Super reduced Fe4S4 cluster of Balch's dithiolene series.
A super reduced Fe(4)S(4) cluster with a sulfur based radical, [NBu(4)](4)[Fe(3)(III)Fe(II)(μ(3)-S)(4)(mnt)(3)(6-)(mnt)(1-)˙](4-)˙, (1) (mnt, maleonitrile dithiolate) which evolves H(2)S gas on treatment with acid under ambient conditions has been synthesized and structurally characterized. The Fe-S distances in 1 are in the range 2.246-2.383 Å, in stark contrast to that of the known n = -2 member of the series based on the [Fe(4)(μ(3)-S)(4)(S(2)C(2)R(2))(4)](n) unit (R = CF(3), Ph) with Fe-S bond lengths of 2.149-2.186 Å. The EPR of 1 displays very weak signals at g, 4.03 and 2.38 along with a strong S-based radical EPR signal at g, 2.003 associated with five structured components tentatively assigned to hyperfine interaction arising out of the naturally abundant (57)Fe with <A> = 88 G. The EPR profile resembles the reduced Fe-S cluster of CO inhibited Clostridium pasteurianum W5 hydrogenase or the Fe(4)S(4) centers of wild-type enzyme, IspH treated with HMBPP or IPP.
Department of Chemistry, Indian Institute of Technology, Kanpur, Kanpur, 208016, India. abya@iitk.ac.in
Ameerunisha
A
Begum
Golam
G
Moula
Moumita
M
Bose
Sabyasachi
S
Sarkar
D019883:Alkyl and Aryl Transferases / Q000737:chemistry; D003013:Clostridium / Q000201:enzymology; D004578:Electron Spin Resonance Spectroscopy; D005296:Ferrous Compounds / Q000737:chemistry*; D006864:Hydrogenase / Q000737:chemistry; D007211:Indoles / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010755:Organophosphates / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000737:chemistry*
C467061:4-hydroxy-3-methyl-2-butenyl diphosphate; D005296:Ferrous Compounds; D007211:Indoles; D007506:Iron-Sulfur Proteins; D009942:Organometallic Compounds; D010755:Organophosphates; D013438:Sulfhydryl Compounds; C041272:indolepropanol phosphate; D006864:Hydrogenase; D019883:Alkyl and Aryl Transferases