ChemInform Abstract: Gas-Phase Organic Ion Molecule Reaction Chemistry

The gas-phase photolysis of 2-methyl-1,3-butadiene has been investigated using krypton (123.6 nm) resonance radiation. The observed neutral products of the primary decomposition were vinylacetylene, ethylene, acetylene, methylacetylene, propylene, allene, 2-methy-1-buten-3-yne, pentatriene/1-penten-3-yne, 1,3-butadiene, 2-butyne and butatriene, listed in decreasing order of concentration. There was also evidence of the presence of several radical fragments: CH2/CH3, C2H3, C3H3, and C4H5. Quantum yields for each of the products were determined in the photolysis of 2-methyl-1,3-butadiene, performed both in the presence and the absence of additives. Nitric oxide and oxygen were employed as radical scavengers, while hydrogen sulfide and hydrogen iodide were used as radical interceptors. Twelve primary, neutral molecule, reaction channels were proposed and the quantum efficiency assigned for each. The ionization efficiency of 2-methyl-1,3-butadiene was established as n = 0.55 at 10.03 eV. No products formed exclusively via an ion–molecule pathway were identified and therefore the fate of the C5H8+ ion was not determined.

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Gas phase ion–molecule reactions of dimethylsulphoxide

Canadian Journal of Chemistry ◽

10.1139/v78-382 ◽

1978 ◽

Vol 56 (17) ◽

pp. 2324-2330 ◽

Cited By ~ 11

Author(s):

John Edward Fulford ◽

Joseph Wayne Dupuis ◽

Raymond Evans March

Keyword(s):

Gas Phase ◽

Ambient Pressure ◽

Reaction Chamber ◽

Ion Trapping ◽

Ion Chemistry ◽

Gas Phase Ion Chemistry ◽

Molecule Reaction ◽

Ion Molecule Reactions ◽

Ion Storage ◽

Gas Phase Ion

The gas phase ion-chemistry of dimethylsulphoxide (DMSO) and deuterated dimethylsulphoxide (DMSO-d6) has been examined using a quadrupole ion store (QUISTOR) as an ion–molecule reaction chamber. The QUISTOR results are compared with those obtained by ion trapping and high pressure mass spectrometry as reported by other workers. The performance of the QUISTOR demonstrates the versatility of the technique for ion–molecule reaction studies with variation of ambient pressure and duration of ion storage.

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Gas-phase reactions of silicon ion (Si+ with ammonia and the amines (CH3)xNH3-x(X = 1-3): possible ion-molecule reaction pathways toward SiH, SiCH, SiNH, SiCH3, SiNCH3, and H2SiNH

Journal of the American Chemical Society ◽

10.1021/ja00216a010 ◽

1988 ◽

Vol 110 (8) ◽

pp. 2396-2399 ◽

Cited By ~ 32

Author(s):

S. Wlodek ◽

Diethard K. Bohme

Keyword(s):

Gas Phase ◽

Reaction Pathways ◽

Gas Phase Reactions ◽

Molecule Reaction

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The formation of urea in space

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731610 ◽

2018 ◽

Vol 610 ◽

pp. A26 ◽

Cited By ~ 7

Author(s):

Flavio Siro Brigiano ◽

Yannick Jeanvoine ◽

Antonio Largo ◽

Riccardo Spezia

Keyword(s):

Activation Energy ◽

Interstellar Medium ◽

Gas Phase ◽

Organic Molecules ◽

Peptide Bond ◽

Biological Molecules ◽

Gas Phase Reactions ◽

Molecule Reaction ◽

Quantum Chemistry Calculations ◽

Highly Correlated

Context. Many organic molecules have been observed in the interstellar medium thanks to advances in radioastronomy, and very recently the presence of urea was also suggested. While those molecules were observed, it is not clear what the mechanisms responsible to their formation are. In fact, if gas-phase reactions are responsible, they should occur through barrierless mechanisms (or with very low barriers). In the past, mechanisms for the formation of different organic molecules were studied, providing only in a few cases energetic conditions favorable to a synthesis at very low temperature. A particularly intriguing class of such molecules are those containing one N–C–O peptide bond, which could be a building block for the formation of biological molecules. Urea is a particular case because two nitrogen atoms are linked to the C–O moiety. Thus, motivated also by the recent tentative observation of urea, we have considered the synthetic pathways responsible to its formation. Aims. We have studied the possibility of forming urea in the gas phase via different kinds of bi-molecular reactions: ion-molecule, neutral, and radical. In particular we have focused on the activation energy of these reactions in order to find possible reactants that could be responsible for to barrierless (or very low energy) pathways. Methods. We have used very accurate, highly correlated quantum chemistry calculations to locate and characterize the reaction pathways in terms of minima and transition states connecting reactants to products. Results. Most of the reactions considered have an activation energy that is too high; but the ion-molecule reaction between NH2OHNH2OH2+ and formamide is not too high. These reactants could be responsible not only for the formation of urea but also of isocyanic acid, which is an organic molecule also observed in the interstellar medium.

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