Can Gas-Phase Radical/Neutral Reactions Account for Observed Abundances of Propynal within Dense Interstellar Clouds?

1995 ◽  
Vol 454 (2) ◽  
Author(s):  
Simon Petrie
Keyword(s):  
Gas Phase ◽  
Interstellar Clouds

Electronic Spectra of the Triacetylene Cation (HC6H+) and Protonated Triacetylene (HC6H2+) Tagged with Ar

2019 ◽  
Vol 72 (4) ◽  
pp. 260 ◽  
Author(s):  
Ugo Jacovella ◽  
Giel Muller ◽  
Katherine J. Catani ◽  
Nastasia I. Bartlett ◽  
Evan J. Bieske
Keyword(s):  
Electronic Spectrum ◽  
Gas Phase ◽  
Band System ◽  
Argon Atom ◽  
Planetary Atmospheres ◽  
Phase Spectrum ◽  
Tandem Mass ◽  
Interstellar Clouds ◽  
Combustion Processes ◽  
First Time

Polyacetylene cations (HC2nH+) play important roles in combustion processes and in the chemistry of planetary atmospheres and interstellar clouds. Here we report the electronic spectrum for the triacetylene cation (HC6H+) recorded over the 300–610nm range by photodissociating mass-selected ions tagged with argon atoms in a tandem mass spectrometer. The spectrum shows three band systems that are assigned to (origin transition 16665cm−1), (origin transition 23916cm−1), and (origin transition 29920cm−1). Although the band system is well known, the and band systems are observed for the first time in the gas phase. In addition, the electronic spectrum of the protonated triacteylene cation tagged with an argon atom (HC6-Ar) is reported, providing the first gas-phase spectrum for this species.

scholarly journals Molecular Formation in Hot Diffuse Clouds

1980 ◽  
Vol 87 ◽  
pp. 273-280
Author(s):  
A. Dalgarno
Keyword(s):  
Gas Phase ◽  
Interstellar Clouds ◽  
Gas Phase Chemistry ◽  
Molecular Formation ◽  
Phase Chemistry ◽  
Diffuse Clouds

A description is given of the processes of molecular formation and destruction in diffuse interstellar clouds and detailed models of the clouds lying towards ζ Ophiuchi, ζ Persei and o Persei are used to assess the validity of gas phase chemistry. Modifications that may arise from shock-heated regions are discussed.

Theoretical study on the gas phase reaction of CH2O + NH3: the formation of CH2O⋯NH3, NH2CH2OH, or CH2NH + H2O

2019 ◽  
Vol 21 (35) ◽  
pp. 19242-19251 ◽  
Author(s):  
Mohamad Akbar Ali
Keyword(s):  
Organic Chemistry ◽  
Gas Phase ◽  
Theoretical Study ◽  
Phase Reaction ◽  
Combustion Chemistry ◽  
Interstellar Clouds ◽  
Gas Phase Reaction

The gas phase reaction between CH2O and NH3 is an important reaction in cold interstellar clouds, combustion chemistry and organic chemistry.

scholarly journals Astrochemistry of Interstellar Clouds: II. Molecular Formation in a Contracting Cloud

1987 ◽  
Vol 120 ◽  
pp. 273-274
Author(s):  
M.A. El Shalaby ◽  
A. Aiad
Keyword(s):  
Gas Phase ◽  
Optical Depth ◽  
Chemical Reactions ◽  
Particle Density ◽  
Interstellar Cloud ◽  
Gas Phase Reactions ◽  
Interstellar Clouds ◽  
Continous Function ◽  
Molecular Formation ◽  
Self Gravity

The chemistry of an 667 Mo interstellar cloud was studied using 142 reactions for 40 species during the contraction under self gravity in two steps. At first the contraction is allowed without gas phase reactions untill certain optical depth is reached. Secondly, at this optical depth the chemical reactions are started for sufficient cycles in a time dependant scheme till only very small additionally changes in the abundances occur. The so obtained, relative abundances and coulmn densities for different species represent a continous function of the optical depths. The values arround τ=6.3 represent the observations for H2, H2+, H3+, OH, OH+, CH, CH+, CH2, CH2+, CH3+, H2O and H3O+. The region of τ between 1 and 5 i.e. of particle density between 4 102–6 103 is the preferable formation place for the majority of molecules.

scholarly journals Gas Phase Synthesis of Amino-, Cyano- and Nitroso-Compounds in Interstellar Clouds

1980 ◽  
Vol 87 ◽  
pp. 311-315
Author(s):  
Nigel G. Adams ◽  
David Smith
Keyword(s):  
Gas Phase ◽  
Laboratory Data ◽  
Nitroso Compounds ◽  
Phase Synthesis ◽  
Interstellar Clouds ◽  
Gas Phase Synthesis ◽  
Ion Molecule Reactions

From our laboratory data relating to several hundreds of ion-atom and ion-molecule reactions at thermal energies, we qualitatively describe probable chemical paths to the synthesis of amino-, cyano-and nitroso-compounds in interstellar clouds.

scholarly journals Evolutionary Models of Interstellar Chemistry

1992 ◽  
Vol 150 ◽  
pp. 205-210
Author(s):  
Sheo S. Prasad
Keyword(s):  
Gas Phase ◽  
Chemical Processes ◽  
Evolutionary Models ◽  
Evolutionary Perspective ◽  
Interstellar Chemistry ◽  
Interstellar Clouds ◽  
Dynamical Equilibrium ◽  
Chemical Models ◽  
Gas Phase Molecules ◽  
Fixed Condition

Evolutionary chemical models are ultimately unavoidable for a full understanding of interstellar clouds. They include not only the chemical processes but also the dynamical processes by which the modeled object came to be the way it is. From an evolutionary perspective, dark cores may be ephemeral objects and dynamical equilibrium an exception rather than norm. Evolutionary models have numerous advantages over “classical” fixed condition equilibrium models. They have the potential to provide more elegant explanations for the observed inter-cloud and intra-cloud chemical differences. The problem of the depletion of gas phase molecules by condensation onto the grain may also be less serious in evolutionary models. Hence, these models should be actively developed.

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