Hakey Brett M, Darmon Jonathan M, Akhmedov Novruz G, Petersen Jeffrey L, Milsmann Carsten
C. Eugene Bennett Department of Chemistry , West Virginia University , 100 Prospect Street , Morgantown , West Virginia 26506 , United States.
Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States.
Inorg Chem. 2019 Aug 19;58(16):11028-11042. doi: 10.1021/acs.inorgchem.9b01560. Epub 2019 Jul 31.
Reaction of (PDP)Fe(thf) (HPDP = 2,6-bis(5-(2,4,6-trimethylphenyl)-3-phenyl-1H-pyrrol-2-yl)pyridine) with organic azides has been studied. The identity of the azide substituent had a profound impact on the transformation type and nature of the observed products. Reaction with aromatic -tolyl azide, NTol, resulted in exclusive formation of the corresponding iron tetrazene complex (PDP)Fe(NTol). In contrast, the use of bulky 1-adamantyl azide led to clean intramolecular C-H amination of one of the benzylic C-H bonds of a mesityl substituent on the pyridine dipyrrolide, PDP, supporting ligand. The smaller aliphatic substituent in benzyl azide allowed for the isolation of two different compounds from distinct reaction pathways. One product is the result of double C-H amination of the PDP ligand via nitrene transfer, while the second one contains a dibenzyltetrazene and a benzaldimine ligand. All isolated complexes were characterized using a combination of X-ray crystallography, solid state magnetic susceptibility measurements, H NMR and Fe Mössbauer spectroscopy, and density functional theory (DFT), and their electronic structures were elucidated. Potential electronic structures for putative iron(IV) imido or iron(III) imidyl radical complexes were explored via DFT calculations.
研究了(PDP)Fe(thf)（HPDP = 2,6-双(5-(2,4,6-三甲基苯基)-3-苯基-1H-吡咯-2-基)吡啶）与有机叠氮化物的反应。叠氮取代基的特性对所观察到的产物的转化类型和性质有深远影响。与芳基对甲苯基叠氮化物NTol反应，专一性地生成相应的铁四氮烯配合物(PDP)Fe(NTol)。相反，使用体积较大的1-金刚烷基叠氮化物导致吡啶二吡咯配体PDP上的均三甲苯基取代基的一个苄基C-H键发生分子内C-H胺化反应。苄基叠氮化物中较小的脂肪族取代基使得可以从不同的反应途径分离出两种不同的化合物。一种产物是通过氮宾转移对PDP配体进行双C-H胺化反应的结果，而另一种产物含有二苄基四氮烯和苯甲醛亚胺配体。所有分离出的配合物都通过X射线晶体学、固态磁化率测量、1H NMR和Fe穆斯堡尔光谱以及密度泛函理论(DFT)相结合的方法进行了表征，并阐明了它们的电子结构。通过DFT计算探索了假定的铁(IV)亚胺基或铁(III)亚胺基自由基配合物的潜在电子结构。
