A stabilized μ-η2:η2 peroxodicopper(II) complex with a secondary diamine ligand and its tyrosinase-like reactivity
A stabilized μ-η2:η2 peroxodicopper(II) complex with a secondary diamine ligand and its tyrosinase-like reactivity
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DOI：
10.1021/ja026905p
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发表时间：
2002-08-14
影响因子：
15
通讯作者：
Stack, TDP
中科院分区：
文献类型：
--
作者：
Mirica, LM;Vance, M;Stack, TDP
在生物和工业应用中，铜(I)络合物对O2的活化是一个普遍存在的过程。在双核铜酶酪氨酸酶中，μ-η2：η2-Peroxodicoper(II)物种被普遍认为是活性氧化剂。报道了一种稳定的μ-η2：η2-过氧二铜(II)络合物在−80°C下的表征和反应活性。该络合物的光谱性质(UV-−-Vis，共振拉曼光谱)强烈依赖于所用的反阴离子，而不是溶剂，这表明反阴离子与铜−O2核发生了密切的相互作用。解决方案EXAFS数据也支持这种交互作用。这种新的络合物通过将酚类化合物转化为儿茶酚而表现出羟基化反应活性，被证明是酪氨酸酶的功能模型。对这种铜/氧物种的额外兴趣来自于使用铜(I)−DBED作为聚合催化剂，以O2为末端氧化剂将苯酚聚合为聚苯醚(PPO)。
The activation of dioxygen (O2) by Cu(I) complexes is an ubiquitous process in biology and industrial applications. In tyrosinase, a binuclear copper enzyme, aμ-η2:η2-peroxodicopper(II) species is generally accepted to be the active oxidant. Reported here is the characterization and reactivity of a stableμ-η2:η2-peroxodicopper(II) complex at −80 °C using a secondary diamine ligand,N,N‘-di-tert-butyl-ethylenediamine (DBED). The spectroscopic characteristics of this complex (UV−vis, resonance Raman) prove to be strongly dependent on the counteranion employed and not on the solvent, suggesting an intimate interaction of the counteranions with the Cu−O2cores. This interaction is also supported by solution EXAFS data. This new complex exhibits hydroxylation reactivity by converting phenolates to catechols, proving to be a functional model of tyrosinase. Additional interest in this Cu/O2species results from the use of Cu(I)−DBED as a polymerization catalyst of phenols to polyphenylene oxide (PPO) with O2as the terminal oxidant.