Faculty Profiles - JUNG Jieun

Papers - JUNG Jieun

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Ferrocenyl PNNP Ligands-Controlled Chromium Complex-Catalyzed Photocatalytic Reduction of CO2 to Formic Acid

Wakabayashi, T; Kametani, Y; Tanahashi, E; Shiota, Y; Yoshizawa, K; Jung, J; Saito, S

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 2024.9

Photocatalytic CO2 Reduction Using an Osmium Complex as a Panchromatic Self‐Photosensitized Catalyst: Utilization of Blue, Green, and Red Light

Kenji Kamada, Jieun Jung, Chihiro Yamada, Taku Wakabayashi, Keita Sekizawa, Shunsuke Sato, Takeshi Morikawa, Shunichi Fukuzumi, Susumu Saito

Angewandte Chemie International Edition Vol. 63 ( 22 ) 2024.5

Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley

The photocatalytic reduction of carbon dioxide (CO2) represents an attractive approach for solar‐energy storage and leads to the production of renewable fuels and valuable chemicals. Although some osmium (Os) photosensitizers absorb long wave‐lengths in the visible‐light region, a self‐photosensitized, mono‐nuclear Os catalyst for red‐light‐driven CO2 reduction has not yet been exploited. Here, we discovered that the introduction of an Os metal to a PNNP‐type tetradentate ligand resulted in the absorption of light with longer‐wavelength (350–700 nm) and that can be applied to a panchromatic self‐photosensitized catalyst for CO2 reduction to give mainly carbon monoxide (CO) with a total turnover number (TON) of 625 under photoirradiation (λ ≥ 400 nm). CO2 photoreduction also proceeded under irradiation with blue (λ0 = 405 nm), green (λ0 = 525 nm), or red (λ0 = 630 nm) light to give CO with >90% selectivity. The quantum efficiency using red light was determined to be 12% for the generation of CO. A catalytic mechanism is proposed based on the detection of intermediates using various spectroscopic techniques, including transient absorption, electron paramagnetic resonance, and UV−vis spectroscopy.

DOI： 10.1002/anie.202403886

Web of Science

PubMed

Importance of steric bulkiness of iridium photocatalysts with PNNP tetradentate ligands for CO2 reduction

Kenji Kamada, Jieun Jung, Yohei Kametani, Taku Wakabayashi, Yoshihito Shiota, Kazunari Yoshizawa, Seong Hee Bae, Manami Muraki, Masayuki Naruto, Keita Sekizawa, Shunsuke Sato, Takeshi Morikawa, Susumu Saito

Chemical Communications Vol. 58 ( 66 ) page： 9218 - 9221 2022.8

A Highly Durable, Self-Photosensitized Mononuclear Ruthenium Catalyst for CO2 Reduction

Kenji Kamada, Hiroko Okuwa, Taku Wakabayashi, Keita Sekizawa, Shunsuke Sato, Takeshi Morikawa, Jieun Jung, Susumu SAITO

Synlett Vol. 33 ( 12 ) page： 1137 - 1141 2022.7

Language：English Publishing type：Research paper (scientific journal) Publisher：Georg Thieme Verlag KG

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 long lifespan as a dual photosensitizer and reduction catalyst, due to the sterically bulky and structurally robust (PNNP)Ru framework. Isotope labeling experiments under 13CO2 atmosphere indicate that CO and HCO2H were both produced from CO2.

DOI： 10.1055/a-1709-0280

Web of Science

Photocatalytic CO2 Reduction Using an Iron–Bipyridyl Complex Supported by Two Phosphines for Improving Catalyst Durability

Taku Wakabayashi, Kenji Kamada, Keita Sekizawa, Shunsuke Sato, Takeshi Morikawa, Jieun Jung, Susumu Saito

Organometallics Vol. 41 ( 14 ) page： 1865 - 1871 2022.5

Recent Advances in Light-Driven Carbon–Carbon Bond Formation via Carbon Dioxide Activation

Jieun Jung, Susumu Saito

Synthesis Vol. 53 ( 18 ) page： 3263 - 3278 2021.9

Language：English Publishing type：Research paper (scientific journal) Publisher：Georg Thieme Verlag KG

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 developments of light-promoted carboxylation utilizing CO2 to synthesize value-added chemicals using a dual visible-light photoredox/transition-metal catalyst or a photoredox catalyst are highlighted.

1 Introduction

2 Visible-Light-Driven Carboxylation Using Transition-Metal Photocatalysts

2.1 Transition-Metal-Catalyzed Carboxylation of Alkenes

2.2 Transition-Metal-Catalyzed Carboxylation of C(sp2)–X (X = Cl, Br, OTf) Bonds

2.3 Transition-Metal-Catalyzed Carboxylation of Alkynes

2.4 Transition-Metal-Catalyzed Carboxylation of Carbons Attached to Nitrogen

3 Light-Driven Carboxylation via Organo-Photocatalysis

3.1 Photocatalytic Carboxylation of Alkenes

3.2 Photocatalytic Carboxylation of C(sp3)–H Bonds

4 Conclusion

DOI： 10.1055/a-1577-5947

Web of Science

Photocatalytic hydrogen evolution using a Ru(ii)-bound heteroaromatic ligand as a reactive site

Takuya Sawaki, Tomoya Ishizuka, Nanase Namura, Dachao Hong, Mayuko Miyanishi, Yoshihito Shiota, Hiroaki Kotani, Kazunari Yoshizawa, Jieun Jung, Shunichi Fukuzumi, Takahiko Kojima

DALTON TRANSACTIONS Vol. 49 ( 47 ) page： 17230 - 17242 2020.12

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

A Ru-II complex, [Ru-II(tpphz)(bpy)(2)](2+) (1) (tpphz = tetrapyridophenazine, bpy = 2,2 '-bipyridine), whose tpphz ligand has a pyrazine moiety, is converted efficiently to [Ru-II(tpphz-HH)(bpy)(2)](2+) (2) having a dihydropyrazine moiety upon photoirradiation of a water-methanol mixed solvent solution of 1 in the presence of an electron donor. In this reaction, the triplet metal-to-ligand charge-transfer excited state ((MLCT)-M-3*) of 1 is firstly formed upon photoirradiation and the (MLCT)-M-3* state is reductively quenched with an electron donor to afford [Ru-II(tpphz(-))(bpy)(2)](+), which is converted to 2 without the observation of detectable reduced intermediates by nano-second laser flash photolysis. The inverse kinetic isotope effect (KIE) was observed to be 0.63 in the N-H bond formation of 2 at the dihydropyrazine moiety. White-light (380-670 nm) irradiation of a solution of 1 in a protic solvent, in the presence of an electron donor under an inert atmosphere, led to photocatalytic H-2 evolution and the hydrogenation of organic substrates. In the reactions, complex 2 is required to be excited to form its (MLCT)-M-3* state to react with a proton and aldehydes. In photocatalytic H-2 evolution, the H-H bond formation between photoexcited 2 and a proton is involved in the rate-determining step with normal KIE being 5.2 on H-2 evolving rates. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations on the reaction mechanism of H-2 evolution from the ground and photo-excited states of 2 were performed to have a better understanding of the photocatalytic processes.

DOI： 10.1039/d0dt03546g

Web of Science

Development of Catalytic Reduction of Renewable Carbon Resources Using Well-Elaborated Organometallic Complexes with PNNP Tetradentate Ligands

Shota Yoshioka, Jieun Jung, Susumu Saito

Journal of Synthetic Organic Chemistry, Japan Vol. 78 ( 9 ) page： 856 - 866 2020.9

Development of Catalytic Reduction of Renewable Carbon Resources Using Well-Elaborated Organometallic Complexes with PNNP Tetradentate Ligands

Yoshioka, S; Jung, J; Saito, S

JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN Vol. 78 ( 9 ) page： 856 - 866 2020.9

Photocatalytic CO2 Reduction Using a Robust Multifunctional Iridium Complex toward the Selective Formation of Formic Acid Reviewed

Kenji Kamada, Jieun Jung, Taku Wakabayashi, Keita Sekizawa, Shunsuke Sato, Takeshi Morikawa, Shunichi Fukuzumi, Susumu Saito

Journal of the American Chemical Society Vol. 142 ( 23 ) page： 10261 - 10266 2020.6

Spatiotemporal control of amide radicals during photocatalysis

Shogo Mori, Takahiro Aoki, Kaliyamoorthy Selvam, Shunichi Fukuzumi, Jieun Jung, and Susumu Saito

ChemRxiv. 2020.3

PNNP四座配位子をもつ精密金属錯体触媒を用いる再生可能炭素資源の還元法の開発 Invited Reviewed

有機合成化学協会誌 Vol. 78 page： 856 - 866 2020

Photocatalytic Oxygenation Reactions with a Cobalt Porphyrin Complex Using Water as an Oxygen Source and Dioxygen as an Oxidant International coauthorship

Young Hyun Hong, Ji Won Han, Jieun Jung, Tatsuo Nakagawa, Yong-Min Lee, Wonwoo Nam, Shunichi Fukuzumi

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Vol. 141 ( 23 ) page： 9155 - 9159 2019.6

Photodriven Oxidation of Water by Plastoquinone Analogs with a Nonheme Iron Catalyst International coauthorship

Young Hyun Hong, Jieun Jung, Tatsuo Nakagawa, Namita Sharma, Yong-Min Lee, Wonwoo Nam*, and Shunichi Fukuzumi*

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Vol. 141 ( 16 ) page： 6748 - 6754 2019.4

Long-Lived Photoexcited State of a Mn(IV)-Oxo Complex Binding Scandium Ions That is Capable of Hydroxylating Benzene Reviewed

Namita Sharma, Jieun Jung, Kei Ohkubo, Yong-Min Lee, Mohamed E. El-Khouly, Wonwoo Nam, Shunichi Fukuzumi

Journal of the American Chemical Society Vol. 140 ( 27 ) page： 8405 - 8409 2018.7

Thermal and photocatalytic oxidation of organic substrates by dioxygen with water as an electron source Reviewed

Shunichi Fukuzumi, Yong-Min Lee, Jieun Jung, Wonwoo Nam

Green Chemistry Vol. 20 ( 5 ) page： 948 - 963 2018.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Royal Society of Chemistry

The oxidation of organic substrates is of fundamental importance in nature and includes key transformations in organic synthesis and industry. Dioxygen (O2) is potentially the greenest oxidant because O2 is available in air and its reduction product is water, which is environmentally the most benign substance. However, the direct thermal oxidation of organic substrates with O2 is spin-forbidden because the spin state of ground-state O2 is triplet and the spin state of most organic substrates is singlet. Transition metal complexes can react with triplet O2 in the presence of an electron source to produce metal-oxygen intermediates, such as metal-oxo and metal-hydroperoxo complexes, that can oxidize substrates under mild conditions. Various thermal and photocatalytic mechanisms of the oxidation of organic substrates by O2 with transition metal complexes have been critically discussed by focusing on how metal-oxygen intermediates are produced in the presence of an electron source and then react with organic substrates. Metal-oxygen intermediates are more easily produced by the reactions of metal complexes with hydrogen peroxide (H2O2) and act as active catalysts for the oxidation of substrates by H2O2. The photocatalytic oxidation of water by O2 to produce H2O2 has been combined with the catalytic oxidation of organic substrates by H2O2 to achieve the photocatalytic oxidation of organic substrates by O2. The photocatalytic oxidation of organic substrates by O2 with the use of water as an electron source has also been made possible by the use of inorganic and organic photocatalysts, which can be combined with transition metal complexes as catalysts for thermal reaction steps.

DOI： 10.1039/c7gc03387g

Web of Science

Scopus

Bicyclic Baird-type aromaticity Reviewed

Won-Young Cha, Taeyeon Kim, Arindam Ghosh, Zhan Zhang, Xian-Sheng Ke, Rashid Ali, Vincent M. Lynch, Jieun Jung, Woojae Kim, Sangsu Lee, Shunichi Fukuzumi, Jung Su Park, Jonathan L. Sessler, Tavarekere K. Chandrashekar, Dongho Kim

NATURE CHEMISTRY Vol. 9 ( 12 ) page： 1243 - 1248 2017.12

Language：English Publishing type：Research paper (scientific journal) Publisher：NATURE PUBLISHING GROUP

Classic formulations of aromaticity have long been associated with topologically planar conjugated macrocyclic systems. The theoretical possibility of so-called bicycloaromaticity was noted early on. However, it has yet to be demonstrated by experiment in a simple synthetic organic molecule. Conjugated organic systems are attractive for studying the effect of structure on electronic features. This is because, in principle, they can be modified readily through dedicated synthesis. As such, they can provide useful frameworks for testing by experiment with fundamental insights provided by theory. Here we detail the synthesis and characterization of two purely organic non-planar dithienothiophene-bridged [ 34] octaphyrins that permit access to two different aromatic forms as a function of the oxidation state. In their neutral forms, these congeneric systems contain competing 26 and 34 pi-electronic circuits. When subject to two-electron oxidation, electronically mixed [4n+1]/[4n+1] triplet biradical species in the ground state are obtained that display global aromaticity in accord with Baird's rule.

DOI： 10.1038/NCHEM.2834

Web of Science

Photocatalytic oxidation of benzene to phenol using dioxygen as an oxygen source and water as an electron source in the presence of a cobalt catalyst Reviewed

Han Ji Won, Jung Jieun, Lee Yong-Min, Nam Wonwoo, Fukuzumi Shunichi

CHEMICAL SCIENCE Vol. 8 ( 10 ) page： 7119-7125 2017.10

Multi-Electron Oxidation of Anthracene Derivatives by Nonheme Manganese(IV)-Oxo Complexes Reviewed

Namita Sharma, Jieun Jung, Yong-Min Lee, Mi Sook Seo, Wonwoo Nam, Shunichi Fukuzumi

CHEMISTRY-A EUROPEAN JOURNAL Vol. 23 ( 29 ) page： 7125 - 7131 2017.5

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Six-electron oxidation of anthracene to anthraqui-none by a nonheme Mn-IV-oxo complex, [(Bn-TPEN)Mn-IV(O)] (2+), proceeds through a rate-determining electron transfer from anthracene to [(Bn-TPEN) Mn-IV(O)](2+), followed by subsequent fast oxidation reactions to give anthraquinone. The reduced Mn-II complex ([(Bn-TPEN) Mn-II](2+)) is oxidized by [(Bn-TPEN)Mn-IV(O)](2+) rapidly to produce the mu-oxo dimer ([(Bn-TPEN)Mn-III- O-Mn-III(Bn-TPEN)](4+)). The oxygen atoms of the anthraquinone product were found to derive from the manganese-oxo species by the O-18-labelling experiments. In the presence of Sc3+ ion, formation of an anthracene radical cation was directly detected in the electron transfer from anthracene to a Sc3+ ion-bound Mn-IV(O) complex, [(Bn-TPEN)Mn-IV( O)-(Sc(OTf)(3))(2)](2+), followed by subsequent further oxidation to yield anthraquinone. When anthracene was replaced by 9,10-dimethylanthracene, electron transfer from 9,10-dimethylanthracene to [(Bn-TPEN) Mn-IV(O)-(Sc(OTf)(3))(2)](2+) occurred rapidly to produce stable 9,10-dimethylanthracene radical cation. The driving force dependence of the rate constants of electron transfer from the anthracene derivatives to [(Bn-TPEN) Mn-IV(O)](2+) and [(Bn-TPEN) Mn-IV(O)-(Sc(OTf)(3))(2)](2+) was well-evaluated in light of the Marcus theory of electron transfer.

DOI： 10.1002/chem.201700666

Web of Science

Effects of Lewis Acids on Photoredox Catalysis Reviewed

Shunichi Fukuzumi, Jieun Jung, Yong-Min Lee, Wonwoo Nam

ASIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 6 ( 4 ) page： 397 - 409 2017.4

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

The reactivity of organic photoredox catalysts in oxidation reactions is enhanced by the addition of Lewis acids, which bind to the catalyst to increase its oxidizing ability. Redox-inactive metal ions, such as Sc3+, also act as Lewis acids and can bind to flavins to increase their one-electron reduction potentials and photocatalytic stability. The Sc3+ ion can bind to acridine and pyrene to enhance their photoredox catalytic activity in the oxidation of substrates by dioxygen. The binding of Lewis acids to radical anions enhances their overall photocatalytic activity by prohibiting a back electron transfer from the radical anions of substrates to the oxidized photocatalysts. The photocatalytic asymmetric oxidation of terminal olefins by using water as the oxygen source with a mononuclear nonheme chiral manganese complex has been made possible by the addition of acetic acid, which is essential to afford the products with high enantioselectivity.

DOI： 10.1002/ajoc.201600576

Web of Science

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