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        검색결과 3

        1.
        2002.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The catalytic activities of several metalloporphyrin, wherein the porphyrins are TPP(5,lO,l5,20-Tetraphenyl-21H,23H-porphyrin) and (p-X)TPP (X =CH3O, CH3, F, Cl), are reported for the oxidation of styrene and it's derivatives. The electronic effects of substrates and porphyrins on the catalytic activity of metalloporphyrin containing the transition metal ion such as Mn(III) was discussed. Investigating the correlation between the Michaelis-Menten's rate parameters and the substituent constants, we are going to analyze the influences on the changes of catalytic activity or rate determining step during the processes of the formation and the dissociation of the M-oxo-olefin.
        4,000원
        2.
        1995.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Benzoyl styrene derivatives were synthesized by Claisen-Schmidt condensation. It was measured that nucleophilic addition of thiourea for benzoyl styrene made use of ultraviolet spectrophotometery at a wide pH 1.0~13.0 range in 5% dioxane-H2O at 40℃. On the basis of general base catalysis, substitutent effect, and confirmation of addtion reaction product, the nucleophilic addtion kinetics of thiourea for benzoylstyrene derivatives were measured by pH change. It maybe concluded that a part was unrelated to pH and another part was in proportion to concentration of hydroxide ion : Above pH 10.0. It was in propotion to concentration of hydroxide ion, a part having no concern with pH was added to the neutral thiourea molecule. From the results of measurement the reaction rate and there findings, nucleophilic addition of thiourea to benzoylstyrene derivative was proposed a fitting mechanism.
        4,000원
        3.
        1995.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Hydrolysis kinetics of Benzoyl Styrene Derivatives[I]~[IV] was investigated by ultraviolet spectrophotometery in 5% dioxane-H2O at 40℃. The structure of these compounds were ascertained by means of ultraviolet, melting point, IR and NMR spectra. The rate equations which were applied over a wide pH range (pH 1.0~13.0) were obtained. The substituent effects on Benzoyl styrene derivatives[I]~[IV] were studied, and the hydrolysis were facilitated by electron attracting groups. On the basis of the rate equation and substitutent effect and final product, the plausible hydrolysis reaction mechanism was proposed: At pH 1.0~pH 9.0, not relevant to the hydrogenl ion concentration, neutral H2O molecule competitively attacked on the double bond. By contrary. Above pH 9.0, It was proportional to concentration of hydroxidel ion.
        4,000원