In this study, we explore the potential for prebiotic chemistry in an extraterrestrial atmosphere through computational modeling of reactions involving hydrogen cyanide (HCN), hydrogen isocyanide (HNC), and ammonia (NH₃). Based on our automated reaction search, we identified several key intermediates, including formamidine (A), formaldehyde hydrazone (B), and methanediimine (C) which serve as precursors for a variety of complex organic compounds. Among the products, methanimine (P5) and guanidine (P22) have been proposed for their relevance to early biological activity. The calculated low activation barriers and exothermic nature of several reactions suggest the viability of these pathways in a cold extraterrestrial environment. Notably, the formation of molecules such as a triazole derivative (P18) and N-cyanoimidoformamide (P20), linked to biomarker cyanamide, underscores the potential for synthesizing biologically significant molecules. We provide theoretical roto-vibrational spectral parameters to assist in the experimental detection of these species, offering insights into the molecular complexity achievable in extraterrestrial atmosphere and contributing to our understanding of prebiotic chemistry in extraterrestrial environments.

中文翻译：

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外星大气中潜在的益生元途径：HCN 和 NH3 反应的计算探索

在这项研究中，我们通过对涉及氰化氢（HCN）、异氰化氢（HNC）和氨（NH ₃）的反应进行计算建模，探索了地外大气中生命起源前化学的潜力。基于我们的自动反应搜索，我们确定了几种关键中间体，包括甲脒 ( A )、甲醛腙 ( B ) 和甲烷二亚胺 ( C )，它们可作为多种复杂有机化合物的前体。在这些产品中，甲胺 ( P5 ) 和胍 ( P22 ) 因其与早期生物活性的相关性而被提出。计算出的低活化势垒和几个反应的放热性质表明这些途径在寒冷的地外环境中的可行性。值得注意的是，与生物标记氰胺连接的三唑衍生物（ P18）和N-氰基亚氨基甲酰胺（P20 ）等分子的形成强调了合成具有生物学意义的分子的潜力。我们提供理论旋转振动光谱参数来协助这些物种的实验检测，提供对地外大气中可实现的分子复杂性的见解，并有助于我们对地外环境中生命起源前化学的理解。