Design and preparation of dinitrogen complexes bearing an arsenic-containing ANA-type pincer ligand and their application to catalytic dinitogen fixation

利用二氮桥接二钼配合物和pnp型钳形配体作为催化剂，实现了一种将分子二氮直接转化为氨的新催化体系。因此，本研究关注的是使用含砷的ana型钳形配体，其中pnp型钳形配体中的膦取代arsines，因为已知arsines与磷化氢具有相似的配位模式，但也被认为比磷化氢更不愿氧化，空间体积更大，s-供体和p-受体更差。本文制备了一种新的含砷的单、二钼二氮配合物，并用x射线分析对其进行了表征。这些配合物在室温下用硫酸处理可提供一定量的氨。

A new catalytic system to convert molecular dinitrogen directly into ammonia has been achieved using a dinitrogen-bridged dimolybdenum complex with a PNP-type pincer ligand as a catalyst. Thus the use of an arsenic-containing ANA-type pincer ligand where phosphines in the PNP-type pincer ligand are substituted for arsines has been focuse on in this reserch, for arsines are known to have similar coordination modes to phosphines, but are also recognized to be more reluctant to oxidation, sterically bulkier, and poorer s-donors and p-acceptors compared to phosphines.Novel mono- and dimolybdenum-dinitrogen complexes bearing an arsenic-containing ANA-type pincer ligand are prepared and characterized by X-ray analyses. These complexes afford a stoichiometric amount of ammonia by treatment with sulfuric acid at room temperature.