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-亚膦和NHC/CAAc-亚膦合成铁和钴的络合物，并随后检查它们在还原条件下固定氮的能力。通过将申请者在NHC主族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，可以设想分离出几个新的络合物。特别是二核或三核配合物对氮气的活化作用可以作为本研究的主要目标。尽管最近NHC-膦化合物和NHC-膦化合物很受欢迎，但只有很少的相应的铁或钴配合物被建立。此外，许多二氮-铁和钴的配合物依赖于基于膦的配体，因此研究这种基于膦或膦的配合物的活性变化当然是很有意义的。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。工作计划是按照以下目标制定的：-作为NHC/CAAc-亚膦配体和转移试剂的NHC/CaAc-亚膦化合物的合成和表征-含有NHC/CAAc-亚膦和-亚膦配体的低价铁和钴配合物的合成和表征-关于还原条件下氮素固定和氮氮激活的这些络合物的研究-关于氨和N-C/Si键形成的潜在的二氮络合物的研究。

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.