생체 모방 분자 연구실

Transition metal−iodosylarene complexes have been proposed to be key intermediates in the catalytic cycles of metal catalysts with iodosylarene. We report the first X-ray crystal structure and spectroscopic characterization of a mononuclear nonheme manganese- (III)−iodosylarene complex with a tetradentate macrocyclic ligand, [MnIII(TBDAP)(OIPh)(OH)]2+. The manganese(III)−iodosylarene complex is capable of conducting various oxidation reactions with organic substrates, such as C−H bond activation, sulfoxidation and epoxidation. Kinetic studies including isotope labeling experiments and Hammett correlation demonstrate the electrophilic character on the Mn−iodosylarene adduct. This novel intermediate would be prominently valuable for expanding the chemistry of transition metal catalysts. Naphthalene oxidation with metal–oxygen intermediates is a difficult reaction in environmental and biological chemistry. We report that a MnIV bis(hydroxo) complex, which was fully characterized by various physicochemical methods, such as ESI‐MS, UV/Vis, and EPR analysis, X‐ray diffraction, and XAS, can be employed for the oxidation of naphthalene in the presence of acid to afford 1,4‐naphthoquinone. Redox titration of the MnIV bis(hydroxo) complex gave a one‐electron reduction potential of 1.09 V, which is the most positive potential for all reported nonheme MnIV bis(hydroxo) species as well as MnIV oxo analogues. Kinetic studies, including kinetic isotope effect analysis, suggest that the naphthalene oxidation occurs through a rate‐determining electron transfer process. Nitric oxide (NO) is a crucial signaling molecule involved in various pharmacological and pathological processes, including vasodilation, immune response, and neuroplasticity. However, delivering a precise amount of NO to