An Analogue System Displaying All the Important Processes of the Catalytic Cycles Involving Monooxomolybdenum(VI) and Desoxomolybdenum(IV) Centers

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• 作者：Victor N. Nemykin ; Scott R. Davie ; Sujit Mondal ; Nick Rubie ; Martin L. Kirk ; Arpad Somogyi ; and Partha Basu
• 刊名：Journal of the American Chemical Society
• 出版年：2002
• 出版时间：February 6, 2002
• 年：2002
• 卷：124
• 期：5
• 页码：756 - 757
• 全文大小：37K
• 年卷期：v.124,no.5(February 6, 2002)
• ISSN：1520-5126

文摘

The mononuclear monooxomolybdenum(VI) complex hydrotris(3,5-dimethyl-1-pyrazolyl)borato(bis-4-ethoxyphenolato)oxomoylybdenum(VI) cation, [LMo^VIO(p-OC₆H₄-OC₂H₅)₂]⁺, where L^- = hydrotris(3,5-dimethyl-1-pyrazolyl)borate, has been synthesized by chemical and electrochemical oxidation from the corresponding neutral oxomolybdenum(V) species, LMo^VO(p-OC₆H₄-OC₂H₅)₂. The molybdenum(VI) species has been characterized by NMR, IR, and resonance Raman spectroscopies, mass spectrometry, and electronic spectroscopy. Acetonitrile solutions of cationic [LMo^VIO(p-OC₆H₄-OC₂H₅)₂]⁺ react with tertiary phosphines (PR₃) to generate phosphineoxide-bound adducts, [LMo^IV(OPR₃)(p-OC₆H₄-OC₂H₅)₂]⁺, which subsequently generate the cationic desoxo species, [LMo^IV(p-OC₆H₄-OC₂H₅)₂]⁺ and OPR₃. In the presence of water and an oxidizing agent the desoxo species generates the monooxomolybdenum(V), LMo^VO(p-OC₆H₄-OC₂H₅)₂, and completes the catalytic cycle. The oxygen atom transfer reaction has been probed by isotope-labeling experiments, vibrational spectroscopies, and mass spectrometry. This study describes an analogue complex that can exhibit all important processes of the catalytic cycle involving monooxomolybdenum(VI) and desoxomolybdenum(IV) centers.