Kleimeier N Fabian, Eckhardt André K, Kaiser Ralf I
Department of Chemistry, University of Hawaii at Ma̅noa, Honolulu, Hawaii 96822, United States.
W. M. Keck Laboratory in Astrochemistry, University of Hawaii at Ma̅noa, Honolulu, Hawaii 96822, United States.
J Am Chem Soc. 2021 Sep 1;143(34):14009-14018. doi: 10.1021/jacs.1c07978. Epub 2021 Aug 18.
Glycolaldehyde is considered the entry point in the aqueous prebiotic formose (Butlerow) reaction although it mainly exists in its unreactive hydrated form in aqueous solution. The characterization of the more reactive nucleophilic enol form under interstellar conditions has remained elusive to date. Here we report on the identification of glycolaldehyde enol (1,2-ethenediol, HOHC═CHOH) in low temperature methanol-bearing ices at temperatures as low as 5 K. Exploiting isotope labeling and isomer-selective photoionization coupled with reflectron time-of-flight mass spectrometry, our results unravel distinct reaction pathways to 1,2-ethenediol, thus demonstrating the kinetic stability, availability for prebiotic sugar formation, and potential detectability in deep space.
乙醇醛被认为是水相益生元甲醛聚糖（布特列洛夫）反应的起始点，尽管它在水溶液中主要以无反应活性的水合形式存在。迄今为止，在星际条件下更具反应活性的亲核烯醇形式的表征仍然难以捉摸。在此，我们报告了在低至5 K的温度下，在含甲醇的低温冰中鉴定出乙醇醛烯醇（1,2 - 乙烯二醇，HOHC═CHOH）。利用同位素标记和异构体选择性光离子化结合反射式飞行时间质谱，我们的结果揭示了生成1,2 - 乙烯二醇的不同反应途径，从而证明了其动力学稳定性、益生元糖形成的可能性以及在深空中潜在的可探测性。
