad band between 1000 and 1400 cm À1 is due to the asymmetric stretch and one of the bending vibrations of the OÁ Á ÁH 1 Á Á ÁO fragment, while the band between 1600 and 1800 cm À1 is due to the bending vibration of the water molecules and the second bending of the OÁ Á ÁH 1 Á Á ÁO fragment. Comparison with the vibrational spectra of isolated H 5 O 2 1 , obtained using Born-Oppenheimer molecular dynamics simulation, reveals environmental effects on vibrational proton dynamics in strong H-bonded species. The most pronounced changes are found for the OÁ Á ÁH 1 Á Á ÁO bending modes because the two bending coordinates become distinctly different for the structure that the H 5 O 2 1 ion assumes in the crystal.

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Section: Computationsmentioning

confidence: 99%

Environmental effects on vibrational proton dynamics in H₅O₂⁺: DFT study on crystalline H₅O₂⁺ClO₄⁻

Vener

Sauer

2005

Phys. Chem. Chem. Phys.

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“…Its limitation is that quantum effects on the motion of the nuclei are not included. Figure 1 shows results of such a simulation for the MP2/cc-pVTZ PES (Turbomole code, [15][16][17] NVE ensemble, time step 0.484 fs, simulation time 4.35 ps, initial velocities randomly chosen at equilibrium structure by assuming a Boltzmann distribution, temperature about 350 K) together with the harmonic stick spectrum. This spectrum is an average over six trajectories.…”

mentioning

confidence: 99%

Gas‐Phase Infrared Spectrum of the Protonated Water Dimer: Molecular Dynamics Simulation and Accuracy of the Potential Energy Surface

Sauer

Döbler

2005

ChemPhysChem

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“…for sodium oxide clusters with 3 or more sodium atoms. 24,26,46 Due to the close to threshold ionisation, the observed progressions correspond most likely to parent ions. The observation of Na clusters results in part from the relatively high source Na concentrations required to enable observation of NaO and NaOH by PI-ToF, but also from their high ionisation efficiencies.…”

Section: Photo-ionisationmentioning

confidence: 99%

Reaction Kinetics of Meteoric Sodium Reservoirs in the Upper Atmosphere

2015

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The gas-phase reactions of a selection of sodium-containing species with atmospheric constituents, relevant to the chemistry of meteor-ablated Na in the upper atmosphere, were studied in a fast flow tube using multi-photon ionisation time-of-flight mass spectrometry.For the first time unambiguous observations of NaO and NaOH in the gas phase under atmospheric conditions have been achieved. This enabled the direct measurement of the rate constants for the reactions of NaO with H 2 , H 2 O and CO, and of NaOH with CO 2 , which at 300-310 K were found to be (at 2 confidence level): k(NaO + H 2 O) = (2.4 ± 0.6)  10 -10 cm 3 molecule -1 s -1 , k(NaO + H 2 ) = (4.9 ± 1.2)  10 -12 cm 3 molecule -1 s -1 , k(NaO + CO) = (9 ± 4)  10 -11 cm 3 molecule -1 s -1 , and k(NaOH + CO 2 + M) = (7.6 ± 1.6)  10 -29 cm 6 molecule -2 s -1 (P = 1 -4 Torr). The NaO + H 2 reaction was found to make NaOH with a branching ratio ≥ 99%. A combination of quantum chemistry and statistical rate theory calculations are used to interpret the reaction kinetics and extrapolate the atmospherically relevant experimental results to mesospheric temperatures and pressures. The NaO + H 2 O and NaOH + CO 2 reactions act sequentially to provide the major atmospheric sink of meteoric Na, and therefore have a significant impact on the underside of the Na layer in the terrestrial mesosphere: the newly determined rate constants shift the modelled peak to about 93 km, i.e. two km higher than observed by ground-based lidars. This highlights further uncertainties in the Na chemistry cycle such as the unknown rate constant of the NaOH + H reaction. The fast Narecycling reaction between NaO and CO and a re-evaluated rate constant of the NaO + CO 2 sink should be now considered in chemical models of the Martian Na layer.

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Auto-ionised products from the reaction of sodium clusters with dioxygen: Theory and experiment

Cited by 24 publications

References 33 publications

Environmental effects on vibrational proton dynamics in H₅O₂⁺: DFT study on crystalline H₅O₂⁺ClO₄⁻

Environmental effects on vibrational proton dynamics in H₅O₂⁺: DFT study on crystalline H₅O₂⁺ClO₄⁻

Gas‐Phase Infrared Spectrum of the Protonated Water Dimer: Molecular Dynamics Simulation and Accuracy of the Potential Energy Surface

Reaction Kinetics of Meteoric Sodium Reservoirs in the Upper Atmosphere

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Auto-ionised products from the reaction of sodium clusters with dioxygen: Theory and experiment

Cited by 24 publications

References 33 publications

Environmental effects on vibrational proton dynamics in H5O2+: DFT study on crystalline H5O2+ClO4−

Environmental effects on vibrational proton dynamics in H5O2+: DFT study on crystalline H5O2+ClO4−

Gas‐Phase Infrared Spectrum of the Protonated Water Dimer: Molecular Dynamics Simulation and Accuracy of the Potential Energy Surface

Reaction Kinetics of Meteoric Sodium Reservoirs in the Upper Atmosphere

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Environmental effects on vibrational proton dynamics in H₅O₂⁺: DFT study on crystalline H₅O₂⁺ClO₄⁻

Environmental effects on vibrational proton dynamics in H₅O₂⁺: DFT study on crystalline H₅O₂⁺ClO₄⁻