A5015605803- Metal-Catalyzed Oxygenation Mechanisms
- Porphyrin and Phthalocyanine Chemistry
- Metal complexes synthesis and properties
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Oxidative Organic Chemistry Reactions
- Magnetism in coordination complexes
- Photosynthetic Processes and Mechanisms
- Lanthanide and Transition Metal Complexes
- Metalloenzymes and iron-sulfur proteins
- CO2 Reduction Techniques and Catalysts
- Heme Oxygenase-1 and Carbon Monoxide
- Radioactive element chemistry and processing
- Hemoglobin structure and function
- Vanadium and Halogenation Chemistry
- Synthesis and Catalytic Reactions
- Crystallography and molecular interactions
- Porphyrin Metabolism and Disorders
- Ferrocene Chemistry and Applications
- Electron Spin Resonance Studies
- Microbial metabolism and enzyme function
- DNA and Nucleic Acid Chemistry
- Radiomics and Machine Learning in Medical Imaging
- Electrocatalysts for Energy Conversion
- Free Radicals and Antioxidants
Ewha Womans University
2016-2025
Seoul National University
2024
AstraZeneca (South Korea)
2023
Ewha Womans University Medical Center
2004-2020
Seoul Institute
2017-2020
University of Ulsan
2017
Asan Medical Center
2012-2017
Ulsan College
2017
Korea Advanced Nano Fab Center
2011
Institute of Organic Chemistry
2010
A new fluorescent sensor based on rhodamine B for Pb2+ was synthesized. The showed an extreme selectivity over other metal ions examined in acetonitrile. Upon the addition of Pb2+, overall emission change 100-fold observed, and calculated to be 200 times that Zn2+. signal transduction occurs via reversible CHEF (chelation-enhanced fluorescence) with this inherent quenching ion.
Abstract Terminal cobalt(IV)–oxo (Co IV –O) species have been implicated as key intermediates in various cobalt-mediated oxidation reactions. Herein we report the photocatalytic generation of a mononuclear non-haem [(13-TMC)Co (O)] 2+ ( 2 ) by irradiating [Co II (13-TMC)(CF 3 SO )] + 1 presence [Ru (bpy) ] , Na S O 8 and water an oxygen source. The intermediate was also obtained reacting with artificial oxidant (that is, iodosylbenzene) characterized spectroscopic techniques. In particular,...
The reactions of manganese(III) porphyrin complexes with terminal oxidants, such as m-chloroperbenzoic acid, iodosylarenes, and H(2)O(2), produced high-valent manganese(V)-oxo porphyrins in the presence base organic solvents at room temperature. have been characterized various spectroscopic techniques, including UV-vis, EPR, 1H 19F NMR, resonance Raman, X-ray absorption spectroscopy. combined results indicate that are diamagnetic low-spin (S = 0) species a longer, weaker Mn-O bond than...
A mononuclear non-heme manganese(IV)-oxo complex has been synthesized and characterized using various spectroscopic methods. The Mn(IV)-oxo shows high reactivity in oxidation reactions, such as C-H bond activation, oxidations of olefins, alcohols, sulfides, aromatic compounds, N-dealkylation. In the can activate bonds strong those cyclohexane. It is proposed that activation by does not occur via an oxygen-rebound mechanism. electrophilic character demonstrated a large negative ρ value -4.4...
Redox-inactive metal ions play pivotal roles in regulating the reactivities of high-valent metal-oxo species a variety enzymatic and chemical reactions. A mononuclear non-heme Mn(IV)-oxo complex bearing pentadentate N5 ligand has been synthesized used synthesis binding scandium ions. The complexes were characterized with various spectroscopic methods. are markedly influenced by Sc(3+) oxidation reactions, such as ~2200-fold increase rate thioanisole (i.e., oxygen atom transfer) but ~180-fold...
A series of complexes [Fe(IV)(O)(TMC)(X)](+) (where X = OH(-), CF3CO2(-), N3(-), NCS(-), NCO(-), and CN(-)) were obtained by treatment the well-characterized nonheme oxoiron(IV) complex [Fe(IV)(O)(TMC)(NCMe)](2+) (TMC tetramethylcyclam) with appropriate NR4X salts. Because topology TMC macrocycle, represents an extensive collection S 1 that only differ respect to ligand trans oxo unit. Electronic absorption, Fe K-edge X-ray resonance Raman, Mossbauer data collected for these conclusively...
A highly reactive mononuclear nonheme iron(IV)-oxo complex with a low-spin (S = 1) triplet ground state in both C–H bond activation and oxo transfer reactions is reported; this more than an porphyrin π-cation radical (i.e., model of cytochrome P450 compound I) the most species kinetic studies among complexes reported so far. DFT calculations support experimental results extremely low barriers cyclohexane 1,4-cyclohexadiene. The reveal that S 1 set up to easily lead 2 high-spin species.
Triflic acid (HOTf)-bound nonheme Mn(IV)-oxo complexes, [(L)MnIV(O)]2+-(HOTf)2 (L = N4Py and Bn-TPEN; N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) Bn-TPEN N-benzyl-N,N',N'-tris(2-pyridylmethyl)ethane-1,2-diamine), were synthesized by adding HOTf to the solutions of [(L)MnIV(O)]2+ complexes characterized various spectroscopies. The one-electron reduction potentials MnIV(O) exhibited a significant positive shift upon binding HOTf. driving force dependence electron transfer (ET) from...
Mononuclear nonheme manganese(IV)-oxo complexes binding calcium ion and other redox-inactive metal ions, [(dpaq)MnIV(O)]+-M n+ (1-Mn+, M = Ca2+, Mg2+, Zn2+, Lu3+, Y3+, Al3+, Sc3+) (dpaq 2-[bis(pyridin-2-ylmethyl)]amino- N-quinolin-8-yl-acetamidate), were synthesized by reacting a hydroxomanganese(III) complex, [(dpaq)MnIII(OH)]+, with iodosylbenzene (PhIO) in the presence of ions (M n+). The Mn(IV)-oxo characterized using various spectroscopic techniques. In reactivity studies, we observed...
Iron-mediated oxidation: High-valent iron(IV)–oxo complexes of heme and nonheme ligands are generated in situ used mechanistic studies alcohol oxidation (see scheme). It is proposed that the alcohols occurs by an α-CH hydrogen atom abstraction followed electron transfer. Porp=porphyrin. Supporting information for this article available on WWW under http://www.wiley-vch.de/contents/jc_2002/2005/z500623_s.pdf or from author. Please note: The publisher not responsible content functionality any...
Axial ligand substitution of a mononuclear nonheme oxoiron(IV) complex, [FeIV(O)(TMC)(NCCH3)]2+ (1) (TMC = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane), leads to the formation new FeIV=O species with relatively intense electronic absorption features in near-UV region. The presence these allowed us make first observation Fe=O vibrations S 1 complexes by resonance Raman spectroscopy. We have also demonstrated that reactivity intermediates is markedly influenced axial ligands.
We have used dioxygen, not artificial oxidants such as peracids, iodosylarenes, and hydroperoxides, in the generation of a mononuclear nonheme oxoiron(IV) complex, [Fe(IV)(TMC)(O)]2+ (TMC = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane), from its corresponding Fe(II) [Fe(TMC)(CF3SO3)2]. The formation species by activating dioxygen was markedly dependent on iron(II) complexes solvents, this observation interpreted with electronic effect activation to form species. A catalytic aerobic...
On the side: The crystal structure of a peroxido MnIII complex bearing non-heme ligand shows that peroxide is bound to manganese ion symmetrically in side-on η2 fashion. capable deformylating aldehydes by nucleophilic reaction but not oxygenating substrates an electrophilic reaction. tmc=1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane. Supporting information for this article available on WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z603414_s.pdf or from author. Please note:...
An "end-on" Ni2+-superoxo adduct has been prepared via two independent synthetic routes and its structure ascertained by spectroscopic computational methods. The new type in nickel coordination chemistry is supported resonance Raman EPR features, the former displaying a high frequency nu (O-O) mode (1131 cm-1) consistent with significant superoxo character. oxidizes PPh3 to OPPh3 quantitative yield.
An advanced intermediate: A nonheme iron(IV) oxo complex [Fe(IV)(O)(bqen)(L)](n+) (bqen = N,N'-dimethyl-N,N'-bis(8-quinolyl)ethane-1,2-diamine, L CH(3)CN or CF(3)SO(3)(-)) activates the C-H bonds of alkanes and alcohols by a hydrogen-atom abstraction mechanism. The catalytic oxidation these species is proposed to occur through iron(V) species, with high reactivity in reactions (see picture).
The source of the problem: Experiments with isotopically labeled water can be used to unambiguously assign oxygen in a nonheme manganese(IV) oxo complex. complex, which was generated using as an and cerium(IV) oxidant (see picture), shows reactivities activation CH bonds alkyl-functionalized aromatic molecules oxidation substrates (sub) benzyl alcohol. Detailed facts importance specialist readers are published "Supporting Information". Such documents peer-reviewed, but not copy-edited or...
Mononuclear nonheme high-spin iron(III)-acylperoxo complexes bearing an N-methylated cyclam ligand were synthesized, spectroscopically characterized, and investigated in olefin epoxidation alkane hydroxylation reactions. In the of olefins, epoxides yielded as major products with high stereo-, chemo-, enantioselectivities; cis- trans-stilbenes oxidized to trans-stilbene oxides, respectively. cyclohexene, cyclohexene oxide was formed product a kinetic isotope effect (KIE) value 1.0, indicating...
Activation of dioxygen (O
We report that Mn(IV)-oxo porphyrin complexes, MnIV(O)(TMP) (1) and MnIV(O)(TDCPP) (2), are capable of activating the C–H bonds hydrocarbons, including unactivated alkanes such as cyclohexane, via an oxygen non-rebound mechanism. Interestingly, 1 with electron-rich is more reactive than 2 electron-deficient at a high temperature (e.g., 0 °C). However, low −40 °C), reactivity reversed, showing 1. To best our knowledge, present study reports first example highly porphyrins their...
Rates of exchange: Evidence that nonheme oxoiron(IV) complexes exchange their oxygen atoms with H218O was obtained for the first time, by monitoring electrospray ionization mass spectral changes species. The oxygen-atom depended markedly on amounts present and reaction temperatures but not presence trans axial ligand (see scheme).
Nonheme and heme iron monooxygenases participate in oxidative N-dealkylation reactions nature, high-valent oxoiron(IV) species have been invoked as active oxidants that effect the oxygenation of organic substrates. The present study describes first example N,N-dialkylamines by synthetic nonheme complexes reactivity comparisons complexes. Detailed mechanistic studies were performed with various N,N-dialkylaniline substrates such para-substituted N,N-dimethylanilines,...
A mononuclear nonheme oxoiron(IV) complex bearing a pentadentate N5 ligand was prepared in aqueous solution; the pH dependence of its stability and reactivities reported along with mechanistic details sulfide oxidation by species.
A non-heme manganese(II) complex shows a high catalytic activity in the epoxidation of olefins by iodosyl benzene and oxidation olefins, alcohols alkanes peracetic acid; mechanism involving metal-based oxidants is proposed for reactions.
A mononuclear nonheme ferric-peroxo complex bearing a macrocyclic tetradentate N4 ligand, [(TMC)FeIII–O2]+, was prepared and used in mechanistic studies of aldehyde deformylation; catalytic deformylation by iron(II) complex, [FeII(TMC)]2+, molecular oxygen is reported as well.