Determining and Understanding N-H Bond Strengths in Synthetic Nitrogen Fixation Cycles
Determining and Understanding N-H Bond Strengths in Synthetic Nitrogen Fixation Cycles
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DOI：
10.1007/3418_2016_8
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发表时间：
2017-01-01
期刊：
影响因子：
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通讯作者：
Chirik, Paul J.
中科院分区：
文献类型：
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作者：
Bezdek, Mate J.;Pappas, Iraklis;Chirik, Paul J.
利用分子催化剂将大气中的二氮固定为氨一直是均相催化和合成化学中的一个长期挑战。解决这一问题的新方法可能会为这一重要的工业化合物提供更节能和碳中和的途径。尽管氨、酰胺、酰亚胺和二氮烯配体在配位化学中无处不在，但很少有热力学数据可用于理解具有这些含氮片段的分子中的N-H键强度。本文介绍了一个概述的N-H键解离自由能的测定在各种化合物有关固氮氨的计算和实验方法。金属的氧化态，辅助配体和身份的氮供体的影响突出。未来的设计的分子系统减少二氮的影响进行了讨论。
The fixation of atmospheric dinitrogen to ammonia using molecular catalysts has been a long-standing challenge in homogeneous catalysis and synthetic chemistry. New approaches to this problem may offer more energy-efficient and carbon-neutral routes to this important industrial compound. Despite the ubiquity of ammine, amide, imide and diazenide ligands in coordination chemistry, little thermodynamic data is available for understanding N-H bond strengths in molecules bearing these nitrogenous fragments. This article presents an overview of both computational and experimental approaches for the determination of N-H bond dissociation free energies in a variety of compounds relevant to nitrogen fixation to ammonia. The influence of metal oxidation state, ancillary ligand and identity of the nitrogen donor are highlighted. Implications for future design of molecular systems for the reduction of dinitrogen are discussed.