Gas-phase Ion-molecule Interactions involving Atom Transfer; Limitations of the Orbiting Theory in accounting for the Variation of Cross-section with Energy

Nature ◽  
1964 ◽  
Vol 202 (4934) ◽  
pp. 795-797 ◽  
Author(s):  
J. B. HOMER ◽  
R. S. LEHRLE ◽  
J. C. ROBB ◽  
D. W. THOMAS
Keyword(s):  
Gas Phase ◽  
Cross Section ◽  
Atom Transfer ◽  
Molecule Interactions ◽  
Gas Phase Ion

Gas-phase ion-molecule interactions in a collision reaction cell with QQQ-ICP-MS: Investigations with N2O as the reaction gas

2021 ◽  
pp. 106309
Author(s):  
Khadouja Harouaka ◽  
Caleb Allen ◽  
Eric Bylaska ◽  
Richard M. Cox ◽  
Greg Eiden ◽  
...  
Keyword(s):  
Gas Phase ◽  
Reaction Cell ◽  
Icp Ms ◽  
Molecule Interactions ◽  
Gas Phase Ion

An investigation of the ion–molecule interactions of protonated glycine with ammonia by high pressure mass spectrometry and ab initio calculations

2005 ◽  
Vol 83 (11) ◽  
pp. 1978-1993 ◽  
Author(s):  
Ronghu Wu ◽  
Terry B McMahon
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Potential Energy ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Gas Phase ◽  
Energy Surface ◽  
Stable Isomer ◽  
Molecule Interactions ◽  
Gas Phase Ion

The thermochemistry of gas-phase ion molecule interactions and the structures of various clusters between protonated glycine (GlyH+), glycine, and ammonia have been studied by high pressure mass spectrometry (HP-MS) and ab initio calculations. For the association reactions of GlyH+ with NH3, Gly(NH3)H+ with NH3, and (Gly)2H+ with NH3, the enthalpy changes experimentally determined are –23.2, –18.3, and –19.1 kcal mol–1 (1 cal = 4.184 J), respectively. For all clusters investigated, the measured binding enthalpies are in excellent agreement with those obtained from ab initio calculations at the B3LYP/6-311+G(d,p) level of theory. Different isomers of each of these clusters have been obtained and the corresponding binding energies have been computed. The potential energy surface for isomerization of the clusters of protonated glycine with ammonia has also been computed at the same level. For this cluster, the three most stable isomers all involve a proton transfer from protonated glycine to ammonia. According to the calculated potential energy surface, the barrier between GN4, the least stable isomer, and the most stable isomer (GN1) is 11.5 kcal mol–1 at 298 K. Thus, this isomerization will be facile given the exothermicity of the association reaction. Therefore, a statistical distribution of isomers will be present under thermal equilibrium conditions. Single point energy calculations at the MP2(full)/6-311++G(2d,2p)//B3LYP/6-311+G(d,p) level of theory reveal that the isomer GN2 in which glycine has a zwitterionic structure has the same energy as the most stable non-zwitterionic isomer GN1. NH4+ evidently may stabilize the zwitterionic structure of glycine. In contrast, N2H7+ and GlyH+ are not as effective in stabilizing the zwitterionic structure of glycine. This likely results from the more localized charge in NH4+ giving rise to stronger hydrogen bonds with the carboxylate moiety of zwitterionic glycine. This conjecture is supported by the computational results.Key words: high pressure mass spectrometry, glycine, gas-phase ion thermochemistry, ab initio calculations, cluster structure.

scholarly journals Reaction Roulette: Utilizing Elemental MS/MS for the Characterization of Gas Phase Ion-Molecule Interactions

2021 ◽  
Author(s):  
Khadouja Harouaka ◽  
Caleb Allen ◽  
Kali Melby ◽  
Eric Bylaska ◽  
Richard Cox ◽  
...  
Keyword(s):  
Gas Phase ◽  
Molecule Interactions ◽  
Gas Phase Ion

Reactivity Trends in the Gas Phase Addition of Acetylene to N-protonated Aryl Radical Cations

2020 ◽  
Author(s):  
Oisin Shiels ◽  
P. D. Kelly ◽  
Cameron C. Bright ◽  
Berwyck L. J. Poad ◽  
Stephen Blanksby ◽  
...  
Keyword(s):  
Gas Phase ◽  
Ion Trap ◽  
Radical Cations ◽  
Rate Coefficients ◽  
Similar Process ◽  
Ion Molecule Reactions ◽  
Aromatic Radicals ◽  
Polycyclic Aromatic ◽  
Gas Phase Ion ◽  
Type Radical

<div> <div> <div> <p>A key step in gas-phase polycyclic aromatic hydrocarbon (PAH) formation involves the addition of acetylene (or other alkyne) to σ-type aromatic radicals, with successive additions yielding more complex PAHs. A similar process can happen for N- containing aromatics. In cold diffuse environments, such as the interstellar medium, rates of radical addition may be enhanced when the σ-type radical is charged. This paper investigates the gas-phase ion-molecule reactions of acetylene with nine aromatic distonic σ-type radical cations derived from pyridinium (Pyr), anilinium (Anl) and benzonitrilium (Bzn) ions. Three isomers are studied in each case (radical sites at the ortho, meta and para positions). Using a room temperature ion trap, second-order rate coefficients, product branching ratios and reaction efficiencies are reported. </p> </div> </div> </div>

scholarly journals Triangular Rhodamine Triads and Their Intrinsic Photophysics Revealed from Gas‐Phase Ion Fluorescence Experiments

2021 ◽  
Author(s):  
Ying Zhao ◽  
Emma Rostal Sørensen ◽  
Thomas Toft Lindkvist ◽  
Christina Kjær ◽  
Mogens Brøndsted Nielsen ◽  
...  
Keyword(s):  
Gas Phase ◽  
Gas Phase Ion
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