Abstract:

The reactions 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 m chloroperoxybenzoic acid ( m CPBA) 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 incorporated electronic and steric protection of the oxidation vulnerable meso position is more stable. Preliminary substituent 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(TPP)Cl or Fe Ⅲ(TMOPP)Cl with m CPBA is enhanced, although the catalytic reactivity of Fe Ⅲ(TFPP)Cl m CPBA model system in CH 2Cl 2 is lower, but is faster in the presence of methanol.

Key words: Irom porphrin complexes, m-chloroperoxybenzoic acid, Diphenylbutadiene, Epoxidization, Stopped-flow