| Summary: | 碩士 === 國立臺灣師範大學 === 化學系在職進修碩士班 === 97 === Abstract
In order to mimic the active site of quercetin 2,3-dioxygenase, which catalyzes the oxidative cleavage of flavonals, a bis(benzimidazolyl) polydentate ligand, bis(1-methylbenzimidazole-2-ylmethyl)-N-p-toluene- sulfonylamine (L), was prepared to synthesize complexes of Ni(II), Cu(II), Zn(II), and Mn(II), which were fully characterized by elemental analysis, UV/vis, ESI-MS, IR spectroscopies, and X-ray crystallography. The synthesized complexes was employed to examine the reactions of 3-hydroxyflavone and dioxygen in the presence of 1 mol%, 5 mol%, and 10 mol% of mental complexes, and the reactions were monitored by UV/vis spectroscopy. Two complexes, [LNi(DMF)3](ClO4)2 (3) and LNiCl2 (4), were found to possess the catalytic ability towards the oxidative cleavage reaction of 3-hydroxyflavone. With 10 mol% of complexes 3 or 4, the catalytic rate of the reactions were 6.0 or 5.8 times faster than that of the control experiment. This is the first example in the literature. However, complexes, [LCu-(DMF)3](ClO4)2 (1), LCuCl2•0.5- CH3OH (2), [LMn(H2O)(DMF)-(CH3CN)](ClO4)2 (6), and [LZn(H2O)(CH3CN)](ClO4)2 (5), can not catalyze the above reaction. It is possible that L of 1, 2, and 6 was dissociated from the complexes in the reaction with 3-hydroxyflavone, or the substrate, 3-hydroxyflavone, was only coordinated to 5 and not to be catalyzed.
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