An analogue system displaying all the important processes of the catalytic cycles involving monooxomolybdenum(VI) and desoxomolybdenum(IV) centers.
The mononuclear monooxomolybdenum(VI) complex hydrotris(3,5-dimethyl-1-pyrazolyl)borato(bis-4-ethoxyphenolato)oxomoylybdenum(VI) cation, [LMoVIO(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, LMoVO(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 [LMoVIO(p-OC6H4-OC2H5)2]+ react with tertiary phosphines (PR3) to generate phosphineoxide-bound adducts, [LMoIV(OPR3)(p-OC6H4-OC2H5)2]+, which subsequently generate the cationic desoxo species, [LMoIV(p-OC6H4-OC2H5)2]+ and OPR3. In the presence of water and an oxidizing agent the desoxo species generates the monooxomolybdenum(V), LMoVO(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.
Nemykin
Victor N
VN
The Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282, USA.
Davie
Scott R
SR
Mondal
Sujit
S
Rubie
Nick
N
Kirk
Martin L
ML
Somogyi
Arpad
A
Basu
Partha
P
D001665:Binding Sites; D002384:Catalysis; D008982:Molybdenum / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010084:Oxidation-Reduction; D021241:Spectrometry, Mass, Electrospray Ionization
D009942:Organometallic Compounds; D008982:Molybdenum