Systematic Investigation of Relationship between Strength of NH···S Hydrogen Bond and Reactivity of Molybdoenzyme Models

摘要

A series of monooxomolybdenum(IV) andndioxomolybdenum(VI) complexes containing two intramolecularnNH···S hydrogen bonds were synthesized and characterizednby 1H NMR, UV−visible, IR, and Raman spectroscopies,nand electrochemical measurements. Elimination of thensteric effects enabled the accurate and quantitative evaluation ofnNH···S hydrogen bonds. Strong correlations among thenstrength of the hydrogen bond, the strength of the MoVIOnbond, and the redox potential were clearly shown. Thenhydrogen bonds stabilize the intermediate in the reaction between the monooxomolybdenum(IV) and Me3NO, resulting innacceleration of the reaction or retardation of trans−cis rearrangement. The proposed intermediate and the reaction mechanism,ndiscussed on the basis of theoretical calculations, provided a unified explanation of the reaction.