Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 87 , Issue 3
Showing 1-12 articles out of 12 articles from the selected issue
Award Accounts
The Chemical Society of Japan Award for Creative Work for 2012
  • Toshinori Suzuki
    2014 Volume 87 Issue 3 Pages 341-354
    Published: March 15, 2014
    Released: March 15, 2014
    JOURNALS FREE ACCESS
    Nonadiabatic electronic dynamics contribute to the diversity of chemical reactions. We investigate nonadiabatic dynamics in isolated molecules and aqueous solutions by time-resolved photoelectron spectroscopy. For isolated molecules in the gas phase, we combine two-dimensional imaging detection of electrons and a sub-20 fs deep UV and vacuum UV light source to measure time-evolution of the photoelectron kinetic energy and angular distributions. Time–energy mapping of photoelectron angular anisotropy reveals the S2 → S1 internal conversion dynamics through conical intersection in pyrazine, benzene, and toluene. The time–energy mapping is also employed to extract the photoelectron angular distribution in the molecular frame for nitric oxide. For electronic dynamics in aqueous solution, we employ time-resolved photoelectron spectroscopy using a liquid beam and an electrostatic or a time-of-flight electron energy analyzer. Successful observation of ultrafast electron-transfer reactions in aqueous solutions and measurement of electron binding energies of solvated species suggest promising future developments of this very young field.
    Nonadiabatic transition between potential energy surfaces creates the diversity of chemical reactions. Ultrafast photoelectron spectroscopy has enabled real-time observation of electronic dynamics in isolated molecules, and its frontier is now extended to aqueous solution. Fullsize Image
     
The Chemical Society of Japan Award for Creative Work for 2010
  • Reizo Kato
    2014 Volume 87 Issue 3 Pages 355-374
    Published: March 15, 2014
    Released: March 15, 2014
    JOURNALS FREE ACCESS
    Molecular conductors based on [M(dmit)2] (M = Ni and Pd) present a variety of π electron systems that pave the way for a higher stage of solid-state science. Supramolecular interactions between [Ni(dmit)2] anion and halogen-containing cations provide bilayer systems that are characterized by coexistence of two crystallographically independent anion layers with different molecular arrangements and contrasting (for example, metal/insulator and ferromagnetic/antiferromagnetic) properties. In [Pd(dmit)2] salts in the Mott insulating state, a small energy difference between HOMO and LUMO coupled with strong dimerization affords HOMO–LUMO band inversion. The dimer units [Pd(dmit)2]2 form a triangular lattice, and interplay of strong electron correlation and spin frustration generates a wide variety of magnetic/charge states including antiferromagnetic long-range order, quantum spin liquid, charge order, and valence bond order, depending on counter cations. The cation dependence is attributed to a systematic arch-shaped molecular distortion that tunes the anisotropy of interdimer transfer integrals. This means that the [Pd(dmit)2] molecular skeleton is sufficiently flexible within the crystal field, and molecular degrees of freedom play an important role in fine tuning of the electronic state.
    Anion radical salts based on the metal dithiolene complex [M(dmit)2] (M = Ni and Pd) present a variety of π electron systems that go beyond the framework of conventional molecular conductors, depending on the selection of counter cation. Fullsize Image
     
The Chemical Society of Japan Award for Young Chemists for 2007
  • Yuichi Negishi
    2014 Volume 87 Issue 3 Pages 375-389
    Published: March 15, 2014
    Released: March 15, 2014
    [Advance publication] Released: November 21, 2013
    JOURNALS FREE ACCESS
    Advances in developments in nanotechnology have encouraged the creation of highly functionalized nanomaterials. Thiolate-protected gold clusters (Aun(SR)m) less than 2 nm in size exhibit size-specific physical and chemical properties not observed in bulk metals. Therefore, they have attracted attention as functional units or building blocks in nanotechnology. The highly stable, magic Aun(SR)m clusters possess great potential as new nanomaterials. We are studying the following subjects related to magic Aun(SR)m clusters: (1) establishing methods to enhance their functionality, (2) developing high-resolution separation methods, and (3) utilizing the clusters as active sites in photocatalytic materials. Through these studies, we aim to create highly functional metal nanoclusters and apply them as highly active photocatalytic materials. The results of our efforts to date are summarized in this paper.
    Thiolate-protected gold clusters (Aun(SR)m) possess great potential as new nanomaterials. This paper summarizes our efforts to date toward the creation of highly functional metal nanoclusters and highly active photocatalytic materials using magic Aun(SR)m clusters. Fullsize Image
     
BCSJ Award Article
  • Toshiaki Matsubara, Nozomi Araida, Daichi Hayashi, Hatsumi Yamada
    2014 Volume 87 Issue 3 Pages 390-399
    Published: March 15, 2014
    Released: March 15, 2014
    JOURNALS FREE ACCESS
    The oxetane and the non-oxetane mechanisms of the electron-transfer-driven repair of the (6–4) T–T photolesion of DNA by photolyase are examined by density functional theory (B3LYP). We calculated the radical cation pathway in addition to the radical anion and the neutral pathways for both mechanisms in order to assess the possibility of the radical cation pathway, because relatively large energy barriers have been found for the radical anion pathway. As a result, the radical anion pathway showed a large energy barrier in both the oxetane and the non-oxetane mechanisms in agreement with previous calculations. However, it was found that the radical cation pathway of the oxetane mechanism has a realistic low energy barrier. This advantage of the radical cation pathway was ascribed to the position of the radical before the formation of the oxetane and the stability of the oxetane in energy.
    The mechanism of the electron-transfer-induced repair of the (6–4) photoproduct of DNA by photolyase was examined by density functional theory. As a result, the radical cation pathway of the oxetane mechanism was found to be the most favorable in energy. Fullsize Image
     
 
  • Yongbo Zhou, Jia Yang, Tieqiao Chen, Shuang-Feng Yin, Daoqing Han, Li- ...
    2014 Volume 87 Issue 3 Pages 400-402
    Published: March 15, 2014
    Released: March 15, 2014
    [Advance publication] Released: December 17, 2013
    JOURNALS RESTRICTED ACCESS
    Copper-catalyzed stereospecific oxidative dehydrocouplings of P(O)–H bonds with amines under air took place efficiently at room temperature to afford the corresponding amidophosphorus compounds in high yields. Mechanistic studies showed that this dehydrocoupling reaction proceeded stereospecifically with inversion of stereochemistry at phosphorus.
  • Wataru Murakami, Kazuo Eda, Masahiro Yamamoto, Toshiyuki Osakai
    2014 Volume 87 Issue 3 Pages 403-411
    Published: March 15, 2014
    Released: March 15, 2014
    [Advance publication] Released: December 25, 2013
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    A non-Bornian model for understanding the Gibbs energy of ion hydration (Δ Ghyd ° ) has been proposed, in which only short-range interactions between an ion and solvent molecules adjacent to the ion are considered, while the long-range electrostatic interaction between the ion and the outer bulk solvent is not explicitly included in the model. As the short-range interactions, Coulomb, polarization, and charge-transfer interactions are taken into account. It has thus been shown that the Δ Ghyd ° scaled by the solvent-accessible surface (SAS) area of an ion can be given by a quadratic function of the electric field strength E at the SAS. Regression analyses with the derived analytical equation have been performed for the literature values of Δ Ghyd ° for spherical ions, including 85 cations (with the charge number, z = 1 to 4) and 53 anions (with z = −1 and −2); good fitting results have been obtained for either the cations or the anions. An additional regression analysis has been performed for 10 representative cations, using the data set employed by Koehl et al. (J. Phys. Chem. B 2009, 113, 5694). Our non-Bornian model has been found to be one of the highest performance models for the prediction of Δ Ghyd ° .
  • Keita Takezawa, Yoshihisa Matsui, Tatsuyuki Yamamoto, Keisuke Yoshikiy ...
    2014 Volume 87 Issue 3 Pages 412-416
    Published: March 15, 2014
    Released: March 15, 2014
    [Advance publication] Released: December 25, 2013
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    Three structural isomers of monoguanidino-modified α-cyclodextrin (CD), i.e., mono(6-deoxy-6-guanidino)-α-CD (1), mono(3-deoxy-3-guanidino)-α-CD (2), and mono(3-deoxy-3-guanidino-altro)-α-CD (3), were synthesized to study equilibria for the formation of inclusion complexes with the p-nitrophenolate ion (p-NP). The binding constants (Ka’s) for the equilibria, determined by UV–vis titration at 298 K and pH 10.6, showed that 1 with a positively charged guanidino group on the primary hydroxy side of α-CD binds the negatively charged p-NP more strongly than the native α-CD. On the contrary, either 2 or 3, with the same functional group on the secondary hydroxy side, binds p-NP less strongly than the native α-CD. The Ka values for 1, 2, and 3 decreased, while that for the native α-CD remained virtually constant, with increasing ionic strength of the solutions. The two-dimensional 1H NMR spectra of rotating frame nuclear overhauser effect spectroscopy showed that p-NP included in the cavity of 1, 2, 3, or α-CD directs the nitro group toward the primary hydroxy side of the host. These results were explained on the basis of electrostatic interaction, including charge–charge, charge–dipole, and dipole–dipole interaction, between the hosts and the guest.
  • Yin-Nan Yan, Kazuya Kubo, Shin-ichiro Noro, Tomoyuki Akutagawa, Takayo ...
    2014 Volume 87 Issue 3 Pages 417-419
    Published: March 15, 2014
    Released: March 15, 2014
    [Advance publication] Released: January 07, 2014
    JOURNALS RESTRICTED ACCESS
    Supramolecular cation salt of adamantane rotator with a dithiolene complex, (fluoroadamantylammonium+)([18]crown-6)[Ni(dmit)2] (1) was synthesized. The fluorine atom of the adamantane unit showed a large thermal factor elongated latitudinally, suggesting molecular rotation in the solid state. Crystal 1 exhibited a large dielectric response by applying an AC field along the a axis.
  • Anna Ju, Huiyun Seo, Heemun Kim, Byoung Chul Park, Sung Goo Park, Jeon ...
    2014 Volume 87 Issue 3 Pages 420-424
    Published: March 15, 2014
    Released: March 15, 2014
    [Advance publication] Released: December 25, 2013
    JOURNALS RESTRICTED ACCESS
    The Src homology 2 (SH2) domain-containing phosphatase 2 (SHP-2) is a nonreceptor protein tyrosine phosphatase (PTP) involved in extracellular-regulated kinase (ERK) activation. Recent studies have shown that gain-of-function mutations in SHP-2 are associated with several diseases, including LEOPARD syndrome, Noonan syndrome, and juvenile myelomonocytic leukemia. In this study, we identified the novel SHP-2 inhibitor 3-(1-benzimidazolylmethyl)-6-p-tolyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole (MLS-001). SHP-2 activity was inhibited by MLS-001, whereas other types of PTPs, namely ACP1, CDC25A, DUSP3, DUSP14, DUSP18, DUSP22, DUSP23, DUSP26, and SSH3, were not. Furthermore, TCPTP and SHP-1 that are closely related to SHP-2 were not inhibited by the inhibitor. Kinetic studies with MLS-001 and SHP-2 revealed a competitive inhibition. The SHP-2 expressing cells treated with MLS-001 demonstrated reduced SHP-2 phosphatase activity, thereby suggesting that MLS-001 effectively passes through cell membranes. In addition, MLS-001 reduced SHP-2-mediated phosphorylation in the activation loop of ERK in cells. Therefore, MLS-001 could be a lead compound for developing a potent SHP-2 inhibitor.
  • Kentaro Tomita, Toshio Ishioka, Akira Harata
    2014 Volume 87 Issue 3 Pages 425-434
    Published: March 15, 2014
    Released: March 15, 2014
    [Advance publication] Released: December 12, 2013
    JOURNALS RESTRICTED ACCESS
    This article shows that a difference in the building blocks of the molecular framework, C–C to S–S, results in a significant influence on its optical properties. Acyclic anion receptors, bis{2-[3-(substituted)thioureido]ethyl} disulfides were newly synthesized, and their optical properties in response to complex formation with an acetate ion were compared with those of a hexamethylene framework between two thioureido groups. Quantum chemical calculations suggested that receptors fold their molecular framework around disulfide because of the presence of the intramolecular hydrogen bonding between two N,N′-disubstituted thioureas. The complex of the receptor and the acetate ion with 1:1 stoichiometry consists of the coordination of two thioureido groups to the acetate via hydrogen bonds. This complex formation is accompanied by a dissociation of intramolecular hydrogen bonding and rotation of one side of the thioureido group. These circumstances of conformational changes in the molecular framework functioned by switching on and off the excimer fluorescence of the 1-pyrenylmethyl derivative.
  • Xiuren Wang, Jie Zhang, Yan Liu, Yong Cui
    2014 Volume 87 Issue 3 Pages 435-440
    Published: March 15, 2014
    Released: March 15, 2014
    JOURNALS FREE ACCESS
    Two chiral porous organic polymers (CPOPs) were synthesized by linking a TADDOL-embedded building block with arylethynylenes units. The CPOPs are highly stable to thermal treatment, moisture, acidity, and basicity. The dihydroxy groups of TADDOL inside the pores promise the CPOPs as good asymmetric catalysts after postsynthesis modification with a secondary metal center. After being treated with Ti(OiPr)4, the CPOPs could be used as highly effective and reusable heterogeneous catalyst for asymmetric diethylzinc addition to aldehydes with up to 99% conversion and 95% ee. This work promises the potential of generating chiral solid catalysts with unique and practically useful enantioselective functions via a modular approach.
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