24286-05-3Relevant academic research and scientific papers
Formation of Glyoxylic Acid in Interstellar Ices: A Key Entry Point for Prebiotic Chemistry
Eckhardt, André K.,Bergantini, Alexandre,Singh, Santosh K.,Schreiner, Peter R.,Kaiser, Ralf I.
supporting information, p. 5663 - 5667 (2019/03/29)
With nearly 200 molecules detected in interstellar and circumstellar environments, the identification of the biologically relevant α-keto carboxylic acid, glyoxylic acid (HCOCOOH), is still elusive. Herein, the formation of glyoxylic acid via cosmic-ray driven, non-equilibrium chemistry in polar interstellar ices of carbon monoxide (CO) and water (H2O) at 5 K via barrierless recombination of formyl (HCO) and hydroxycarbonyl radicals (HOCO) is reported. In temperature-programmed desorption experiments, the subliming neutral molecules were selectively photoionized and identified based on the ionization energy and distinct mass-to-charge ratios in combination with isotopically labeled experiments exploiting reflectron time-of-flight mass spectrometry. These studies unravel a key reaction path to glyoxylic acid, an organic molecule formed in interstellar ices before subliming in star-forming regions like SgrB2(N), thus providing a critical entry point to prebiotic organic synthesis.
Formation of complex organic molecules in methanol and methanol-carbon monoxide ices exposed to ionizing radiation - A combined FTIR and reflectron time-of-flight mass spectrometry study
Maity, Surajit,Kaiser, Ralf I.,Jones, Brant M.
, p. 3081 - 3114 (2015/02/05)
The radiation induced chemical processing of methanol and methanol-carbon monoxide ices at 5.5 K exposed to ionizing radiation in the form of energetic electrons and subsequent temperature programmed desorption is reported in this study. The endogenous formation of complex organic molecules was monitored online and in situ via infrared spectroscopy in the solid state and post irradiation with temperature programmed desorption (TPD) using highly sensitive reflectron time-of-flight (ReTOF) mass spectrometry coupled with single photoionization at 10.49 eV. Infrared spectroscopic analysis of the processed ice systems resulted in the identification of simple molecules including the hydroxymethyl radical (CH2OH), formyl radical (HCO), methane (CH4), formaldehyde (H2CO), carbon dioxide (CO2), ethylene glycol (HOCH2CH2OH), glycolaldehyde (HOCH2CHO), methyl formate (HCOOCH3), and ketene (H2CCO). In addition, ReTOF mass spectrometry of subliming molecules following temperature programmed desorption definitely identified several closed shell C/H/O bearing organics including ketene (H2CCO), acetaldehyde (CH3COH), ethanol (C2H5OH), dimethyl ether (CH3OCH3), glyoxal (HCOCOH), glycolaldehyde (HOCH2CHO), ethene-1,2-diol (HOCHCHOH), ethylene glycol (HOCH2CH2OH), methoxy methanol (CH3OCH2OH) and glycerol (CH2OHCHOHCH2OH) in the processed ice systems. Additionally, an abundant amount of molecules yet to be specifically identified were observed sublimating from the irradiated ices including isomers with the formula C3H(x=4,6,8)O, C4H(x=8,10)O, C3H(x=4,6,8)O2, C4H(x=6,8)O2, C3H(x=4,6)O3, C4H8O3, C4H(x=4,6,8)O4, C5H(x=6,8)O4 and C5H(x=6,8)O5. The last group of molecules containing four to five oxygen atoms observed sublimating from the processed ice samples include an astrobiologically important class of sugars relevant to RNA, phospholipids and energy storage. Experiments are currently being designed to elucidate their chemical structure. In addition, several reaction pathways were identified in the irradiated ices of mixed isotopes based upon the results of both in situ FTIR analysis and TPD ReTOF gas phase analysis. In general, the results of this study provide crucial information on the formation of a variety of classes of organics including alcohols, ketones, aldehydes, esters, ethers, and sugars within the bulk ices upon exposure to ionizing radiation that are relevant to the molecular clouds within the interstellar medium.
Photo-tautomerization of acetaldehyde to vinyl alcohol: A potential route to tropospheric acids
Andrews, Duncan U.,Heazlewood, Brianna R.,Maccarone, Alan T.,Conroy, Trent,Payne, Richard J.,Jordan, Meredith J. T.,Kable, Scott H.
, p. 1203 - 1206 (2012/10/29)
Current atmospheric models underestimate the production of organic acids in the troposphere. We report a detailed kinetic model of the photochemistry of acetaldehyde (ethanal) under tropospheric conditions. The rate constants are benchmarked to collision-free experiments, where extensive photo-isomerization is observed upon irradiation with actinic ultraviolet radiation (310 to 330 nanometers). The model quantitatively reproduces the experiments and shows unequivocally that keto-enol photo-tautomerization, forming vinyl alcohol (ethenol), is the crucial first step. When collisions at atmospheric pressure are included, the model quantitatively reproduces previously reported quantum yields for photodissociation at all pressures and wavelengths. The model also predicts that 21 ± 4% of the initially excited acetaldehyde forms stable vinyl alcohol, a known precursor to organic acid formation, which may help to account for the production of organic acids in the troposphere.
