A convenient route to synthetic analogues of the oxidized form of high-potential iron-sulfur proteins.
An amide-bound [Fe4S4](3+) cluster, [Fe4S4{N(SiMe3)2}4](-) (1), was found to serve as a convenient precursor for synthetic analogues of the oxidized form of high-potential iron-sulfur proteins. Treatment of 1 with 4 equiv of bulky thiols led to replacement of the amide ligands with thiolates, giving rise to a series of [Fe4S4(SR)4](-) clusters (R = Dmp (2a), Tbt (2b), Eind (2c), Dxp (2d), Dpp (2e); Dmp = 2,6-di(mesityl)phenyl, Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl, Eind = 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl, Dxp = 2,6-di(m-xylyl)phenyl, Dpp = 2,6-diphenylphenyl). These clusters were characterized by the mass spectrum, the EPR spectrum, and X-ray crystallography. The redox potentials of the [Fe4S4](3+/2+) couple, -0.82 V (2a), -0.86 V (2b), -0.84 V (2c), -0.74 V (2d), and -0.63 V (2e) vs Ag/Ag(+) in THF, are significantly more negative than that of [Fe4S4(SPh)4](-/2-) (-0.21 V).
Department of Chemistry, Graduate School of Science, and Research Center for Materials Science, Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
Kazuki
K
Tanifuji
Norihiro
N
Yamada
Tomoyuki
T
Tajima
Takahiro
T
Sasamori
Norihiro
N
Tokitoh
Tsukasa
T
Matsuo
Kohei
K
Tamao
Yasuhiro
Y
Ohki
Kazuyuki
K
Tatsumi
D000577:Amides / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007501:Iron / Q000737:chemistry*; D007506:Iron-Sulfur Proteins / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry*
D000577:Amides; D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; C007943:high potential iron-sulfur protein; D013455:Sulfur; D007501:Iron