Results 11 to 20 of about 25,802 (223)

Is Phenylnitrene a Missing Link in the Formation of Polycyclic Aromatic Nitrogen Heterocycles? [PDF]

Angew Chem Int Ed Engl
A new formation pathway for polycyclic aromatic nitrogen heterocycles (PANHs) has been found. The reaction of phenylnitrene and the propargyl radical leads to quinoline, proving that nitrenes are suitable precursors for nitrogen incorporation mechanisms.
Arns R, McClish R, Hemberger P, Bodi A, Bouwman J, Kasper T, Schleier D.   +6 more
europepmc   +2 more sources

Prebiotic Synthesis and Isomerization in Interstellar Analog Ice: Glycinal, Acetamide, and Their Enol Tautomers

Angewandte Chemie, Volume 135, Issue 12, March 13, 2023., 2023
Out of the cold: Ammonia (NH3) and acetaldehyde (CH3CHO) are exposed to galactic cosmic ray proxies while frozen at 5 K to simulate the environment of an interstellar molecular cloud. Reactants undergo dissociation and radical recombination to produce glycinal (NH2CH2CHO) and acetamide (CH3CONH2) prior to tautomerization to 2‐aminoethenol (HOCHCHNH2 ...
Joshua H. Marks, Jia Wang, N. Fabian Kleimeier, Andrew M. Turner, André K. Eckhardt, Ralf I. Kaiser   +5 more
wiley   +2 more sources

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

Insights Into the Gas-Phase Structure and Internal Dynamics of Diphenylsilane: A Broadband Rotational Spectroscopy Study. [PDF]

Chemphyschem
The structure of diphenylsilane could be determined from the rotational spectra of all its singly substituted heavy atom isotopologues. A comparison with its oxygen analogue diphenylether revealed some interesting differences in the internal dynamics as well as in the gas‐phase structure.
Batra G, Schnell M.
europepmc   +2 more sources

Evaluating the GeoSnap 13‐μ$$ \mu $$m cutoff HgCdTe detector for mid‐IR ground‐based astronomy

Astronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023
Abstract New mid‐infrared HgCdTe (MCT) detector arrays developed in collaboration with Teledyne Imaging Sensors (TIS) have paved the way for improved 10‐μ$$ \mu $$m sensors for space‐ and ground‐based observatories. Building on the successful development of longwave HAWAII‐2RGs for space missions such as NEO Surveyor, we characterize the first 13‐μ ...
Jarron M. Leisenring, Dani Atkinson, Rory Bowens, Vincent Douence, William F. Hoffmann, Michael R. Meyer, John Auyeung, James Beletic, Mario S. Cabrera, Alexandra Z. Greenbaum, Philip Hinz, Derek Ives, William J. Forrest, Craig W. McMurtry, Judith L. Pipher, Eric Viges   +15 more
wiley   +1 more source

Substituent effects in the tautomerization of imidic acids R−C(OH)=NH → R−C(O)NH2: Kinetic implications for the formation of peptide bonds in the interstellar medium

International Journal of Chemical Kinetics, Volume 55, Issue 7, Page 381-391, July 2023., 2023
Abstract A number of amides, RC(O)NH2, have been detected spectroscopically in the space between the stars. Naturally the study of how these are formed is an important question on the path of chemical evolution from the elements C, H, N, O, P, … to life because the so‐called peptide‐bond −C(O)−NH− is a key linkage in poly‐amino acids or proteins.
Judith Würmel, John M. Simmie
wiley   +1 more source

Experimental Phase Function and Degree of Linear Polarization of Light Scattered by Hydrogenated Amorphous Carbon Circumstellar Dust Analogs

The Astrophysical Journal Supplement Series, 2023
Astronomical observations of the polarized intensity of scattered visible light have revealed the presence of dust envelopes around different types of evolved stars.
Juan Carlos Gómez Martín, Olga Muñoz, Julia Martikainen, Daniel Guirado, Isabel Tanarro, Ramón J. Peláez, Belén Maté, Miguel Jiménez-Redondo, Víctor J. Herrero, Marco Peiteado, Teresa Jardiel   +10 more
doaj   +1 more source

From Dust to Nanodust: Resolving Circumstellar Dust from the Colliding-wind Binary Wolf-Rayet 140

The Astrophysical Journal, 2023
Wolf-Rayet (WR) 140 is the archetypal periodic dust-forming colliding-wind binary that hosts a carbon-rich WR (WC) star and an O-star companion with an orbital period of 7.93 yr and an orbital eccentricity of 0.9.
Ryan M. Lau, Jason Wang, Matthew J. Hankins, Thayne Currie, Vincent Deo, Izumi Endo, Olivier Guyon, Yinuo Han, Anthony P. Jones, Nemanja Jovanovic, Julien Lozi, Anthony F. J. Moffat, Takashi Onaka, Garreth Ruane, Andreas A. C. Sander, Samaporn Tinyanont, Peter G. Tuthill, Gerd Weigelt, Peredur M. Williams, Sebastien Vievard   +19 more
doaj   +1 more source

Recent Advances in the Domain of Cyclic (Alkyl)(Amino) Carbenes

Chemistry – An Asian Journal, Volume 17, Issue 7, April 1, 2022., 2022
The present review highlights recent developments in the domain of cyclic (alkyl) (amino) carbenes with the emphasis on their applications in the field of catalysis, activation of small molecules, radical chemistry, organic light‐emitting diodes (OLEDs), medicinal chemistry, and single‐molecule magnets (SMMs). Abstract Isolation of cyclic (alkyl) amino
Saroj Kumar Kushvaha, Ankush Mishra, Herbert W. Roesky, Kartik Chandra Mondal   +3 more
wiley   +1 more source

Dust Echoes from Luminous Fast Blue Optical Transients

The Astrophysical Journal, 2023
Luminous fast blue optical transients (LFBOTs) such as AT2018cow form a rare class of engine-powered explosions of uncertain origin. A hallmark feature of these events is radio/millimeter synchrotron emission powered by the interaction of fast ≳0.1 c ...
Brian D. Metzger, Daniel A. Perley
doaj   +1 more source