Evaluating molecular cobalt complexes for the conversion of N2 to NH3.
Evaluating molecular cobalt complexes for the conversion of N2 to NH3.
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DOI：
10.1021/acs.inorgchem.5b00645
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发表时间：
2015-10-05
影响因子：
4.6
通讯作者：
Peters JC
中科院分区：
文献类型：
--
作者：
Del Castillo TJ;Thompson NB;Suess DL;Ung G;Peters JC
尽管几十年来一直受到关注，但用于用质子和电子将N2还原为NH3的明确定义的分子催化剂仍然非常罕见，并且目前仅限于以Mo或Fe为特征的系统。该报告详细介绍了分子Co络合物的合成，该分子Co络合物通过用质子和电子直接还原N2产生超化学计量产率的NH3（每个Co-N2前体> 200%NH3）。虽然本文报道的NH3产率与先前描述的Fe和Mo体系相比是适度的，但它们暗示其它金属可能作为分子N2还原催化剂是可行的。此外，特征三（膦）硼烷Co-N2络合物与结构上相关的Co-N2和Fe-N2物质的比较显示潜在的前催化剂的N2还原性能是多么显著敏感。这些研究使得能够考虑可能与N2转化活性相关的结构和电子效应，包括π-碱度、电荷状态和几何柔性。
Well-defined molecular catalysts for the reduction of N2 to NH3 with protons and electrons remain very rare despite decades of interest, and are currently limited to systems featuring Mo or Fe. This report details the synthesis of a molecular Co complex that generates superstoichiometric yields of NH3 (>200% NH3 per Co-N2 precursor) via the direct reduction of N2 with protons and electrons. While the NH3 yields reported herein are modest by comparison to previously described Fe and Mo systems, they intimate that other metals are likely to be viable as molecular N2 reduction catalysts. Additionally, comparison of the featured tris(phosphine)borane Co-N2 complex with structurally related Co-N2 and Fe-N2 species shows how remarkably sensitive the N2 reduction performance of potential pre-catalysts are. These studies enable consideration of structural and electronic effects that are likely relevant to N2 conversion activity, including π-basicity, charge state, and geometric flexibility.