论文标题
甲氨酸作为星际介质中亚胺的关键先驱：propargylimine的情况
Methanimine as a key precursor of imines in the interstellar medium: the case of propargylimine
论文作者
论文摘要
为最近检测到的propgylimine分子提出了气相形成途径。与其他亚胺（例如氰基胺）类似，在甲氨酸（Ch $ _2 $ nh}）中添加反应性自由基（C $ _2 $ h）也会在跨天然培养基的恶劣条件下开放反应通道。可以在C $ H_2 $ NH + C $ _2 $ H反应中形成三个可能的异构体：Z-和E-Propargylimine（Z-，E-PGIM）以及N- Ethynyl-Methanimine（N-Emim）。对于这两种PGIM物种，计算的全球速率系数在20-300 K温度范围内几乎是恒定的，并且订单为2-3 $ \ times $ 10 $^{ - 10} $ cm $^3 $分子$^{ - 1} $ s $ s $ s $^{ - 1} $，而N- emim的n-emim大约是两个级数。假设两个异构体的破坏率相等，这些结果意味着[z]/[e] $ \ sim $ 1.5的PGIM的丰度比率仅在观察数据方面被略微低估。
A gas-phase formation route is proposed for the recently detected propargylimine molecule. In analogy to other imines, such as cyanomethanimine, the addition of a reactive radical (C$_2$H in the present case) to methanimine (CH$_2$NH}) leads to reaction channels open also in the harsh conditions of the interstellar medium. Three possible isomers can be formed in the C$H_2$NH + C$_2$H reaction: Z- and E-propargylimine (Z-,E-PGIM) as well as N-ethynyl-methanimine (N-EMIM). For both PGIM species, the computed global rate coefficient is nearly constant in the 20-300 K temperature range, and of the order of 2-3 $\times$ 10$^{-10}$ cm$^3$ molecule$^{-1}$ s$^{-1}$, while that for N-EMIM is about two orders of magnitude smaller. Assuming equal destruction rates for the two isomers, these results imply an abundance ratio for PGIM of [Z]/[E] $\sim$ 1.5, which is only slightly underestimated with respect to the observational datum.
