Department of Molecular Chemistry and Biochemistry, Doshisha University , Kyotanabe, Kyoto 610-0321, Japan.
Inorg Chem. 2014 Jan 6;53(1):543-51. doi: 10.1021/ic4026393. Epub 2013 Dec 12.
A 1:1 supramolecular complex (met-hemoCD) of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinatoiron(III) (Fe(III)TPPS) with a per-O-methylated β-cyclodextrin dimer having a -SCH2PyCH2S- (Py = pyridin-3,5-diyl) linker (Py3CD) reacted rapidly with hydrogen peroxide or cumene hydroperoxide in an aqueous solution forming two types of hydroperoxo or alkylperoxo intermediates, ROO-Fe(III)(OH(-))PCD and ROO-Fe(III)(Py)PCD, which underwent rapid homolysis to the corresponding ferryloxo species, namely, O═Fe(IV)(OH(-))PCD and O═Fe(IV)(Py)PCD, respectively. For the O═Fe(IV)(OH(-))PCD species, the iron-oxo oxygen facing the linker gradually transferred to the nearby sulfide bond on the linker, forming the sulfoxidized Py3CD (Py3CD-O)/Fe(II)TPPS complex, which then bound dioxygen in air forming an oxy-ferrous complex, O2-Fe(II)TPPS/Py3CD-O. In contrast, the O═Fe(IV)(Py)PCD species, in which the iron-oxo oxygen was located on the opposite side of the sulfide bond on the linker across the porphyrin ring, was reduced to the resting state (met-hemoCD) by the surroundings without any oxidation of the Py3CD linker.
A 1:1 超分子复合物（met-hemoCD）由 5,10,15,20-四(4-磺酸钠苯基)卟啉铁(III)（Fe(III)TPPS）与具有 -SCH2PyCH2S-（Py=吡啶-3,5-二基）连接体的全-O-甲基化 β-环糊精二聚体（Py3CD）组成，在水溶液中与过氧化氢或枯烯氢过氧化物快速反应，形成两种类型的过氧氢或过氧烷基中间体，ROO-Fe(III)(OH(-))PCD 和 ROO-Fe(III)(Py)PCD，它们迅速均裂生成相应的 Ferryloxo 物种，即 O═Fe(IV)(OH(-))PCD 和 O═Fe(IV)(Py)PCD。对于 O═Fe(IV)(OH(-))PCD 物种，铁-氧面对连接体的氧逐渐转移到连接体上的附近的硫键上，形成磺氧化的 Py3CD（Py3CD-O）/Fe(II)TPPS 配合物，然后在空气中结合氧气形成氧合亚铁配合物，O2-Fe(II)TPPS/Py3CD-O。相比之下，O═Fe(IV)(Py)PCD 物种中，铁-氧位于连接体上硫键的对面，穿过卟啉环，由于周围环境的原因，没有任何氧化的 Py3CD 连接体而被还原为静止状态（met-hemoCD）。
