Results 1 to 10 of about 58,021 (177)

On the Presence of Metallofullerenes in Fullerene-rich Circumstellar Envelopes [PDF]

The Astrophysical Journal, 2022
The presence of neutral C _60 fullerenes in circumstellar environments has been firmly established by astronomical observations as well as laboratory experiments and quantum-chemistry calculations. However, the large variations observed in the C _60 17.4
R. Barzaga, D. A. García-Hernández, S. Díaz-Tendero, SeyedAbdolreza Sadjadi, A. Manchado, M. Alcami   +5 more
doaj   +2 more sources

Small Carbon Chains In Circumstellar Envelopes [PDF]

, 2014
Observations of carbon-rich circumstellar envelopes were made using the Phoenix spectrograph on the Gemini South telescope to determine the abundance of small carbon chain molecules.
Peter Bernath, Kenneth Hinkle, Hinkle, K., Bernath, P. F., Robert Hargreaves, Hargreaves, R. J., Hargreaves, Robert J.   +6 more
core   +2 more sources

AGB Stars and Their Circumstellar Envelopes. I. the VULCAN Code

Universe, 2021
The interplay between AGB interiors and their outermost layers, where molecules and dust form, is a problem of high complexity. As a consequence, physical processes like mass loss, which depend on the chemistry of the circumstellar envelope, are often ...
Sergio Cristallo, Luciano Piersanti, David Gobrecht, Lucio Crivellari, Ambra Nanni   +4 more
doaj   +1 more source

Investigating Possible Dipole‐Bound States of Cyanopolyynes: the Case for the C5N− Anion Detected in Interstellar Space

ChemPhysChem, Volume 24, Issue 22, November 16, 2023., 2023
Can the radical C5N bind a free electron to form a dipole‐bound state? The answer is sought using multi‐reference ab initio quantum chemical methods. Abstract We present results of quantum structure calculations aimed at demonstrating the possible existence of dipole‐bound states (DBS) for the anion C5N- ${{\rm{C}}_5 {\rm{N}}^ - }$ , a species already ...
Stanka Jerosimić, Milan Milovanović, Marko Mitić, Roland Wester, Francesco A. Gianturco   +4 more
wiley   +1 more source

Kinetics of the tautomerization of thioimidic acids R−C(SH)NH → R−C(S)NH2: For R = H, F, HO, CN, NC, H2N, HC(O), HC(S), HC≡ C, CH3, CF3, H2C=CH, HOCH2, H2NCH2,CH3C(O), C2H5, (CH3)2CH, C6H5

International Journal of Chemical Kinetics, Volume 55, Issue 11, Page 731-742, November 2023., 2023
Abstract The kinetics of the tautomerization of thio‐imidic acids RC(SH)NH were determined at low (50–300 K) and high (500–1500 K) temperatures as R was varied to encompass mono‐ and diatomic species H, F, HO, NC, CN through H2N, HC(O), HC(S), HC≡ C, H3C, F3C, HOCH2, H2C=CH, CH3C(O), H2NCH2 and including ethyl, isopropyl and phenyl groups. The presence
Judith Würmel, John M. Simmie
wiley   +1 more source

Crescent-shaped Molecular Outflow from the Intermediate-mass Protostar DK Cha Revealed by ALMA

The Astrophysical Journal, 2023
We report on an Atacama Large Millimeter/submillimeter Array study of the Class I or II intermediate-mass protostar DK Cha in the Chamaeleon II region.
Naoto Harada, Kazuki Tokuda, Hayao Yamasaki, Asako Sato, Mitsuki Omura, Shingo Hirano, Toshikazu Onishi, Kengo Tachihara, Masahiro N. Machida   +8 more
doaj   +1 more source

Lutidyl Radical Photoelectron Spectra Reveal Additive Substituent Effects on Benzyl Derivatives’ Ionization Energy

ChemPhysChem, Volume 24, Issue 20, October 17, 2023., 2023
Threshold photoelectron spectroscopy with vacuum ultraviolet synchrotron radiation and quantum chemical calculations shed new light on the ionization energies of xylyl, picolyl and lutidyl radicals. N‐ and CH3‐substituent effects on the ionization energies of benzyl‐type reactive intermediates are found to be position‐dependent and additive.
Keisuke Kanayama, Christin Fernholz, Hisashi Nakamura, Kaoru Maruta, Andras Bodi, Patrick Hemberger   +5 more
wiley   +1 more source

Microlensing of circumstellar envelopes: II. emission lines from radial and azimuthal flow during fold caustic crossings [PDF]

, 2003
This paper examines the line profile evolution due to bulk motion in circumstellar envelopes during microlensing fold caustic crossing events. These events have recently been shown to be a sensitive probe of stellar surface brightness profiles, thus ...
Bryce, H.M., Hendry, M.A., Ignace, R., H. M. Bryce, M. A. Hendry, R. Ignace   +5 more
core   +1 more source

The Chemistry of the Cyaphide Ion

Angewandte Chemie International Edition, Volume 62, Issue 32, August 7, 2023., 2023
128 years after the erroneously assumed synthesis of sodium cyaphide, Na(CP), and 51 years after the definitive proof of the existence of HCP, the chemistry of the cyaphide anion has finally gained momentum. This review summarizes the chemistry of the cyaphide anion, (C≡P)−, from its beginnings to the state‐of‐the art.
Tim Görlich, Peter Coburger, Eric S. Yang, Jose M. Goicoechea, Hansjörg Grützmacher, Christian Müller   +5 more
wiley   +1 more source

Microlensing of circumstellar envelopes III. Line profiles from stellar winds in homologous expansion [PDF]

, 2006
This paper examines line profile evolution due to the linear expansion of circumstellar material obsverved during a microlensing event. This work extends our previous papers on emission line profile evolution from radial and azimuthal flow during point ...
Bryce, H.M., Hendry, M., Hendry, M.A., Bryce, H., Ignace, R., H. M. Bryce, Ignace, Richard, M. A. Hendry, R. Ignace   +8 more
core   +1 more source