Qian Bao-Chen, Wang Xiao, Wang Qi, Zhu Xiao-Qing, Shen Guang-Bin
College of Medical Engineering, Jining Medical University Jining Shandong 272000 P. R. China
The State Key Laboratory of Elemento-Organic Chemistry, Department of Chemistry, Nankai University Tianjin 300071 China
RSC Adv. 2024 Jan 2;14(1):222-232. doi: 10.1039/d3ra08022f.
N-heterocycles are important chemical hydrogen-storage materials, and the acceptorless dehydrogenation and hydrogenation of N-heterocycles as organic hydrogen carriers have been widely studied, with the main focus on the catalyst synthesis and design, investigation of the redox mechanisms, and extension of substrate scope. In this work, the Gibbs free energies of the dehydrogenation of pre-aromatic N-heterocycles (YH) and the hydrogenation of aromatic N-heterocycles (Y), , Δ(YH) and Δ(Y), were derived by constructing thermodynamic cycles using Hess' law. The thermodynamic abilities for the acceptorless dehydrogenation and hydrogenation of 78 pre-aromatic N-heterocycles (YH) and related 78 aromatic N-heterocycles (Y) were well evaluated and discussed in acetonitrile. Moreover, the applications of the two thermodynamic parameters in identifying pre-aromatic N-heterocycles possessing reversible dehydrogenation and hydrogenation properties and the selection of the pre-aromatic N-heterocyclic hydrogen reductants in catalytic hydrogenation were considered and are discussed in detail. Undoubtedly, this work focuses on two new thermodynamic parameters of pre-aromatic and aromatic N-heterocycles, namely Δ(YH) and Δ(Y), which are important supplements to our previous work to offer precise insights into the chemical hydrogen storage and hydrogenation reactions of pre-aromatic and aromatic N-heterocycles.
N-杂环是重要的化学储氢材料，作为有机氢载体的N-杂环的无受体脱氢和加氢反应已得到广泛研究，主要集中在催化剂的合成与设计、氧化还原机理研究以及底物范围的拓展。在本工作中，通过利用赫斯定律构建热力学循环，推导了前芳香族N-杂环（YH）脱氢和芳香族N-杂环（Y）加氢的吉布斯自由能，即Δ(YH)和Δ(Y)。在乙腈中对78种前芳香族N-杂环（YH）和相关的78种芳香族N-杂环（Y）的无受体脱氢和加氢的热力学能力进行了很好的评估和讨论。此外，还考虑了这两个热力学参数在识别具有可逆脱氢和加氢性质的前芳香族N-杂环以及催化加氢中前芳香族N-杂环氢还原剂选择方面的应用，并进行了详细讨论。毫无疑问，这项工作聚焦于前芳香族和芳香族N-杂环的两个新的热力学参数，即Δ(YH)和Δ(Y)，这是对我们之前工作的重要补充，能够为前芳香族和芳香族N-杂环的化学储氢和加氢反应提供精确的见解。
