New H and H2 reactions with small hydrocarbon ions and their roles in benzene synthesis in dense interstellar clouds
New H and H2 reactions with small hydrocarbon ions and their roles in benzene synthesis in dense interstellar clouds
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DOI：
10.1086/306861
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发表时间：
1999-03-01
影响因子：
4.9
通讯作者：
Herbst, E
中科院分区：
文献类型：
--
作者：
McEwan, MJ;Scott, GBI;Herbst, E
本文综述了小分子烃类离子(CMHN+；In=1-6，n=0-9)与中性反应物H和H-2之间的正常和三体缔合离子-分子反应的最新知识。根据三体实验结果，计算和估算了选定的辐射缔合反应速率系数。一些正常的和辐射的缔合率系数已经被纳入我们的致密云星际化学的“新标准”模型中。我们发现，尽管H/H-2丰度比只有10(-4)，但H原子并没有提供足够的机制来增加CMHN+离子的饱和能级，在致密的星际云中有m>；3。新的模型结果特别表明，在稠密的云层中现在可以产生大量的碱性芳香族环状分子苯(c-C6H6)。
This paper summarizes the most recent knowledge concerning normal and three-body association ion-molecule reactions between small hydrocarbon ions (CmHn+; in = 1-6, n = 0-9) and the neutral reactants H and H-2. Selected radiative association reaction rate coefficients have been calculated and estimated based on three-body laboratory results. Some of the normal and radiative association rate coefficients have been incorporated into our "new standard" model of dense cloud interstellar chemistry. We find that atomic H provides an insufficiently appreciated mechanism to increase the level of saturation of CmHn+ ions, with m > 3 in dense interstellar clouds despite the fact that the H/H-2 abundance ratio is only 10(-4). New model results show in particular that a significant abundance of the basic aromatic cyclic molecule benzene (c-C6H6) can now be produced in dense clouds.