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

该项目的总体策略包括使用NHC/CAAC-膦酰亚胺和NHC/CAAC-膦酰亚胺合成铁和钴络合物，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，设想分离出几种新的络合物。特别是双核或三核配合物的N2活化可以被视为本研究的主要目标。尽管最近流行的NHC-膦酰亚胺和NHC-膦酰亚胺化物，只有少数相应的铁或钴配合物被建立。此外，许多二氮-铁和二氮-钴络合物依赖于膦基配体的事实，关于活性变化的这种亚膦基或亚膦基络合物的研究当然是令人感兴趣的。与（NHC）P-配体类似，也可以使用相关的CAAC配体，因为过渡金属络合物中的（CAAC）P-配体尚未报道。该工作计划是按照以下目标沿着制定的：-NHC/CAAC-膦酰亚胺作为配体以及NHC/CAAC-膦酰亚胺部分的转移试剂的合成和表征-带有NHC/CAAC-亚膦和-膦酰亚胺配体的低价铁和钴络合物的合成和表征-这些络合物在还原条件下关于二氮固定和二氮活化的研究-关于氨和N-C/Si键形成的潜在二氮络合物的研究

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