Home > 研究動態

Insight into the Dinuclear {Fe(NO)2}10 {Fe(NO)2}10 and Mononuclear {Fe(NO)2}10 Dinitrosyliron Complexes


Abstract Image

The reversible redox transformations [(NO)2Fe(StBu)2]? [Fe(μ-StBu)(NO)2]22– [Fe(μ-StBu)(NO)2]2 [Fe(μ-StBu)(NO)2]2 and [cation][(NO)2Fe(SEt)2] [cation]2[(NO)2Fe(SEt)2] (cation = K+-18-crown-6 ether) are demonstrated. The countercation of the {Fe(NO)2}9 dinitrosyliron complexes (DNICs) functions to control the formation of the {Fe(NO)2}10{Fe(NO)2}10 dianionic reduced Roussin’s red ester (RRE) [PPN]2[Fe(μ-SR)(NO)2]2 or the {Fe(NO)2}10 dianionic reduced monomeric DNIC [K+-18-crown-6 ether]2[(NO)2Fe(SR)2] upon reduction of the {Fe(NO)2}9 DNICs [cation][(NO)2Fe(SR)2] (cation = PPN+, K+-18-crown-6 ether; R = alkyl). The binding preference of ligands [OPh]?/[SR]? toward the {Fe(NO)2}10{Fe(NO)2}10 motif of dianionic reduced RRE follows the ligand-displacement series [SR]? > [OPh]?. Compared to the Fe K-edge preedge energy falling within the range of 7113.6–7113.8 eV for the dinuclear {Fe(NO)2}9{Fe(NO)2}9 DNICs and 7113.4–7113.8 eV for the mononuclear {Fe(NO)2}9 DNICs, the {Fe(NO)2}10 dianionic reduced monomeric DNICs and the {Fe(NO)2}10{Fe(NO)2}10 dianionic reduced RREs containing S/O/N-ligation modes display the characteristic preedge energy 7113.1–7113.3 eV, which may be adopted to probe the formation of the EPR-silent {Fe(NO)2}10-{Fe(NO)2}10 dianionic reduced RREs and {Fe(NO)2}10 dianionic reduced monomeric DNICs in biology. In addition to the characteristic Fe/S K-edge preedge energy, the IR νNO spectra may also be adopted to characterize and discriminate [(NO)2Fe(μ-StBu)]2 [IR νNO 1809 vw, 1778 s, 1753 s cm–1 (KBr)], [Fe(μ-StBu)(NO)2]2 [IR νNO 1674 s, 1651 s cm–1 (KBr)], [Fe(μ-StBu)(NO)2]22– [IR νNO 1637 m, 1613 s, 1578 s, 1567 s cm–1 (KBr)], and [K-18-crown-6 ether]2[(NO)2Fe(SEt)2] [IR νNO 1604 s, 1560 s cm–1 (KBr)].The research was conducted at the NSRRC beamline 16A1 and 17C1.

S.-W. Yeh, C.-W. Lin, Y.-W. Li, I.-J. Hsu, C.-H. Chen, L.-Y. Jang, J.-F. Lee, and W.-F. Liaw

Inorg. Chem. 51 , 4076 (2012)