title: Models for the molybdenum hydroxylases: synthesis, characterization and reactivity of cis-oxosulfido-Mo(VI) complexes.
abstract: Atom transfer reactions have been employed to convert Tp(i)(Pr)MoO(2)(OAr) into monomeric cis-oxosulfido-Mo(VI) and dimeric mu-disulfido-Mo(V) species, [Tp(i)(Pr)MoOS(OAr)](n)() (Tp(i)(Pr) = hydrotris(3-isopropylpyrazol-1-yl)borate; OAr = phenolate or naphtholate derivative; n = 1 and 2, respectively). Dark red, monomeric Tp(i)(Pr)MoOS(OAr) complexes contain distorted octahedral cis-oxosulfido-Mo(VI) centers, with d(Mo=O) = 1.692(5) A, d(Mo=S) = 2.132(2) A, and angle(O=Mo=S) = 103.68(16) degrees for the 2-sec-butylphenolate derivative. Dark red-purple, dimeric [Tp(i)(Pr)MoOS(OAr)](2) complexes undergo S-S bond cleavage forming monomeric oxosulfido-Mo(VI) species in solution. In the solid state, the 3,5-di-tert-butylphenolate derivative exhibits a centrosymmetric structure, with distorted octahedral anti oxo-Mo(V) centers bridged by a disulfido-kappaS,kappaS' ligand. Hydrolysis of the oxosulfido-Mo(VI) complexes results in the formation of [Tp(i)(Pr)MoO](2)(mu-S(2))(mu-O). In anaerobic solutions, certain oxosulfido-Mo(VI) complexes convert to molybdenyl complexes bearing bidentate 2-mercaptophenolate or related naphtholate ligands formed via intramolecular attack of the sulfido ligand on a coligand C-H group. The oxosulfido-Mo(VI) complexes serve as precursors to biologically relevant Mo(V) and heterobimetallic MoO(mu-S)Cu species and undergo a range of biomimetic reactions.
authors.affiliation: School of Chemistry, University of Melbourne, Victoria 3010, Australia.
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Doonan
authors.forename: David J
authors.initials: DJ
authors.lastname: Nielsen
authors.forename: Paul D
authors.initials: PD
authors.lastname: Smith
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: White
authors.forename: Graham N
authors.initials: GN
authors.lastname: George
authors.forename: Charles G
authors.initials: CG
authors.lastname: Young
mesh_terms: D006899:Mixed Function Oxygenases / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008982:Molybdenum / Q000737:chemistry* / Q000378:metabolism; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D013440:Sulfides / Q000737:chemistry / Q000378:metabolism
chemical_list: D009942:Organometallic Compounds; D013440:Sulfides; D008982:Molybdenum; D006899:Mixed Function Oxygenases