Interaction of nitric oxide with tetrathiolato iron(II) complexes: relevance to the reaction pathways of iron nitrosyls in sulfur-rich biological coordination environments.
The mechanism of formation of dinitrosyl iron complexes (DNICs) coordinated by cysteine residues at iron-sulfur protein sites has received little attention in the chemical literature. As a logical first step toward elucidating this mechanism and characterizing new iron-nitrosyl intermediates, we investigated the interaction of NO (g) and NO+ with iron-sulfur complexes chosen to mimic sulfur-rich iron sites in biology. The reaction of NO (g) with [Fe(StBu)4]2- cleanly affords the mononitrosyl complex, [Fe(StBu)3(NO)]- (1), a previously unknown species evoked in this chemistry. Reaction of [Fe(StBu)4]2- with NO derivatives, such as NO+, yields the corresponding dinitrosyl S-bridged Roussin red ester [Fe2(mu-StBu)2(NO)4] (2). The nitrosyl complexes 1 and 2 can chemically convert to the DNIC, [Fe(StBu)2(NO)2]- (3). The results should aid in the spectroscopic identification and elucidation of reaction pathways for the nitrosylation of iron in biologically related sulfur-rich coordination environments.
Harrop
Todd C
TC
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Song
Datong
D
Lippard
Stephen J
SJ
D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D005296:Ferrous Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D009569:Nitric Oxide / Q000737:chemistry* / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013438:Sulfhydryl Compounds / Q000737:chemistry* / Q000378:metabolism
D005296:Ferrous Compounds; D013438:Sulfhydryl Compounds; D009569:Nitric Oxide