Sulfur K-edge XAS and DFT calculations on [Fe4S4]2+ clusters:: Effects of H-bonding and structural distortion on covalency and spin topology

被引：33

作者：

Dey, A

Roche, CL

Walters, MA ^{[1
]}

Hodgson, KO

Hedman, B

Solomon, EI

机构：

[1] NYU, Dept Chem, New York, NY 10003 USA

[2] Stanford Univ, Dept Chem, Stanford, CA 94305 USA

[3] Stanford Synchrotron Radiat Lab, SLAC, Menlo Pk, CA 94302 USA

来源：

INORGANIC CHEMISTRY | 2005年 / 44卷 / 23期

关键词：

D O I：

10.1021/ic050981m

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

Sulfur K-edge X-ray absorption spectroscopy of a hydrogen-bonded elongated [Fe4S4](2+) cube is reported. The data show that this synthetic cube is less covalent than a normal compressed cube with no hydrogen bonding. DFT calculations reveal that the observed difference in electronic structure has significant contributions from both the cluster distortion and from hydrogen bonding. The elongated and compressed Fe4S4 structures are found to have different spin topologies (i.e., orientation of the delocalized Fe2S2 subclusters which are antiferromagnetically coupled to each other). It is suggested that the H-bonding interaction with the counterion does not contribute to the cluster elongation. A magneto-structural correlation is developed for the Fe4S4 cube that is used to identify the redoxactive Fe2S2 subdusters in active sites of HiPIP and ferredoxin proteins involving these clusters.

引用

页码：8349 / 8354

页数：6

共 36 条

[1]

AGARWAL BK, 1979, XRAY SPECTROSCOPY, P276

[2]

[Anonymous], [No title captured], DOI DOI 10.1016/0021-9991(92)90277-6

[3] Sulfur K-edge X-ray absorption spectroscopy of 2Fe-2S ferredoxin:: Covalency of the oxidized and reduced 2Fe forms and comparison to model complexes [J].