Dinitrogen fixation with low-valent iron and cobalt complexes bearing phosphinidenides

该项目的总体战略包括使用NHC/ caac -膦酸酯和NHC/ caac -膦酸酯合成铁和钴配合物，并随后检查它们在还原条件下固定二氮的能力。通过将申请人在nhc主基团元素化学方面的专业知识与主办机构在铁和钴化学方面的经验相结合，设想了几种新型配合物的分离。特别是二核或三核配合物的N2活化可以视为本研究的主要目标。尽管近年来nhc -膦酸盐和nhc -膦酸盐很受欢迎，但相应的铁或钴配合物却很少。此外，事实上，许多二氮-铁和-钴配合物依赖于膦基配体，研究这些膦或膦基配合物的活性变化当然是有趣的。与（NHC）P -配体类似，也可以使用相关的CAAC配体，因为过渡金属配合物中的（CAAC）P -配体尚未见报道。工作方案是根据以下目标制定的：- NHC/ caac -膦酸苷作为配体的合成和表征以及NHC/ caac -膦酸苷部分的转移试剂-含NHC/ caac -膦酸苷和-膦酸苷配体的低价铁和钴配合物的合成和表征-这些配合物在还原条件下对二氮固定和二氮活化的研究-对氨和N-C /Si键形成的潜在二氮配合物的研究

The general strategy for this project involves the use of NHC/CAAC-phosphinidenes and NHC/CAAC-phosphinidenidesfor the synthesis of iron and cobalt complexes and the subsequent examination of their abilities to fixate dinitrogen under reductive conditions. By merging the expertise of the applicant in NHC-main group element chemistry with the experience of the host institution in iron- and cobalt-chemistry, the isolation of several novel complexes are envisaged. Especially the N2 activation with di- or- tri-nuclear complexes can be regarded as the main target of this investigation. Despite the recent popularity of NHC-phosphinidenes and NHC-phosphinidenides, only few corresponding iron or cobalt complexes were established. Furthermore, the fact that many dinitrogen-iron and -cobalt complexes rely on phosphane based ligands, the investigation of such phosphinidene or phosphinidenide based complexes regarding the change of activity is certainly of interest. In analogy to the (NHC)P– ligand, related CAAC ligands can also be used, since (CAAC)P– ligands in transition metal complexes are not reported yet. The work program is formulated along the following objectives: -Synthesis and characterization of NHC/CAAC-phosphinidenes as ligands as well as transfer reagents for the NHC/CAAC-phosphinidenide moieties -Synthesis and characterization of low valent iron- and cobalt-complexes bearing NHC/CAAC-phosphinidene and -phosphinidenide ligands -Investigation of these complexes regarding dinitrogen fixation and dinitrogen activation under reductive conditions -Investigation of the potential dinitrogen complexes regarding ammonia and N–C/Si bond formation.