Collisional deactivation of potassium (52PJ) by molecular hydrogen. Identification of the primary quenching channel

Lin, King‐Chuen; Schilowitz, Alan M.; Wiesenfeld, J. R.

doi:10.1021/j150670a033

Cited by 16 publications

(2 citation statements)

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“…Among the states we consider only K[5P] has enough energy for the chemical reaction. Early studies on the reactivity of this state have found that the relative contribution of the chemical pathway appears to be small (upper limit of 1% of total deactivation), while its quenching proceeds to the lower laying K[5S] and K[3D] states instead of the ground state K[4S] (Lin and Schilowitz 1984). Later studies where able to detect the formation of KH from K[5P] confirming the presence of the reaction channel (Liu and Lin 1996), as well as the non-reactive de-excitation pathways (Wong et al 1999).…”

Section: Excited State Chemistrymentioning

confidence: 99%

Electron Densities and Alkali Atoms in Exoplanet Atmospheres

Lavvas

Koskinen

Yelle

2014

ApJ

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We describe a detailed study on the properties of alkali atoms in extrasolar giant planets, and specifically focus on their role in generating the atmospheric free electron densities, as well as their impact on the transit depth observations. We focus our study on the case of HD 209458 b, and we show that photoionization produces a large electron density in the middle atmosphere that is about two orders of magnitude larger than the density anticipated from thermal ionization. Our purely photochemical calculations though result in a much larger transit depth for K than observed for this planet. This result does not change even if the roles of molecular chemistry and excited state chemistry are considered for the alkali atoms. In contrast, the model results for the case of exoplanet XO-2 b are in good agreement with the available observations. Given these results we discuss other possible scenarios, such as changes in the elemental abundances, changes in the temperature profiles, and the possible presence of clouds, which could potentially explain the observed HD 209458 b alkali properties. We find that most of these scenarios can not explain the observations, with the exception of a heterogeneous source (i.e. clouds or aerosols) under specific conditions, but we also note the discrepancies among the available observations. Subject headings: planetary systems planets and satellites: atmospheres, composition, individual (HD 209458 b, XO-2 b)

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Section: Excited State Chemistrymentioning

confidence: 99%

Electron Densities and Alkali Atoms in Exoplanet Atmospheres

Lavvas

Koskinen

Yelle

2014

ApJ

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“…In recent decades, the reactions between the K atom and the H 2 molecule have been extensively studied in both experiments [1][2][3][4][5][6][7][8][9][10] and theory [11,12]. The K atom is always excited to the excited state in an experiment using a laser technique because the K + H 2 reaction is highly endothermic in the ground state.…”

Section: Introductionmentioning

confidence: 99%

Significant non-adiabatic effects of the K(4s²S) + H₂ reaction

Li,

Wen,

Niu

et al. 2023

J. Phys. B: At. Mol. Opt. Phys.

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The non-adiabatic dynamical calculations of the K(4s2S) + H2(v0 = 1, 2, j0 = 0) reaction are carried out using time-dependent wave packet method. The non-adiabatic dynamics results such as reaction probabilities, integral cross sections are calculated and compared with previous adiabatic values. The adiabatic values are several tens of times larger than that of non-adiabatic results. The non-adiabatic effect becomes stronger with the increase of the number of excited vibrational states. In addition, the excitation of vibrational states of H2 can increase the reaction probability of the reaction channel. However, the KH product is still hardly formed through the K(4s2S) + H2 reaction, even if the H2 molecule is excited to high vibrational excited state, which also leads to the opposite conclusion from adiabatic results. The forward biased differential cross sections indicate that direct stripping mechanism plays a dominant role in the reaction.

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Dynamics and Kinetics of Metal Atoms in the Gas Phase

Lin

1992

J Chinese Chemical Soc

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The review is divided into four sections. We first consider the varied behavior of K n2S and n2D states in their chemical reactivity and physical characterization. We review the effect of orbital alignment of an electronically excited metal atom on the cross section of energy transfer or chemical reaction, and report the technique of a single supersonic jet employed to measure this effect on the Ca spin‐changing collision. We discuss the effects of temperature and isotopic mass on the distribution of rotational quantum number of the product MgH to identify the reaction mechanism of Mg(1P1) + H2. The final concerns are the quantum yield, fine‐structure branching ratio and rate of collisional mixing for the K 2PJ doublets following photodissociation of KI at 193 nm.

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Collisional deactivation of potassium (52PJ) by molecular hydrogen. Identification of the primary quenching channel

Cited by 16 publications

References 1 publication

Electron Densities and Alkali Atoms in Exoplanet Atmospheres

Electron Densities and Alkali Atoms in Exoplanet Atmospheres

Significant non-adiabatic effects of the K(4s²S) + H₂ reaction

Dynamics and Kinetics of Metal Atoms in the Gas Phase

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Collisional deactivation of potassium (52PJ) by molecular hydrogen. Identification of the primary quenching channel

Cited by 16 publications

References 1 publication

Electron Densities and Alkali Atoms in Exoplanet Atmospheres

Electron Densities and Alkali Atoms in Exoplanet Atmospheres

Significant non-adiabatic effects of the K(4s2S) + H2 reaction

Dynamics and Kinetics of Metal Atoms in the Gas Phase

Contact Info

Product

Resources

About

Significant non-adiabatic effects of the K(4s²S) + H₂ reaction