Mass-selected ion–molecule reactions at very low temperatures. The CRESUS apparatus

1989 ◽  
Vol 85 (10) ◽  
pp. 1631-1641 ◽  
Author(s):  
Betrand R. Rowe ◽  
Jean-Baptiste Marquette ◽  
Christiane Rebrion
Keyword(s):  
Low Temperatures ◽  
Ion Molecule Reactions

Molecular-physics aspects of cold chemistry

2019 ◽  
pp. 82-141
Author(s):  
FrÉdÉric Merkt
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Molecular Physics ◽  
Exothermic Reactions ◽  
Langevin Model ◽  
Ion Molecule Reactions ◽  
Radiative Association ◽  
Association Reaction ◽  
Oppenheimer Approximation ◽  
General Aspects

Molecular-physics aspects of cold chemistry are introduced with the example of few-electron molecules. After a brief overview of general aspects of molecular physics, the solution of the molecular Schrödinger equation is presented based on the Born-Oppenheimer approximation and the subsequent evaluation of adiabatic, nonadiabatic, relativistic and radiative (QED) corrections. Low-temperature chemical phenomena are introduced with the example of ion-molecule reactions, using the classical Langevin model for barrier-free exothermic reactions as reference. Then, methods to generate cold few-electron molecules by supersonic-beam-deceleration methods such as Stark, Zeeman, and Rydberg-Stark decelerations are presented. Two astrophysically important reactions, the reaction between H2 and H2+ forming H3+ and H, a very fast reaction following Langevin-capture going over to quantum-Langevin capture at low temperature, and the radiative association reaction H+ + H forming H2+, a very slow reaction in which quantum effects (shape resonances) become important at low temperatures, are used to illustrate the concepts introduced.

scholarly journals Cover Picture: New Method to Study Ion-Molecule Reactions at Low Temperatures and Application to the H2++H2→H3++H Reaction (ChemPhysChem 22/2016)

ChemPhysChem ◽  
2016 ◽  
Vol 17 (22) ◽  
pp. 3578-3578 ◽  
Author(s):  
Pitt Allmendinger ◽  
Johannes Deiglmayr ◽  
Otto Schullian ◽  
Katharina Höveler ◽  
Josef A. Agner ◽  
...  
Keyword(s):  
Low Temperatures ◽  
New Method ◽  
Ion Molecule Reactions

scholarly journals New Method to Study Ion-Molecule Reactions at Low Temperatures and Application to the H2++H2→H3++H Reaction

ChemPhysChem ◽  
2016 ◽  
Vol 17 (22) ◽  
pp. 3580-3580
Author(s):  
Pitt Allmendinger ◽  
Johannes Deiglmayr ◽  
Otto Schullian ◽  
Katharina Höveler ◽  
Josef A. Agner ◽  
...  
Keyword(s):  
Low Temperatures ◽  
New Method ◽  
Ion Molecule Reactions

scholarly journals A mass-selective ion transfer line coupled with a uniform supersonic flow for studying ion–molecule reactions at low temperatures

2019 ◽  
Vol 150 (16) ◽  
pp. 164201 ◽  
Author(s):  
B. Joalland ◽  
N. Jamal-Eddine ◽  
D. Papanastasiou ◽  
A. Lekkas ◽  
S. Carles ◽  
...  
Keyword(s):  
Supersonic Flow ◽  
Low Temperatures ◽  
Ion Transfer ◽  
Ion Molecule Reactions ◽  
Transfer Line

Laboratory studies of isotope exchange in ion-neutral reactions: interstellar implications

1981 ◽  
Vol 303 (1480) ◽  
pp. 535-542 ◽  
Keyword(s):  
Low Temperatures ◽  
Isotope Exchange ◽  
Laboratory Data ◽  
Isotopic Ratios ◽  
Laboratory Studies ◽  
Terrestrial Environment ◽  
Interstellar Clouds ◽  
Ion Molecule Reactions ◽  
Significant Process ◽  
Molecule Interactions

The rare stable isotopes of several elements (e.g. D, 13 C and 15 N) have been detected in several interstellar molecules, and their abundance relative to the more common isotope is often enhanced above that in the solar-terrestrial environment. Important questions to answer are to what extent the isotopic ratios in the molecules are representative of those in the cloud matter as a whole, and whether fractionation of the heavier isotope into the molecules via ion—molecule interactions is a significant process. A laboratory study of isotope exchange in ion-molecule reactions has therefore been carried out, the results of which indicate that fractionation of heavy isotopes can occur very efficiently at low temperatures. Consideration is given in this paper to reactions in which H-D, 12 C - 13 C, 14 N - 15 N and 16 O - 18 O exchange occurs, and it is shown how better estimates of the electron density and the temperature in interstellar clouds have been obtained from these laboratory data.

scholarly journals Interstellar Molecules in Meteorites

1989 ◽  
Vol 135 ◽  
pp. 383-388
Author(s):  
J. F. Kerridge
Keyword(s):  
Solar System ◽  
Interstellar Medium ◽  
Low Temperatures ◽  
Isotopic Fractionation ◽  
Early Solar System ◽  
Interstellar Molecules ◽  
Interstellar Clouds ◽  
Ion Molecule Reactions ◽  
Chondritic Meteorites ◽  
Interstellar Material

Substantial enrichment of deuterium, D, in certain components of chondritic meteorites is interpreted as a record of isotopic fractionation during ion-molecule reactions at the very low temperatures characteristic of dense interstellar clouds. Whether those meteorites still contain the actual molecules that were synthesised in the presolar interstellar medium, or whether the interstellar material was recycled into a later generation of molecules within the early solar system is not known.

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