Synthesis and Characterization of a Linear Dinitrosyl-Triiron Complex; Comparison to a Flavodiiron Nitric Oxide Reductase Intermediate

• Main Authors: Victor, Eric (Contributor), Minier, Mikael Antoine (Contributor), Lippard, Stephen J. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Chemistry (Contributor)
• Format: Article
• Language: English
• Published: Wiley Blackwell, 2015-03-30T17:07:15Z.
• Subjects: Article
• Online Access: Get fulltext

 Nitric oxide is released during the immune response by the host during bacterial infection. To counteract this response, bacteria have evolved nitric oxide reductases to convert NO to N[subscript 2]O. Some of these nitric oxide reductases contain a flavodiiron active site that has bridging carboxylates and hydroxides. Only a handful of synthetic complexes currently exist as models for the protein reactivity. Here, we report the reaction of [Fe[subscript 2](μ-OH)(μ-Ph[subscript 4]DBA)(TMEDA)[subscript 2](OTf)] (4) with NO(g) and Ph[subscript 3]CSNO to prepare the dinitrosyl-triiron complex [Fe[subscript 3](μ-OH)[subscript 2](μ-Ph[subscript 4]DBA)[subscript 2](TMEDA)[subscript 2](NO)[subscript 2]](OTf) (5). The reaction was monitored by UV/Vis and ReactIR spectroscopy, and compound 5 was characterized by X-ray crystallography, [superscript 57]Fe Mossbauer spectroscopy, Evan's method, and FTIR spectroscopy. The IR spectrum of compound 5 compares favorably to experimental spectroscopic data obtained for the proposed mononitrosylated intermediate of the protein.