双核铜酶模型的合成及对安息香的催化氧化

Synthesis of Binuclear Copper Enzyme Models and Their Catalytic Behaviour in Oxidation of Benzoin

双核铜酶属氧化还原酶,其活性中心有两个铜原子,每个铜与三个组氨酸中的咪唑基配位,Cu-Cu间距为0.34～0.37nm,氧分子以顺μ-1,2过氧基形式络合。近年,双核铜酶的化学模拟进展十分迅速,在氧的键合、活化,基质的氧化。

Four new binuclear copper enzyme models (6～9) are efficiently synthesized andstructurally confirmed. σ-chloro phenol is treated with paraformaldehyde and imidazoleto give the bis-imidazolylmethyl derivative 2. Treatment of 2 with χ, ω-dibromoalkanesgives the corresponding coupling derivatives 3～5. Three models 6～8 are obtained from the reac-tion of [Cu(CH_3CN)_4] CLO_4 with 3～5. Another model (9) was Likewise synthesized under other-wise identical condition except employing p-chloro phenol in place of the ο-counterpart. Oxidation reactions of benzoin to benzil catalyzed by 6～9 with oxygen have also been inves-tigated. The catalytic ability in the following order: 7>4+[Cu(CH_3CN)_4] ClO_4>[Cu(CH_3(CN)_4]ClO_4>2+[Cu(CH_3CN)_4] ClO_4 is observed. In the presence of 7, the oxidation reaction followsMichaelis-Menten Saturation behaviour and the kinetic parameters are obtained.