Department of Chemistry, University of Hawaii at Manoa, 2545 McCarthy Mall, Honolulu, HI 96822, USA.
W. M. Keck Laboratory in Astrochemistry, University of Hawaii at Manoa, 2545 McCarthy Mall, Honolulu, HI 96822, USA.
Chemphyschem. 2021 May 17;22(10):985-994. doi: 10.1002/cphc.202100064. Epub 2021 Apr 19.
Ices of acetylene (C H ) and ammonia (NH ) were irradiated with energetic electrons to simulate interstellar ices processed by galactic cosmic rays in order to investigate the formation of C H N isomers. Supported by quantum chemical calculations, experiments detected product molecules as they sublime from the ices using photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS). Isotopically-labeled ices confirmed the C H N assignments while photon energies of 8.81 eV, 9.80 eV, and 10.49 eV were utilized to discriminate isomers based on their known ionization energies. Results indicate the formation of ethynamine (HCCNH ) and 2H-azirine (c-H CCHN) in the irradiated C H :NH ices, and the energetics of their formation mechanisms are discussed. These findings suggest that these two isomers can form in interstellar ices and, upon sublimation during the hot core phase, could be detected using radio astronomy.
乙炔（C2H2）和氨（NH3）冰在高能电子的辐照下模拟了星际冰被银河宇宙射线处理的过程，以研究 C2H3N 异构体的形成。在量子化学计算的支持下，实验使用光致电离反射飞行时间质谱（PI-ReTOF-MS）检测了当产物分子从冰升华时的产物分子。同位素标记的冰证实了 C2H3N 的分配，而 8.81 eV、9.80 eV 和 10.49 eV 的光子能量被用于根据已知的电离能来区分异构体。结果表明，在辐照的 C2H：NH3冰中形成了乙撑亚胺（HCCNH）和 2H-氮丙啶（c-H CCHN），并讨论了它们形成机制的能量学。这些发现表明，这两种异构体可以在星际冰中形成，并且在热核相中升华时，可能可以通过射电天文学检测到。
