High-pressure photoionization mass spectrometry. Effect of internal energy and density on the ion-molecule reactions occurring in methyl, dimethyl, and trimethylamine

1973 ◽  
Vol 5 (2) ◽  
pp. 177-186 ◽  
Author(s):  
L. Hellner ◽  
L. W. Sieck
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Internal Energy ◽  
Photoionization Mass Spectrometry ◽  
Ion Molecule Reactions

Ion–molecule reactions in dimethylsulfoxide by high pressure photoionization mass spectrometry

1980 ◽  
Vol 58 (4) ◽  
pp. 376-380 ◽  
Author(s):  
John A. Stone ◽  
Margaret S. Lin
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Photon Energy ◽  
Rate Constant ◽  
Pressure Range ◽  
Low Pressure ◽  
Photoionization Mass Spectrometry ◽  
Ion Molecule Reactions

Dimethylsulfoxide (DMSO) has been photoionized at 10.0 and 11.7 eV over the pressure range 0.3–210 mTorr. The rate constant for the disappearance of DMSO+ is 1.0 × 10−9 cm3 molecule−1 s−1, independent of photon energy. The major products at low pressure are CH3SO(CH3SO)CH3+ and CH3SOHCH3+ while at high pressure the ion series (DMSO)nH+ predominates with n ≤ 5. In experiments with mixtures of DMSO and water or methanol very little mixed solvation of the proton was observed although isotopic D/H exchange between D2O and (DMSO)2H+ is facile.

The internal energy of sputtered glycerol molecules, determined by photoionization mass spectrometry

1988 ◽  
Vol 88 (9) ◽  
pp. 5314-5322 ◽  
Author(s):  
R. Hoogerbrugge ◽  
M. Bobeldijk ◽  
P. G. Kistemaker ◽  
J. Los
Keyword(s):  
Mass Spectrometry ◽  
Internal Energy ◽  
Photoionization Mass Spectrometry

scholarly journals Ab initio dynamics and photoionization mass spectrometry reveal ion–molecule pathways from ionized acetylene clusters to benzene cation

2017 ◽  
Vol 114 (21) ◽  
pp. E4125-E4133 ◽  
Author(s):  
Tamar Stein ◽  
Biswajit Bandyopadhyay ◽  
Tyler P. Troy ◽  
Yigang Fang ◽  
Oleg Kostko ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ab Initio ◽  
Internal Energy ◽  
Aromatic Ring ◽  
Growth Mechanism ◽  
Product Distribution ◽  
Ab Initio Molecular Dynamics ◽  
Unimolecular Decomposition ◽  
Photoionization Mass Spectrometry ◽  
Excess Internal Energy

The growth mechanism of hydrocarbons in ionizing environments, such as the interstellar medium (ISM), and some combustion conditions remains incompletely understood. Ab initio molecular dynamics (AIMD) simulations and molecular beam vacuum-UV (VUV) photoionization mass spectrometry experiments were performed to understand the ion–molecule growth mechanism of small acetylene clusters (up to hexamers). A dramatic dependence of product distribution on the ionization conditions is demonstrated experimentally and understood from simulations. The products change from reactive fragmentation products in a higher temperature, higher density gas regime toward a very cold collision-free cluster regime that is dominated by products whose empirical formula is (C2H2)n+, just like ionized acetylene clusters. The fragmentation products result from reactive ion–molecule collisions in a comparatively higher pressure and temperature regime followed by unimolecular decomposition. The isolated ionized clusters display rich dynamics that contain bonded C4H4+ and C6H6+ structures solvated with one or more neutral acetylene molecules. Such species contain large amounts (>2 eV) of excess internal energy. The role of the solvent acetylene molecules is to affect the barrier crossing dynamics in the potential energy surface (PES) between (C2H2)n+ isomers and provide evaporative cooling to dissipate the excess internal energy and stabilize products including the aromatic ring of the benzene cation. Formation of the benzene cation is demonstrated in AIMD simulations of acetylene clusters with n > 3, as well as other metastable C6H6+ isomers. These results suggest a path for aromatic ring formation in cold acetylene-rich environments such as parts of the ISM.

scholarly journals Direct time-resolved detection and quantification of key reactive intermediates in diethyl ether oxidation at T = 450–600 K

2020 ◽  
Vol 22 (42) ◽  
pp. 24649-24661
Author(s):  
Maria Demireva ◽  
Kendrew Au ◽  
Leonid Sheps
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Diethyl Ether ◽  
Vacuum Ultraviolet ◽  
Reactive Intermediates ◽  
Reaction Intermediates ◽  
Time Resolved ◽  
Photoionization Mass Spectrometry ◽  
Ionization Radiation ◽  
Detection And Quantification

High-pressure multiplexed photoionization mass spectrometry (MPIMS) with tunable vacuum ultraviolet (VUV) ionization radiation from the Lawrence Berkeley Labs Advanced Light Source is used to characterize and quantify key reaction intermediates in the oxidation of diethyl ether (DEE).

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