HAS-ELTE Laboratory Astrochemistry Lendület Research Group , Pázmány P. S. 1/a , Budapest 1117 , Hungary.
Laboratory of Molecular Spectroscopy, Institute of Chemistry , ELTE Eötvös Loránd University , Pázmány P. S. 1/a , Budapest 1117 , Hungary.
J Am Chem Soc. 2019 Jul 24;141(29):11614-11620. doi: 10.1021/jacs.9b04491. Epub 2019 Jul 11.
Formamide (HNCHO) is the smallest molecule possessing the biologically important amide bond. Recent interstellar observations have shown a strong correlation between the abundance of formamide and isocyanic acid (HNCO), indicating that they are likely to be chemically related, but no experiment or theory explains this correlation satisfactorily. We performed H + HNCHO reactions in a -hydrogen quantum-solid matrix host and identified production of HNCO and HNCO from hydrogen-abstraction reactions. We identified also DNCO, DNCO, HDNCO, and HDNCHO from the reaction H + DNCHO, indicating the presence of hydrogen-addition reactions of DNCO and HDNCO. From the observed temporal profiles of HNCHO, HNCO, HNCO, and their deuterium isotopologues, we showed that a dual-cycle consisting of hydrogen abstraction and hydrogen addition can satisfactorily explain the quasi-equilibrium between HNCHO and HNCO and explain other previous experimental results. Furthermore, this mechanism also indicates that the catalytic formation of H from H atoms might occur in interstellar ice grains.
甲酰胺（HNCHO）是具有生物重要酰胺键的最小分子。最近的星际观测表明，甲酰胺和异氰酸（HNCO）的丰度之间存在很强的相关性，这表明它们可能在化学上有关联，但没有实验或理论能令人满意地解释这种相关性。我们在-氢量子固体基质宿主中进行了 H + HNCHO 反应，并通过氢原子提取反应确定了 HNCO 和 HNCO 的生成。我们还从反应 H + DNCHO 中鉴定出了 DNCO、DNCO、HDNCO 和 HDNCHO，表明 DNCO 和 HDNCO 存在氢加成反应。从观察到的 HNCHO、HNCO、HNCO 及其氘同位素的时间分布曲线，我们表明由氢原子提取和氢加成组成的双循环可以令人满意地解释 HNCHO 和 HNCO 之间的准平衡，并解释其他先前的实验结果。此外，该机制还表明，H 从 H 原子的催化形成可能发生在星际冰粒中。
Zotero 插件