Jieun Jung 교수

A highly efficient tetradentate PNNP-type Ir photocatalyst, Mes-IrPCY2, was developed for the reduction of carbon dioxide. The photocatalyst furnished formic acid (HCO₂H) with 87% selectivity together with carbon monoxide to achieve a turnover number of 2560, which is the highest among CO₂ reduction photocatalysts without an additional photosensitizer. Mes-IrPCY2 exhibited outstanding photocatalytic CO₂ reduction activity in the presence of the sacrificial electr

Theoretical investigations using density functional theory (DFT) have been carried out to understand the interaction between mercury (Hg) and hematite (α-Fe2O3), both of which are released during the coal combustion processes. A clean α-Fe2O3(11̅02) surface was chosen as a representative hematite model in this study based upon a previous ab initio thermodynamics study showing the high stability of this surface in the temperature range of typical flue gases. In order to determine the effect of ch

Hydroxylation of mesitylene by a nonheme manganese(IV)-oxo complex, [(N4Py)Mn(IV) (O)](2+) (1), proceeds via one-step hydrogen-atom transfer (HAT) with a large deuterium kinetic isotope effect (KIE) of 3.2(3) at 293 K. In contrast, the same reaction with a triflic acid-bound manganese(IV)-oxo complex, [(N4Py)Mn(IV) (O)](2+) -(HOTf)2 (2), proceeds via electron transfer (ET) with no KIE at 293 K. Interestingly, when the reaction temperature is lowered to less than 263 K in the reaction of 2, howev

Visible light photoirradiation of an oxygen-saturated benzonitrile solution of a manganese(III) corrolazine complex [(TBP8Cz)Mn(III)] (1): [TBP8Cz = octakis(p-tert-butylphenyl)corrolazinato(3-)] in the presence of toluene derivatives resulted in formation of the manganese(V)-oxo complex [(TBP8Cz)Mn(V)(O)]. The photochemical oxidation of (TBP8Cz)Mn(III) with O2 and hexamethylbenzene (HMB) led to the isosbestic conversion of 1 to (TBP8Cz)Mn(V)(O), accompanied by the selective oxidation of HMB to p

Photocatalytic oxygenation of 10-methyl-9,10-dihydroacridine (AcrH2) by dioxygen (O2) with a manganese porphyrin [(P)Mn(III): 5,10,15,20-tetrakis-(2,4,6-trimethylphenyl)porphinatomanganese(III) hydroxide [(TMP)Mn(III)(OH)] (1) or 5,10,15,20-tetrakis(pentafluorophenyl)porphyrinatomanganese(III) acetate [(TPFPP)Mn(III)(CH3COO)] (2)] occurred to yield 10-methyl-(9,10H)-acridone (Acr═O) in an oxygen-saturated benzonitrile (PhCN) solution under visible light irradiation. The photocatalytic reactivity

Electron transfer from octamethylferrocene (Me8Fc) to the manganese(V) imidocorrole complex (tpfc)Mn(V)(NAr) [tpfc = 5,10,15-tris(pentafluorophenyl)corrole; Ar = 2,6-Cl2C6H3] proceeds efficiently to give an octamethylferrocenium ion (Me8Fc(+)) and [(tpfc)Mn(IV)(NAr)](-) in acetonitrile (MeCN) at 298 K. Upon the addition of trifluoroacetic acid (TFA), further reduction of [(tpfc)Mn(IV)(NAr)](-) by Me8Fc gives (tpfc)Mn(III) and ArNH2 in deaerated MeCN. TFA also results in hydrolysis of (tpfc)Mn(V)

UV-vis spectral titrations of a manganese(III) corrolazine complex [Mn(III)(TBP8Cz)] with HOTf in benzonitrile (PhCN) indicate mono- and diprotonation of Mn(III)(TBP8Cz) to give Mn(III)(OTf)(TBP8Cz(H)) and [Mn(III)(OTf)(H2O)(TBP8Cz(H)2)][OTf] with protonation constants of 9.0 × 10(6) and 4.7 × 10(3) M(-1), respectively. The protonated sites of Mn(III)(OTf)(TBP8Cz(H)) and [Mn(III)(OTf)(H2O)(TBP8Cz(H)2)][OTf] were identified by X-ray crystal structures of the mono- and diprotonated complexes. In t

3d-transition metal complexes have been gaining much attention as promising candidates for photocatalytic carbon dioxide (CO₂) reduction systems. In contrast to the group 7-12 elements, Cr in group 6 has not yet been investigated as the catalyst of CO₂ photoreduction because of its intrinsic disadvantages. Cr has a weak reducing ability due to an insufficient number of d electrons and high Lewis acidity which may deactivate the catalyst by strong coordination with a product

We herein report that an iron (Fe) complex bearing a tetradentate PNNP ligand catalyzes photochemical carbon dioxide (CO2) reduction to produce mainly carbon monoxide (CO) together with formic acid (HCO2H) combined with a photosensitizer. The structurally bulky phosphine moieties stabilized the catalyst and improved its durability over a few days (∼72 h) to give the turnover number (TON) of 397. Operando subnanosecond laser-induced transient absorption measurements allowed us to observe the dire

Abstract A novel mononuclear ruthenium (Ru) complex bearing a PNNP-type tetradentate ligand is introduced here as a self-photosensitized catalyst for the reduction of carbon dioxide (CO2). When the pre-activation of the Ru complex by reaction with a base was carried out, an induction period of catalyst almost disappeared and the catalyst turnover numbers (TONs) over a reaction time of 144 h reached 307 and 489 for carbon monoxide (CO) and for formic acid (HCO2H), respectively. The complex has a

A series of Ir complexes has been developed as multifunctional photocatalysts for CO₂ reduction to give HCO₂H selectively. The catalytic activities and photophysical properties vary widely across the series, and the bulky group insertion resulted in the formation of HCO₂H and CO with the catalyst turnover number of >10 400.

Atomic-scale theoretical simulations proposes that Hg physisorbs to the α-Fe₂O₃(0001) surface with an adsorption energy of -0.278 eV, and the subsequent Bader charge analysis confirms that Hg is slightly oxidized. In addition, Cl introduced to the Hg-adsorbed surface strengthens the Hg stability on the α-Fe₂O₃(0001) surface, as evidenced by a shortened Hg-surface equilibrium distance. The PDOS analysis also suggests that Cl enhances the chemical bondin

Abstract Carbon dioxide (CO2) is an attractive renewable one-carbon (C1) feedstock in terms of its earth abundance, low cost, and non-toxicity. Developing new catalytic systems to realize the practical insertion of CO2 into organic molecules has been of great importance for ecological economics. In recent years, outstanding improvements have been carried out in the field of light-driven catalytic carboxylation via the activation of CO2 as the key reagent. In this short review, the recent develop

Abstract Hydroxylation of mesitylene by a nonheme manganese(IV)–oxo complex, [(N4Py)Mn IV (O)] 2+ ( 1 ), proceeds via one‐step hydrogen‐atom transfer (HAT) with a large deuterium kinetic isotope effect (KIE) of 3.2(3) at 293 K. In contrast, the same reaction with a triflic acid‐bound manganese(IV)‐oxo complex, [(N4Py)Mn IV (O)] 2+ ‐(HOTf) 2 ( 2 ), proceeds via electron transfer (ET) with no KIE at 293 K. Interestingly, when the reaction temperature is lowered to less than 263 K in the reaction o

A new PNNP-coordinated iridium complex, Mes-IrPPh2, immobilized on carbon was a superior catalyst for the CO 2 electrochemical reduction in water to give formate, allowing the solar-to-chemical conversion efficiency of 13.7%.