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.

An ICR mass spectrometry study of ion/molecule reactions between ethyl chloride and alkylamines

1991 ◽  
Vol 69 (2) ◽  
pp. 363-367
Author(s):  
Guoying Xu ◽  
Jan A. Herman
Keyword(s):  
Mass Spectrometry ◽  
Key Words ◽  
Rate Constant ◽  
Rate Constants ◽  
Ethyl Chloride ◽  
Ion Molecule Reactions ◽  
Mass Spectrometry Study ◽  
Ethyl Cation

Ion/molecule reactions in mixtures of ethyl chloride with C1–C4 alkylamines were studied by ICR mass spectrometry. Ethyl cation transfer to C1–C4 alkylamines proceeds mainly through diethylchloronium ions with rate constants ~3 × 10−10cm3 s−1. In the case of s-butylamine the corresponding rate constant is 0.5 × 10−10 cm3 s−1. Key words: ICR mass spectrometry, ion/molecule reactions, ethylchloride, methylamine, ethylamine, propylamines, butylamines

scholarly journals Photoionization mass spectrometry and modeling study of a low-pressure premixed flame of ethyl pentanoate (ethyl valerate)

2017 ◽  
Vol 36 (1) ◽  
pp. 1185-1192 ◽  
Author(s):  
D.A. Knyazkov ◽  
I.E. Gerasimov ◽  
N. Hansen ◽  
A.G. Shmakov ◽  
O.P. Korobeinichev
Keyword(s):  
Mass Spectrometry ◽  
Low Pressure ◽  
Premixed Flame ◽  
Photoionization Mass Spectrometry ◽  
Modeling Study

Phosphorescence Lifetime of S02 in the ã3B1 State at Low Pressure

1975 ◽  
Vol 53 (14) ◽  
pp. 2133-2139 ◽  
Author(s):  
J. Philip Briggs ◽  
Robert B. Caton ◽  
Michael J. Smith
Keyword(s):  
Decay Rate ◽  
Electronic State ◽  
Rate Constant ◽  
Pressure Range ◽  
Low Pressure ◽  
Nonradiative Relaxation ◽  
Phosphorescence Lifetime ◽  
Pressure Decay ◽  
Emission Decay ◽  
Spherical Container

The emission decay rate (inverse lifetime) of the optically-excited ã3B1 electronic state of SO2 vapor at approximately 25 °C has been measured in a 35 cm diameter spherical container over the pressure range 1 < P < 500 m Torr in pure SO2 and in mixtures of SO2 with He, Ar, or Xe. The Stern–Volmer rate constant for quenching by [Formula: see text]was determined to be (4.46 ± 0.11) × 108 1 mol−1 s−1, and the extrapolated, zero-pressure decay rate was calculated to be (3.75 ± 0.58) × 102 s−1. The latter quantity implies a considerably greater proportionate contribution by radiative, as opposed to nonradiative, relaxation of this state than has been reported previously.

Photolyse du méthyl-2-butène-1, du méthyl-3-butène-1 et du cis-pentène-2 à 174, 163 et 147 nm

1979 ◽  
Vol 57 (8) ◽  
pp. 863-869 ◽  
Author(s):  
Guy J. Collin ◽  
Hélène Deslauriers ◽  
Sylvain Auclair
Keyword(s):  
Double Bond ◽  
Photon Energy ◽  
Rate Constant ◽  
Pressure Effect ◽  
Low Pressure ◽  
Decomposition Process ◽  
Fragmentation Process ◽  
Quantum Yields ◽  
Methyl Radicals ◽  
Hydrogen Atoms

Photolysis of 2-methyl-1-butene (M2B1), cis-2-pentene (CP2), and 3-methyl-1-butene (M3B1) has been systematically studied at 163 nm. Pressure effect has been measured at 147, 163, and 174 nm. The main fragmentation process of the photoexcited olefine is the C—C split of the bond located in position β relative to the double bond:[Formula: see text] α-Methallyl radicals obtained in the M3B1 and CP2 photolysis decompose partly at low pressure, giving rise to the formation of 1,3-butadiene and hydrogen atoms. β-Methallyl radicals decompose also at low pressure into allene and methyl radicals. Butadiene and allene quantum yields follow the Stern–Volmer law, and this allows us to determine the ratio of the rate constant of dissociation relative to the rate constant of stabilization, kd/ks, through collision of the α- and β-methallyl radicals. From these values, we conclude that the excess of photon energy is not statistically distributed into the fragments, and that the decomposition process follows one (or several) particular law(s).

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