Search Institutional Repository


Associate Professor

Laboratory location

Sugimoto Campus

Degree 【 display / non-display

  • Osaka City University -  Doctor of Science

Research Areas 【 display / non-display

Inorganic chemistry, Functional solid state chemistry

Research Career 【 display / non-display

  • Development of catalysts for electrochemical reduction of carbon dioxide using suifido-bridged multimetallic cluster compounds

    (Individual) Project Year :


    Keyword in research subject:  multimetallic cluster, reduction of carbon dioxide, catalysts

  • Sugar-Coated N-heterocyclic carbene complexes

    (Individual) Project Year :


    Keyword in research subject:  transition metal complex, saccharide, carbene

Association Memberships 【 display / non-display

  • American Chemical Society

  • Society of Pure and Applied Coordination Chemistry

  • Chemical Society of Japan

Committee Memberships 【 display / non-display

  • 2016

    Society of Pure and Applied Coordination Chemistry  

  • 2010

    Society of Pure and Applied Coordination Chemistry  

  • 2007

    Society of Pure and Applied Coordination Chemistry  

Current Career 【 display / non-display

  • Osaka City University   Graduate School of Science   Molecular Materials Science Course   Associate Professor  

Career 【 display / non-display

  • 2007

    Osaka City University  

  • 2006

    Osaka City University  

  • 1996

    Osaka City University  

  • 1995

    Osaka City University  

Graduate School 【 display / non-display


    Osaka City University  Graduate School, Division of Natural Science 


Published Papers 【 display / non-display

  • Sugar-Incorporated Chelating Bis-N-Heterocyclic Carbene Palladium Complexes. Synthesis, Structures, and Catalytic Ability for Suzuki-Miyaura Cross-Coupling Reactions in Water

    Imanaka Yosuke, Nakao Keita, Maeda Yuri, Nishioka Takanori

    公益社団法人 日本化学会 BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN  90 ( 9 ) 1050 - 1057 2017.09  [Refereed]

     View Summary

    <p>Sugar-incorporated chelating bis-N-heterocyclic carbene ligand precursors 1,1′-bis(2,3,4,6-tetra-<i>O</i>-acetyl-β-<span style="font-variant: small-caps;">d</span>-glucopyranosyl)-3,3′-ethylene-diimidazolyl ([(bisNHC-C2)H<sub>2</sub>]<sup>2+</sup>) and 1,1′-bis(2,3,4,6-tetra-<i>O</i>-acetyl-β-<span style="font-variant: small-caps;">d</span>-glucopyranosyl)-3,3′-propylene-diimidazolyl ([(bisNHC-C3)H<sub>2</sub>]<sup>2+</sup>) were synthesized and used to prepare palladium complexes [Pd(bisNHC-C2)Cl<sub>2</sub>] and [Pd(bisNHC-C3)Cl<sub>2</sub>], respectively, by direct metallation reaction using dichlorobis(acetonitrile)palladium as a metal source. Catalytic abilities of the complexes for Suzuki-Miyaura coupling in aqueous media were examined and moderate TON (85,000) and TOF (170,000 h<sup>−1</sup>) were obtained. Because the terminal chloro ligands in the complexes were substituted with solvent molecules or chloride anion and hence <sup>1</sup>H NMR spectra of the chloro complexes were complicated, hydrosulfido complexes [Pd(bisNHC-C<i>n</i>)(SH)<sub>2</sub>] (<i>n</i> = 2 and 3) were prepared to confirm structures in solution. Dynamic behavior of flapping-wing motion of the bisNHC ligand in [Pd(bisNHC-C3)(SH)<sub>2</sub>] in solution was evaluated using the signals of the SH protons, which are inequivalent in <sup>1</sup>H NMR spectra attributed to the chirality of the glucopyranosyl units.</p>

    DOI CiNii

  • The Arrangement of Two N-Heterocyclic Carbene Moieties in Palladium Pincer Complexes Affects Their Catalytic Activity towards Suzuki-Miyaura Cross-Coupling Reactions in Water

    Imanaka Yosuke, Shiomoto Naotoshi, Tamaki Mako, Maeda Yuri, Nakajima Hiroshi, Nishioka Takanori

    公益社団法人 日本化学会 BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN  90 ( 1 ) 59 - 67 2017.01  [Refereed]

     View Summary

    <p>Palladium complexes with pincer ligands containing one pyridine and two N-heterocyclic carbene units with acetyl-protected <span style="font-variant: small-caps;">d</span>-glucopyranosyl groups in C-C-N and C-N-C arrangements were synthesized. The complexes form diastereomers due to the twisted pincer ligands and chiral <span style="font-variant: small-caps;">d</span>-glucopyranosyl units. The diastereomers of the C-C-N complex are in equilibrium in solution, whereas only one of the diastereomers of the C-N-C complex forms kinetically. Deprotection of the acetyl groups in the ligands afforded water-soluble complexes with one of the hydroxide groups in the <span style="font-variant: small-caps;">d</span>-glucopyranosyl groups coordinated to the metal ion. In CD<sub>3</sub>OD, the deprotected complex with the C-N-C ligand gradually decomposed, whereas that with the C-C-N ligand was stable at room temperature. The complexes catalyzed Suzuki–Miyaura cross-coupling reactions in water with turnover numbers of 75,000 for the C-C-N and 8,900 for C-N-C complexes. The C-C-N complex was not deactivated by the addition of metallic Hg meaning that the active species is the complex itself or its derivatives having the pincer ligand. On the other hand, the C-N-C complex exhibited no catalytic activity for the coupling reaction in the presence of metallic Hg, meaning that the active species are heterogeneous catalysts, such as Pd nanoparticles.</p>

    DOI CiNii

  • Observation of hybrid artificial photosynthetic membranes using peripheral and core antennae from two different species of photosynthetic bacteria by AFM and fluorescence micro-spectroscopy

    Uragami Chiasa, Sugai Yuko, Hanjo Kohei, Sumino Ayumi, Fujii Ritsuko, Nishioka Takanori, Kinoshita Isamu, Dewa Takehisa, Nango Mamoru, Gardiner Alastair T., Cogdell Richard J., Hashimoto Hideki



  • Syntheses and Catalytic Ability of Sugar-Incorporated N-Heterocyclic Carbene Pincer Pd Complexes Possessing Various N-Substituents

    Imanaka Yosuke, Hashimoto Hideki, Nishioka Takanori

    公益社団法人 日本化学会 BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN  88 ( 8 ) 1135 - 1143 2015.08  [Refereed]

     View Summary

    Exploration of catalysts for organic reactions in water, which is a nontoxic and nonexplosive liquid, has been studied to achieve environmentally friendly chemical processes. For such a purpose, we utilized click chemistry to incorporate sugar units into transition-metal complexes affording water-soluble complexes. In this study, a series of palladium complexes with C&ndash;C&ndash;N pincer ligands, each of which consisted of two <i>N</i>-heterocyclic carbenes (NHCs) and a triazole moiety with a <small>D</small>-glucopyranosyl unit were synthesized. These complexes possess various <i>N</i>-substituents, namely, methyl, isopropyl, benzyl, or <small>D</small>-glucopyranosyl units on the terminal NHC moieties. The diastereoselectivity in the formation of the complexes and their catalytic ability toward the Suzuki&ndash;Miyaura cross-coupling reactions in water exhibited clear <i>N</i>-substituent effects. The tridentate ligand with an acetylated <small>D</small>-glucopyranosyl unit on the terminal NHC moiety led to high diastereoselectivity in the formation of its complex, while each of the other ligands with achiral substituents on the terminal NHC units afforded both of the diastereomers with low selectivity. Catalytic reactions using the complexes were examined for the Suzuki&ndash;Miyaura cross-coupling reactions of phenylboronic acid and 4&prime;-bromoacetophenone in water. The complex possessing an isopropyl group on the terminal NHC moiety exhibited excellent catalytic activity with TON (800000), which is comparable to the best value reported for a similar reaction.

    DOI CiNii

  • Redox Properties and Catalytic Ability toward Electrochemical Proton Reduction of Sulfur-Bridged Trinuclear Mo3S4 Complexes Containing Acetate, Trifluoroacetate, and/or Dithiophosphate as Bridging Ligands

    Kawamoto Keisuke, Ichimura Akio, Hashimoto Hideki, Kinoshita Isamu, Hirotsu Masakazu, Nishioka Takanori

    公益社団法人 日本化学会 BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN  88 ( 4 ) 565 - 571 2015.04  [Refereed]

     View Summary

    A novel complex with the terminal acetonitrile and bridging trifluoroacetate (tfa) ligands of [Mo<sub>3</sub>S<sub>4</sub>(dtp)<sub>3</sub>(&mu;-tfa)(NCCH<sub>3</sub>)] (dtp: diethyl dithiophospate) (<b>1-tfa</b>) was prepared from the substitution reaction of [Mo<sub>3</sub>S<sub>4</sub>(dtp)<sub>3</sub>(&mu;-dtp)(NCCH<sub>3</sub>)] (<b>1-dtp</b>) with trifluoroacetate anhydride in acetonitrile. The reaction of <b>1-dtp</b> with trifluoroacetic acid in dichloromethane also afforded <b>1-tfa</b>. Complex <b>1-tfa</b> reacts with pyridine in ethanol resulting in the formation of a complex with the terminal pyridine ligand (py), [Mo<sub>3</sub>S<sub>4</sub>(dtp)<sub>3</sub>(&mu;-tfa)(py)] (<b>2-tfa</b>). Structures of <b>1-tfa</b> and <b>2-tfa</b> were determined by single-crystal X-ray structural analysis showing that one of three Mo&ndash;Mo distances depend on a kind of the bridging ligands, dtp, OAc, and tfa, while no trends in the other two Mo&ndash;Mo distances in each of the complexes with the different bridging ligands. Each of the cyclic voltammograms of <b>1-dtp</b>, [Mo<sub>3</sub>S<sub>4</sub>(dtp)<sub>3</sub>(&mu;-OAc)(NCCH<sub>3</sub>)] (OAc: acetate) (<b>1-OAc</b>), <b>1-tfa</b>, [Mo<sub>3</sub>S<sub>4</sub>(dtp)<sub>3</sub>(&mu;-OAc)(py)] (<b>2-OAc</b>), and <b>2-tfa</b> showed two consecutive one-electron reduction waves and an oxidation wave, which are formally assigned to the Mo(IV IV IV)/Mo(III IV IV), Mo(III IV IV)/Mo(III III IV), and Mo(V IV IV)/Mo(IV IV IV) couples, respectively. The re-oxidation and re-reduction peaks for the second reduction and the oxidation processes were not observed for all of the complexes. The redox potentials of the first reduction processes were shifted up to ca. 200 mV with the bridging and terminal ligands, for example, the redox potentials appeared at &minus;0.98 and &minus;1.19 V vs. Fc/Fc<sup>+</sup> <b>2-OAc</b> and <b>1-tfa</b>, respectively, due to the lower electron-donating ability of CH<sub>3</sub>CN and tfa ligands compared to that of the py and OAc ligands. The re-oxidation peak for the second reduction process of <b>2-OAc</b> was observed at &minus;80 &deg;C suggesting that this is an EC process and the chemical reaction following the second electrochemical reduction is probably inhibited at low temperature. On the other hand, no re-reduction peak for the oxidation process appeared even at &minus;80 &deg;C implying that the oxidation process is accompanied by a significant structural change. This argument is supported by the results of the DFT calculation. The HOMO component of the complex contains a bonding character between the two acetate-bridged Mo centers and the other acetate-unbridged one, and the spin densities of the 1-electron oxidized complex mostly located at the one of two acetate-bridged Mo centers and the other acetate-unbridged one. Cyclic voltammograms of these complexes in the presence of trifluoroacetic acid as a proton source exhibited catalytic currents around the first reduction wave for each complex. The DFT calculations for <b>2-OAc</b> and <b>2-tfa</b> demonstrated that the HOMO components are also distributed over the doubly bridged sulfur ligands in addition to the Mo centers in the Mo<sub>3</sub>S<sub>4</sub> core. These result suggests that a protonation reaction of <b>2-OAc</b> and <b>2-tfa</b> probably occurs on the doubly bridged sulfur ligand in the Mo<sub>3</sub>S<sub>4</sub> core.

    DOI CiNii

display all >>

Books etc 【 display / non-display