Bernstein M P, Sandford S A, Allamandola L J, Gillette J S, Clemett S J, Zare R N
NASA-Ames Research Center, Mail Stop 245-6, Moffett Field, CA 94035-1000, USA.
Science. 1999 Feb 19;283(5405):1135-8. doi: 10.1126/science.283.5405.1135.
Polycyclic aromatic hydrocarbons (PAHs) in water ice were exposed to ultraviolet (UV) radiation under astrophysical conditions, and the products were analyzed by infrared spectroscopy and mass spectrometry. Peripheral carbon atoms were oxidized, producing aromatic alcohols, ketones, and ethers, and reduced, producing partially hydrogenated aromatic hydrocarbons, molecules that account for the interstellar 3.4-micrometer emission feature. These classes of compounds are all present in carbonaceous meteorites. Hydrogen and deuterium atoms exchange readily between the PAHs and the ice, which may explain the deuterium enrichments found in certain meteoritic molecules. This work has important implications for extraterrestrial organics in biogenesis.
水冰中的多环芳烃（PAHs）在天体物理条件下受到紫外线（UV）辐射，产物通过红外光谱和质谱进行分析。外围碳原子被氧化，生成芳醇、酮和醚；同时也会被还原，生成部分氢化的芳烃，这些分子构成了星际3.4微米发射特征。这些化合物类别都存在于碳质陨石中。氢原子和氘原子很容易在多环芳烃和冰之间交换，这可能解释了在某些陨石分子中发现的氘富集现象。这项工作对外源有机物的生物起源具有重要意义。
