title: Monooxomolybdenum(VI) complexes possessing olefinic dithiolene ligands: probing Mo-S covalency contributions to electron transfer in dimethyl sulfoxide reductase family molybdoenzymes.
abstract: A monooxomolybdenum(VI) model complex for the oxidized active site in the DMSOR family of molybdoenzymes has been synthesized and structurally characterized. The compound was obtained from the desoxomolybdenum(IV) derivative by clean oxygen-atom transfer from an amine N-oxide in a manner similar to that observed in the enzyme. A combination of electronic absorption and resonance Raman spectroscopies, coupled with the results of bonding and excited-state calculations, has been used to provide strong support for a highly covalent Mo(d(xy))-S(dithiolene) pi*-bonding interaction in the molybdenum(VI) complex. It is proposed that the resulting Mo-S covalency facilitates electron-transfer regeneration of the catalytically competent DMSOR Mo(IV) active site.
authors.affiliation: Department of Material and Life Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. sugimoto@mls.eng.osaka-u.ac.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Sugimoto
authors.forename: Susumu
authors.initials: S
authors.lastname: Tatemoto
authors.forename: Koichiro
authors.initials: K
authors.lastname: Suyama
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Miyake
authors.forename: Regina P
authors.initials: RP
authors.lastname: Mtei
authors.forename: Shinobu
authors.initials: S
authors.lastname: Itoh
authors.forename: Martin L
authors.initials: ML
authors.lastname: Kirk
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004583:Electrons; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000378:metabolism*; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D008982:Molybdenum / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D000475:Alkenes; D007506:Iron-Sulfur Proteins; D008024:Ligands; D009942:Organometallic Compounds; D013438:Sulfhydryl Compounds; D008982:Molybdenum; D010088:Oxidoreductases; C045664:dimethyl sulfoxide reductase