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Published on: October 18, 2019
High-Spin Iron(I) and Iron(0) Dinitrogen Complexes Supported by N-Heterocyclic Carbene Ligands
Zhenwu Ouyang1, Jun Cheng1, Lingling Li2
1State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, P. R. China.
Abstract:
The use of 1,3-dicyclohexylimidazol-2-ylidene (ICy) as ligand has enabled the preparation of the high-spin tetrahedral iron(I)- and iron(0)-N2 complexes, namely [(ICy)3 Fe(N2 )][BPh4 ] (1) and [(ICy)3 Fe(N2 )] (2), the electronic structures of which have been established by various spectroscopic characterization and DFT calculations. The frequency of the N-N stretching resonance of the iron(0)-N2 complex is the lowest among the reported terminal N2 complexes of iron, signifying the beneficial roles of strongly σ-donating ligands in combination with the high-spin low-valent iron center in promoting N2 -activation. The iron(0)-N2 complex can convert reversibly to the low-spin iron(II)-N2 hydride complex [(ICy)2 (ICy')Fe(N2 )(H)] (4).
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