细胞色素P-450模拟酶的快速混合停流时间分辨吸收谱研究Ⅰ.FeⅢ(Por.)Cl┐PhIO体系

Stopped Flow Time Resolved Studies of Cytochrome P 450 Enzyme Mimic Systems Ⅰ. Fe Ⅲ (Por.)Cl PhIO Systems

采用快速混合停流技术，在实际反应条件下，考察了不同铁卟啉配合物ＦｅⅢ（Ｐｏｒ．）Ｃｌ（Ｐｏｒ．＝ＴＰＰ、ＴＭＯＰＰ和ＴＦＰＰ）与单氧给体ＰｈＩＯ构建的模拟酶体系中催化活性物种的生成及催化烯烃环氧化过程．在氧给体ＰｈＩＯ作用下，ＦｅⅢ（Ｐｏｒ．）Ｃｌ均生成了四价铁氧卟啉配合物，但ＦｅⅢ（ＴＰＰ）Ｃｌ和ＦｅⅢ（ＴＭＯＰＰ）Ｃｌ存在严重的氧化分解，而ＦｅⅢ（ＴＦＰＰ）Ｃｌ则基本未发生氧化分解，且在底物ＤＰＢＤ存在下它的催化活性较高．

The reaction of different iron porphrin complexes Fe Ⅲ (TPP)Cl [tetraphenylporphinatoiron(III) chloride], Fe Ⅲ (TMOPP)Cl [ tetrakis(4 methoxy phenyl)porphinatoiron(III) chloride ] and Fe Ⅲ (TFPP)Cl [ tetrakis(pentafluoro phenyl)porphinatoiron(III) chloride ] with single oxygen atom donor iodosobenzene (PhIO) under ambient conditions has been investigated by rapid mixing stopped flow spectrophotometry. It is shown that the same oxoiron(IV) porphyrin complexes intermediates are produced, and the Fe Ⅲ (TFPP)Cl model system that incorporates electronic and steric protection of the oxidation vulnerable meso position is more stable. Preliminary substitution effect data reveal the following trends for Fe Ⅲ (Pro.)Cl decomposition: Fe Ⅲ (TMOPP)Cl>Fe Ⅲ(TPP)Cl(Fe Ⅲ>TFPP)Cl. Epoxidization reactivity of 1,4 diphenylbutadiene by Fe Ⅲ(TFPP)Cl PhIO model system is highest.