920-42-3Relevant articles and documents
Isotope Exchange Reaction of Formate with Molecular Hydrogen on Ni(110) by IRAS
Yamakata, Akira,Kubota, Jun,Kondo, Junko N.,Domen, Kazunari,Hirose, Chiaki
, p. 18177 - 18182 (1996)
Kinetics of the CH/CD isotope exchange reaction of formate (HCOO(a)/DCOO(a)) on Ni(110) with gaseous D2/H2 was investigated below the decomposition temperature (360 K) by infrared reflection absorption spectroscopy (IRAS).The apparent activation energies of HCOO(a) -> DCOO (a) and DCOO(a) -> HCOO(a) reactions were derived as 52 +/- 5 and 58 +/- 5 kJ*mol-1, respectively.A half-order dependence of the reaction rate on hydrogen pressure was observed, suggesting that the rate-determining step was the reaction of the adsorbed formate with reversibly adsorbed hydrogen atom The reaction of HCOO(a) with D2 was 2.1 +/- 0.3 times faster than that of DCOO(a) with H2 at 300 K, and the origin of the isotope effect is discussed.
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.
Reductive transformation of CO2: Fluoride-catalyzed reactions with waste silicon-based reducing agents
Motokura, Ken,Naijo, Masaki,Yamaguchi, Sho,Miyaji, Akimitsu,Baba, Toshihide
, p. 434 - 439 (2017/04/06)
CO2 is one of the most important “renewable” carbon sources. To transform CO2 to useful organic compounds, we examined the reactivity of two model silicon-based “waste” materials, disilanes and metallic Si powder, as reducing agents. In these reactions, fluoride salts were found to be active catalysts: CO2 was converted to formic acid at atmospheric pressure in the presence of H2O as a proton source and the silicon-based reducing reagents. Based on in-situ NMR and kinetics analyses, a hydrosilane and penta-coordinate Si species are proposed as the reaction intermediate and active species, respectively.
Precision measurement of the quadrupole coupling and chemical shift tensors of the deuterons in α-calcium formate
Schmitt, Heike,Zimmermann,Koerner,Stumber,Meinel,Haeberlen
, p. 65 - 77 (2007/10/03)
Using calcium formate, α-Ca(DCOO)2, as a test sample, we explore how precisely deuteron quadrupole coupling (QC) and chemical shift (CS) tensors Q and σ can currently be measured. The error limits, ±0:09 kHz for the components of Q and ±0:06 ppm for those of σ, are at least three times lower than in any comparable previous experiment. The concept of a new receiver is described. A signal/noise ratio of 100 is realized in single-shot FT spectra. The measurement strategies and a detailed error analysis are presented. The precision of the measurement of Q is limited by the uncertainty of the rotation angles of the sample and that of σ by the uncertainty of the phase correction parameters needed in FT spectroscopy. With a 4-sigma confidence, it is demonstrated for the first time that the unique QC tensor direction of a deuteron attached to a carbon deviates from the bond direction; the deviation found is (1:2±0:3°). Evidence is provided for intermolecular QC contributions. In terms of Q, their size is roughly 4 kHz. The deuteron QC tensors in α-Ca(DCOO)2 (two independent deuteron sites) are remarkable in three respects. For deuterons attached to sp2 carbons, first, the asymmetry factors η and, second, the quadrupole coupling constants CQ, are unusually small, η1 = 0:018; η2 = 0:011, and CQ1 = (151:27±0:06) kHz, CQ2 = (154:09±0:06) kHz. Third, the principal direction associated with the largest negative QC tensor component lies in and not, as usual, perpendicular to the molecular plane. A rationalization is provided for these observations. The CS tensors obtained are in quantitative agreement with the results of an earlier, less precise, line-narrowing multiple-pulse study of α-Ca(HCOO)2. The assignment proposed in that work is confirmed. Finally we argue that a further 10-fold increase of the measurement precision of deuteron QC tensors, and a 2-fold increase of that of CS tensors, should be possible. We indicate the measures that need to be taken.