Sellin Malte, Watson James D, Fischer Julia, Schmitt Manuel, Ball Graham E, Field Leslie D, Krossing Ingo
Institut für Anorganische und Analytische Chemie and Freiburg Materials Research Center FMF, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany.
School of Chemistry, University of New South Wales, Sydney, Sydney, NSW 2052, Australia.
J Am Chem Soc. 2025 Sep 24;147(38):35164-35171. doi: 10.1021/jacs.5c13214. Epub 2025 Sep 13.
Dinitrogen complexes are intermediates in nitrogen fixation. Until now, all isolated molecular dinitrogen complexes have relied on ancillary ligands that are net electron donors, yielding N ligands carrying a clear negative partial charge. Here, we present the synthesis, isolation, and characterization of the complex salt [Mn(CO)(η-N)][F(Al(OR))] (R = C(CF)) that resulted from the oxidation of Mn(CO) under a dinitrogen atmosphere in pentafluorobenzene solvent. The IR/Raman spectra reveal a high N frequency of 2301/2303 cm close to free N gas (2330 cm) that indicates little π-back-donation. QTAIM and CD-NOCV analyses show that the carbonyl ligands act as net acceptor ligands that induce the formation of an inversely polarized dinitrogen ligand with a +0.2 charge on the terminal atom that holds the potential to be susceptible to nucleophilic attack.
二氮配合物是固氮过程中的中间体。到目前为止，所有分离出的分子二氮配合物都依赖于作为净电子供体的辅助配体，从而产生带有明显负部分电荷的N配体。在此，我们展示了配合物盐[Mn(CO)(η-N)][F(Al(OR))]（R = C(CF)）的合成、分离和表征，该配合物盐是在五氟苯溶剂中，在二氮气氛下氧化Mn(CO)得到的。红外/拉曼光谱显示，其N频率高达2301/2303 cm，接近游离N气的频率（2330 cm），这表明几乎没有π-反馈给电子作用。量子拓扑原子理论（QTAIM）和电荷分解分析结合自然轨道（CD-NOCV）分析表明，羰基配体作为净受体配体，诱导形成了一种反向极化的二氮配体，其末端原子上带有+0.2的电荷，这使得该配体有可能易于受到亲核攻击。
