Photochemistry of the Dinitrosyl Iron Complex [S5Fe(NO)2]- Leading to Reversible Formation of [S5Fe(
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- 作者：Ming-Li Tsai ; Chiao-Chun Chen ; I-Jui Hsu ; Shyue-Chu Ke ; Chung-Hung Hsieh ; Kuo-An Chiang ; Gene-Hsiang Lee ; Yu Wang ; Jin-Ming Chen ; Jyh-Fu Lee ; and Wen-Feng Liaw
- 刊名：Inorganic Chemistry
- 出版年：2004
- 出版时间：August 9, 2004
- 年：2004
- 卷：43
- 期：16
- 页码：5159 - 5167
- 全文大小：190K
- 年卷期：v.43,no.16(August 9, 2004)
- ISSN：1520-510X
文摘
The reaction of [PPN][Fe(CO)3(NO)] and S8 in a 1:1 molar ratio in THF proceeded to give the dinitrosyl ironcomplex [PPN][S5Fe(NO)2] (1) and the known [PPN]2[S5Fe(
-S)2FeS5] (2). EPR signals of g values gz = 2.0148,gx = 2.0270, and gy = 2.0485 at 77 K confirmed the existence of the unpaired electron in compound 1. Thetemperature-dependent magnetic moment of complex 1 indicates that the ground state is one unpaired electronwith (St, SL) = (1/2, 1) at very low temperature (St is the total spin quantum number of the system; SL is the sumof the spin quantum numbers of two NO ligands). The O K-edge absorptions of complex 1 and [(NO)Fe(S2CNEt2)2]at 532.1 and 532.5 eV are assigned to the transition of 1s 
*(NO) and 1s *(NO+), respectively. For theelectronic structure of the {Fe(NO)2} core, DFT calculations, magnetic susceptibility measurement, EPR, and FeK-/L-edge XAS spectroscopy of complex 1 lead to a description of {Fe1+(
NO)2}9. [2Fe-2S] cluster 2 treated withnitric oxide in THF shows that cluster 2 is transformed into the dinitrosyl iron complex 1 identified by IR, UV-vis,and X-ray diffraction analysis. The reaction may be reversed by the photolysis of the THF solution of 1 in thepresence of the NO-accepting reagent [(C4H8O)Fe(S,S-C6H4)2]- to reform 2. This result demonstrates a successfulbiomimetic reaction cycle of the degradation and reassembly of [2Fe-2S] cluster [S5Fe(-S)2FeS5]2- relevant tothe repair of nitric oxide-modified [2Fe-2S] ferredoxin by cysteine desulfurase and L-cysteine in vitro.
-S)2FeS5] (2). EPR signals of g values gz = 2.0148,gx = 2.0270, and gy = 2.0485 at 77 K confirmed the existence of the unpaired electron in compound 1. Thetemperature-dependent magnetic moment of complex 1 indicates that the ground state is one unpaired electronwith (St, SL) = (1/2, 1) at very low temperature (St is the total spin quantum number of the system; SL is the sumof the spin quantum numbers of two NO ligands). The O K-edge absorptions of complex 1 and [(NO)Fe(S2CNEt2)2]at 532.1 and 532.5 eV are assigned to the transition of 1s *(NO) and 1s *(NO+), respectively. For theelectronic structure of the {Fe(NO)2} core, DFT calculations, magnetic susceptibility measurement, EPR, and FeK-/L-edge XAS spectroscopy of complex 1 lead to a description of {Fe1+(NO)2}9. [2Fe-2S] cluster 2 treated withnitric oxide in THF shows that cluster 2 is transformed into the dinitrosyl iron complex 1 identified by IR, UV-vis,and X-ray diffraction analysis. The reaction may be reversed by the photolysis of the THF solution of 1 in thepresence of the NO-accepting reagent [(C4H8O)Fe(S,S-C6H4)2]- to reform 2. This result demonstrates a successfulbiomimetic reaction cycle of the degradation and reassembly of [2Fe-2S] cluster [S5Fe(-S)2FeS5]2- relevant tothe repair of nitric oxide-modified [2Fe-2S] ferredoxin by cysteine desulfurase and L-cysteine in vitro.© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |