Models for the molybdenum hydroxylases: synthesis, characterization and reactivity of cis-oxosulfido-Mo(VI) complexes.
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.
Doonan
Christian J
CJ
School of Chemistry, University of Melbourne, Victoria 3010, Australia.
Nielsen
David J
DJ
Smith
Paul D
PD
White
Jonathan M
JM
George
Graham N
GN
Young
Charles G
CG
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
D009942:Organometallic Compounds; D013440:Sulfides; D008982:Molybdenum; D006899:Mixed Function Oxygenases