On Earth and beyond, organic chemistry often occurs in the presence of water within environments that deviate drastically from ambient conditions (25 °C and 1 bar). Accurately predicting aqueous organic reaction pathways is crucial toward understanding planetary scale processes such as the cycling of elements crucial for life (e.g., carbon and nitrogen). Advanced thermodynamic modeling can be utilized to determine the favorability of various organic reactions based on geologically relevant ranges of temperature and pressure, as well as compositional variables (e.g., pH). However, data that would otherwise allow for a diversity of organic compounds and environmental conditions to be modeled are sparse and rarely tested with experiments, particularly with regard to organic-nitrogen compounds. In this work, we develop a framework to estimate thermodynamic properties at ambient conditions that can then be extrapolated across ranges of temperature and pressure for aqueous primary, secondary, and tertiary amines and aminiums (protonated amines), specifically those structures containing linear alkyl chains and benzyl functional groups. We also performed hydrothermal experiments (250 °C, ∼40 bar) involving reactions of methylamines to test our resulting thermodynamic models, and we compare our models for other alkylamines and benzylamines to previous empirical measurements from the literature. Specifically, we use existing thermodynamic data along with our estimates at ambient conditions in combination with a variety of existing extrapolation methods related to the revised Helgeson-Kirkham-Flowers (HKF) equations of state to generate temperature- and pressure-dependent predictions of acid dissociation constants (i.e., p values) that strongly agree with previous empirical measurements. We use similar methods to predict product distributions for reactions involving primary, secondary, and tertiary amines/aminiums, as well as ammonia/ammonium and corresponding alcohols whose collective distributions depend on reversible substitution reactions. Our predictions are in good agreement with our experimental results involving the methylamine reaction system as well as previous experiments involving the benzylamine reaction system, for which we also produced thermodynamic estimates involving benzyl alcohol. The agreement between independent theoretical predictions and experimental measurements suggests that our estimated properties can be applied to modeling amine chemistry in other experimental and natural aqueous systems that range in temperature and pressure, providing new tools for planetary exploration.

中文翻译：

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通过实验测量验证了含水伯、仲和叔烷基胺、苄胺及其相应的铵在温度和压力下的热力学性质估计

在地球及其他地方，有机化学通常发生在与环境条件（25 °C 和 1 bar）截然不同的环境中存在水的情况下。准确预测水性有机反应途径对于理解行星尺度的过程至关重要，例如对生命至关重要的元素（例如碳和氮）的循环。先进的热力学模型可用于根据地质相关的温度和压力范围以及成分变量（例如 pH）确定各种有机反应的有利性。然而，能够对多种有机化合物和环境条件进行建模的数据很少，并且很少通过实验进行测试，特别是关于有机氮化合物。在这项工作中，我们开发了一个框架来估计环境条件下的热力学性质，然后可以在温度和压力范围内推断含水伯胺、仲胺和叔胺和胺（质子化胺）的热力学性质，特别是那些含有直链烷基链和苄基官能团。我们还进行了涉及甲胺反应的水热实验（250°C，~40 bar），以测试我们所得的热力学模型，并将我们的其他烷基胺和苄胺模型与之前文献中的经验测量进行比较。具体来说，我们使用现有的热力学数据以及我们对环境条件的估计，结合与修订后的 Helgeson-Kirkham-Flowers (HKF) 状态方程相关的各种现有外推方法，以生成与温度和压力相关的酸解离预测与之前的经验测量结果非常一致的常数（即 p 值）。我们使用类似的方法来预测涉及伯、仲和叔胺/铵，以及氨/铵和相应醇的反应的产物分布，其集体分布取决于可逆取代反应。我们的预测与我们涉及甲胺反应系统的实验结果以及之前涉及苯甲胺反应系统的实验结果非常吻合，为此我们还进行了涉及苯甲醇的热力学估计。独立理论预测和实验测量之间的一致性表明，我们估计的特性可以应用于模拟其他实验和天然水系统中温度和压力范围内的胺化学，为行星探索提供新工具。