Reactive scattering of H and D atoms. II. isotope effect on the angular distribution of H, D + NO2

The recombination reactions of gas-phase hydrated electrons (H2O)n˙(-) with CO2 and O2, as well as the charge exchange reaction of CO2˙(-)(H2O)n with O2, were studied by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry in the temperature range T = 80-300 K. Comparison of the rate constants with collision models shows that CO2 reacts with 50% collision efficiency, while O2 reacts considerably slower. Nanocalorimetry yields internally consistent results for the three reactions. Converted to room temperature condensed phase, this yields hydration enthalpies of CO2˙(-) and O2˙(-), ΔHhyd(CO2˙(-)) = -334 ± 44 kJ mol(-1) and ΔHhyd(O2˙(-)) = -404 ± 28 kJ mol(-1). Quantum chemical calculations show that the charge exchange reaction proceeds via a CO4˙(-) intermediate, which is consistent with a fully ergodic reaction and also with the small efficiency. Ab initio molecular dynamics simulations corroborate this picture and indicate that the CO4˙(-) intermediate has a lifetime significantly above the ps regime.

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“…Hydrated electrons in the gas phase [1][2][3] have been known for more than 30 years. Today they are very well characterized spectroscopically.…”

Section: Introductionmentioning

confidence: 99%

Charge transfer reactions between gas-phase hydrated electrons, molecular oxygen and carbon dioxide at temperatures of 80–300 K

Akhgarnusch

Tang

Zhang

et al. 2016

Phys. Chem. Chem. Phys.

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“…But the planar ionic configuration overrules the electronic trend to sphericity and we have an oblate cluster. For the further clusters, the global deformation is basically determined by the electronic structure [33,34]. The clusters with N el = 10 are strongly prolate and close to axial symmetry, those with N el = 18 are weakly prolate, and the samples with N el = 12 triaxial.…”

mentioning

confidence: 99%

Orientation averaged angular distributions of photo-electrons from free Na clusters

et al. 2010

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“…We have been concerned with the dynamic consequences of vibrational excitation due to exciton trapping. An analogous process involves vibrational predissociation of a rare-gas cluster due to hole trapping, as proposed by Haberland [49]. Haberland's mechanism [49] involves the vertical ionization of Ar, , which will subsequently result in the production of an Ar; diatomic molecular ion within the cluster, as discussed in section 5.…”

Section: Electronic Exciton Excitationmentioning

confidence: 96%

Level Structure and Dynamics of Clusters

Jortner

1984

Ber Bunsenges Phys Chem

119

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Some features of the structure, the dynamics of nuclear motion, the nature of electronic states, excited-state energetics and relaxation phenomena in "isolated" nonmetallic clusters are reviewed, with an emphasis on the interrelationship between the characteristics of molecular and condensed phase systems. PrologueThe search for unifiable concepts in chemistry and physics constitutes a central scientific endeavour. Each of the traditional areas of solid-state physics and molecular physics rests on a set of such unified concepts. In traditional solid-state physics one encounters the ubiquity of ordered structures with (approximate) symmetry of a periodic space group [I]. In addition, and of considerable interest, positional and compositional disordered materials [2] also exist. The density of states for an elementary excitation, e.g., phonons, electrons and excitons, is continuous spanning a finite energy range. Finally, the characteristic length of elementary excitations, e. g., phonon wavelength, electron mean free path and coherence lengths, are considerably shorter than the sample dimensions. On the other hand, molecular physics deals with finite sets of bound atoms, whose structure can be specified in terms of permutation symmetry [3] and (approximate) point group symmetry [4]. The fundamental vibrational excitations are discrete, being classified in terms of normal and local modes. The electronic excitations are also discrete below the first ionization potential. These discrete features of the low-lying excitations in molecular systems are qualitatively different from the continuous level structure in solids. The atomic structure and the level structure of elementary excitations in clusters, i. e., finite aggregates [ 5 , 61, cannot be characterized in terms of the conceptual framework, which rests solely on one of these two traditional disciplines. The area of the physics and chemistry of clusters, which is the subject matter of this Discussion Meeting, bridges the gap between solid-state and molecular physics. I would like t o dwell on some features of level structures and dynamics of "isolated" clusters. In 1977, when modern cluster physics was in the embryonic stages, Friedel wrote [7]: "Clean and isolated clusters in vacuum are a theoretician's dream". This dream has come true! The remarkable progress in the areas of supersonic jets and cluster beams [8, 91 makes clean and isolated clusters amenable t o experimental interrogation, providing the basis for intensive and extensive experimental and theoretical effort. There are some compelling reasons for the study of isolated clusters.A . Exploration of new basic physical phenomena. These are finite systems with a congested spectrum of energy levels (for electronic states, phonons, etc.) [lo]. The level structure can be varied continuously by changing the cluster size. Accordingly, one can accomplish a "continuous transition" from molecular to solid-state systems.B. Microscopic approach to macroscopic phenomena, such as nucleation, adsorption and desorpti...

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Reactive scattering of H and D atoms. II. isotope effect on the angular distribution of H, D + NO2

Cited by 26 publications

References 19 publications

Charge transfer reactions between gas-phase hydrated electrons, molecular oxygen and carbon dioxide at temperatures of 80–300 K

Charge transfer reactions between gas-phase hydrated electrons, molecular oxygen and carbon dioxide at temperatures of 80–300 K

Orientation averaged angular distributions of photo-electrons from free Na clusters

Level Structure and Dynamics of Clusters

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