Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 80 , Issue 6
Showing 1-25 articles out of 25 articles from the selected issue
Vol. 80 Commemorative Accounts
  • Zhenfeng Xi
    2007 Volume 80 Issue 6 Pages 1021-1032
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS FREE ACCESS
    In this account, our recent results on the application of substituted 1-lithio-1,3-dienes as building blocks for the preparation of a wide variety of cyclic compounds and linear compounds are briefly summarized. Results have revealed that the essential factor which makes 1-lithio-1,3-diene derivatives useful and unique as building blocks is the intra-cooperation between the alkenyllithium moiety and the butadienyl skeleton, notwithstanding that the alkenyllithium moiety itself reacts with organic substrates in the usual way. In addition, the substitution patterns and the nature of the substituents on the butadienyl skeleton have been demonstrated to affect remarkably the reaction pathways of 1-lithio-1,3-diene derivatives.
    The application of substituted 1-lithio-1,3-dienes as building blocks for the preparation of cyclic compounds and linear compounds are briefly summarized. Results have revealed that the essential factor which makes 1-lithio-1,3-diene derivatives useful and unique as building blocks is the intra-cooperation between the alkenyllithium moiety and the butadienyl skeleton. Fullsize Image
  • Kalyanasis Sahu, Sudip Kumar Mondal, Subhadip Ghosh, Kankan Bhattachar ...
    2007 Volume 80 Issue 6 Pages 1033-1043
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS FREE ACCESS
    Ultrafast chemical dynamics in a nano-confined system is very different from that in a bulk liquid. In this account, we give an overview on recent femtosecond study on dynamics of ultrafast chemical processes in the nanocavity of a biological system. Dynamics in a biological system crucially depends on the location of the fluorescent probe. We show that one can study solvation dynamics in different regions (i.e. spatially resolve) by variation of the excitation wavelength. We discuss two interesting cases of how structure affects dynamics. First, solvation dynamics of two protein folding intermediates of cytochrome c is found to be differ significantly in the ultrafast initial part (< 20 ps). Second, methyl substitution of the OH group in a cyclodextrin is shown to slow down the initial part of solvation dynamics quite dramatically. The most interesting observation is the discovery of the ultraslow component of solvation dynamics which is 100–1000 times slower compared to bulk water. The electron- and proton-transfer processes in a nano-confined system are found to be markedly retarded because of slow solvation and structural constraints. Close proximity of the reactants in a confined system is expected to accelerate dynamics of bi-molecular processes. This is illustrated by ultrafast fluorescence resonance energy transfer (FRET) in ≈1 ps time scale between a donor and an acceptor in a micelle. Finally, it is demonstrated that the decay of fluorescence anisotropy provides structural information (e.g. size of a cyclodextrin inclusion complex) and may be used to detect formation of a nano-aggregate.
    Dynamics of ultrafast chemical processes in a nanocavity is studied using femtosecond emission spectroscopy. Dynamics in a nano-confined system differs markedly from that in a bulk liquid. This has implication in many biological processes. Fullsize Image
  • Rajesh Bhosale, Sheshanath Bhosale, Guillaume Bollot, Virginie Gorteau ...
    2007 Volume 80 Issue 6 Pages 1044-1057
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS FREE ACCESS
    The creation of functional materials such as ion channels, porous sensors, or smart photosystems depends critically on our ability to assemble sophisticated, error-free and self-repairing nanoarchitecture in a predictable manner. To address these challenging topics, we often used lipid bilayer membranes as compartmentalizing platform and have introduced rigid-rod molecules as privileged scaffolds that bypass all folding problems because they do not fold. This approach provides access to motifs such as rigid-rod barrels, helices, stacks, slides, and wires that can act as smart, stimuli-responsive photosystems, pores, ion channels, hosts, sensors, and catalysts. The selected examples focus on naphthalenediimides (NDIs), a compact, organizable, colorizable, and functionalizable n-semiconductor. This versatile module is used in rigid-rod molecules to mediate transmembrane anion transport by anion–π interactions, as sticky π-clamp within pore sensors to catch otherwise elusive analytes by aromatic electron donor–acceptor interactions, or in blue, transmembrane π-stack architecture to collect and convert photonic energy. These specific examples with multifunctional NDI nanoarchitecture are of help to outline, on the one hand, possibilities to contribute to advanced functional materials such as multianalyte sensors or solar cells and, on the other hand, to keep on wondering about an enormous structural and functional space waiting to be explored.
    We describe the construction of nanobarrels (figure), helices, stacks, slides, and wires using lipid bilayers as platform, rigid-rod molecules as scaffolds, and naphthalenediimides as multifunctional modules to gain access to advanced functions such as multianalyte sensing (arrows) or artificial photosynthesis. Fullsize Image
Award Accounts
The Chemical Society of Japan Award for Young Chemists for 2005
  • Masaaki Mitsui, Atsushi Nakajima
    2007 Volume 80 Issue 6 Pages 1058-1074
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS FREE ACCESS
    The present account describes our efforts to understand the microscopic aspects of condense phase phenomena, such as ion solvation in molecular liquids and charge carrier localization in molecular solids, by viewing finite-size molecular clusters as their embryonic forms. In this effort, we efficiently prepared supersonically cooled, isolated molecular cluster anions with up to more than 100 constituent molecules and size-selectively investigated their electronic structures using anion photoelectron spectroscopy. Large anionic clusters of two different types of organic molecule; acetonitrile and naphthalene reported as examples of the noteworthy results obtained in our studies. In these two systems, we found that energetically close anionic isomers coexist over a broad range in size, and their contribution in the photoelectron spectra could be separated using anion beam hole-burning technique. A detailed inspection into the electronic states and size-dependent energetics of each isomer has enabled us to establish a link from the large finite cluster to the infinite bulk system.
    We efficiently prepared supersonically cooled, isolated molecular cluster anions with up to more than 100 constituent molecules and examined their electronic structures step-by-step using anion photoelectron spectroscopy, to reveal the coexistence of isomers in large finite clusters. Fullsize Image
The Chemical Society of Japan Award for Technical Development for 2005
  • Hideaki Tsuneki, Masaru Kirishiki, Tomoharu Oku
    2007 Volume 80 Issue 6 Pages 1075-1090
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS FREE ACCESS
    Ethanolamines are produced on an industrial scale exclusively by the reaction of ethylene oxide with an aqueous solution of ammonia. The reaction is a typical consecutive reaction with three steps; therefore, it is difficult to produce 2,2′-iminodiethanol (the second product of the reaction) with high selectivity by conventional means. We developed a catalytic 2,2′-iminodiethanol selective production process using a pentasil-type zeolite catalyst modified with rare earth elements. This highly active catalyst was able to recognize the difference at molecular level between 2,2′-iminodiethanol and 2,2′,2″-nitrilotriethanol; 2,2′,2″-nitrilotriethanol was not formed in its micropore. We also succeeded in producing a binderless molded zeolite catalyst that does not form problematic impurities and that has a shape suitable for a fixed-bed reactor. The problem of activity deterioration was overcome by developing a regeneration process using high-temperature and high-density ammonia gas as a rinse medium.
    The reaction of ethanolamines formation is a typical consecutive reaction, and therefore, 2,2′-iminodiethanol cannot be produced with high selectivity. A catalytic 2,2′-iminodiethanol selective production process was developed using a pentasil-type zeolite catalyst modified with a rare earth element and a binderless molded zeolite catalyst suitable for a fixed-bed reactor. Fullsize Image
BCSJ Award Article
  • Jusaku Minari, Takanori Kubo, Hideki Ohba, Naohiko Shimada, Yoich Take ...
    2007 Volume 80 Issue 6 Pages 1091-1098
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS FREE ACCESS
    Telomerase, which is highly activated in neoplastic cells, can be a target for antisense therapy, and for that purpose, antisense oligonucleotides (AS ODNs) have to be effectively delivered into cellular nucleus where the target telomerase is present. The present work shows a new strategy to deliver AS ODNs to nucleus by use of a novel complex made from a natural polysaccharide schizophyllan (SPG) and AS ODNs. Nuclear transport is strictly regulated by the nuclear pore size and the related proteins. If the molecular weight of SPG is decreased, the SPG/AS ODN complex should be easily transported, although the stability of the complex decreases with a decrease in the molecular weight. We optimized the molecular weight of SPG to be 25 K. Furthermore, we attached importin-β (a nuclear transport protein) to the side chain of SPG by use of a streptavidin–biotin interaction. When this complex was added to Jurkat cells, the telomerase activity was more suppressed than the naked dose, indicating that the importin-β in the complex induced the nuclear transport of the complexed AS ODN and the AS ODN inhibited the telomerase. The present work shows a new methodology for nuclear anti-sense therapy that should be important in future anti-cancer therapies.
    Schizophyllan (SPG) could form a complex with antisense oligonucleotides (AS ODN). When importin-β, a nuclear transport protein was bound to SPG (through a streptavidin–biotin interaction), the complex was transported into nucleus and inhibited telomerase. Fullsize Image
 
  • Kazutoshi Iwamoto
    2007 Volume 80 Issue 6 Pages 1099-1102
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    A chiral symmetry-breaking reaction model was constructed based on the Oregonator model, which was proposed to explain the oscillatory behavior of the Belousov–Zhabotinskii reaction by Field, Körös, and Noyes. Its symmetry-breaking transition results in the dominance of one enantiomer, and the disappearance of the other. Depending on the parameter values, an asymmetric steady state, symmetric steady state, or oscillatory behavior with either the same or different amplitudes is exhibited. Numerous chemical oscillation systems have been previously reported, and these systems always include autocatalytic processes. Accordingly, if the autocatalyst in these experimental systems has optical isomers and each isomer catalyzes its own production, the spontaneous appearance of a chiral symmetry-breaking state is expected in the chemical oscillation system under the appropriate experimental conditions.
  • Takehiko Satoh, Mitsutaka Kudoh, Takemasa Tsuji, Shouichi Kita, Toshia ...
    2007 Volume 80 Issue 6 Pages 1103-1113
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    The dipole moments of the ground- and excited-states of 1,4-naphthoquinone (1), 2-chloro-1,4-naphthoquinone (2), 2-bromo-1,4-naphthoquinone (3), 2-methyl-1,4-naphthoquinone (4), 2,3-dichloro-1,4-naphthoquinone (5), 2,3-dibromo-1,4-naphthoquinone (6), 2-hydroxy-1,4-naphthoquinone (7), 3-chloro-2-hydroxy-1,4-naphthoquinone (8), 3-bromo-2-hydroxy-1,4-naphthoquinone (9), and 2-hydroxy-3-methyl-1,4-naphthoquinone (10) were studied from both experimental and theoretical perspectives. For the ground states, the dipole moments of compounds 5, 8, and 9 were determined experimentally in dilute solutions (via Debye’s method), and compared with those of the other compounds 14, 6, 7, and 10 which we had already determined. The density functional theory calculations were also performed, revealing a positive correlation with the experimental results. For the excited states, however, the dipole moments of the excited states of compounds 110 have not yet been studied. In this work, we determined the dipole moments of some of the lower excited states of these compounds using the spectroscopic method. Results revealed the determined excited-state dipole moments exceeded those of the ground state, a finding also supported by the configuration interaction involving one-electron excitations only.
  • Hisashi Okumura, Yuko Okamoto
    2007 Volume 80 Issue 6 Pages 1114-1123
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    Multibaric–multithermal (MUBATH) simulation can escape from local-minimum free-energy states, and one can obtain accurate thermodynamic quantities as functions of any temperature and pressure from a single simulation run. We performed a MUBATH molecular dynamics simulation of an alanine dipeptide in explicit water. The MUBATH simulation sampled the states of PII, C5, αR, αP, and αL. On the other hand, the conventional isobaric–isothermal simulation was trapped in local-minimum free-energy states and sampled only a few of them. We calculated the partial molar enthalpy and partial molar volume from the MUBATH simulation. Our results were in accord with those from Raman spectroscopy.
  • Keisuke Yoshikiyo, Yoshihisa Matsui, Tatsuyuki Yamamoto, Yuji Okabe
    2007 Volume 80 Issue 6 Pages 1124-1128
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    The 2,6-naphthalenedicarboxylate ion (2,6-NDC) was included into the interior cavity of 3A,6A-anhydro-β-cyclodextrin (1) in D2O containing 0.1 mol dm−3 Na2CO3 and caused a shift in the 1H NMR signals due to the C3- and C5-H’s of 1 to different directions, depending on the positions of glucose units (anisotropic ring-current effect). The decrease in entropy accompanied by the complexation was much larger than that for the complexation of native β-cyclodextrin with 2,6-NDC. These results indicate that the molecular rotation of 2,6-NDC is retarded within the deformed cavity of 1.
  • Keisuke Matsuoka, Mariko Ishii, Aki Yonekawa, Chikako Honda, Kazutoyo ...
    2007 Volume 80 Issue 6 Pages 1129-1131
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    The size and shape of aggregates were investigated for four fluorinated amphiphiles with different alkyl chain lengths: Cn−1F2n−1CH2N+(CH3)3Cl (Cn-TAC; n = 8, 10, 12, and 14) by TEM. The micrographs showed that Cn-TACs were mostly disc-like or ellipsoid-shaped lamella, which exponentially grew up their size from 10 nm (C8-TAC) to 500 nm (C14-TAC).
  • Nobuhiko Iki, Yusuke Yamane, Naoya Morohashi, Takashi Kajiwara, Tasuku ...
    2007 Volume 80 Issue 6 Pages 1132-1139
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    A systematic investigation was conducted on the structures of tetra- and di-nuclear copper(II) complexes with three stereoisomers of sulfinylcalix[4]arenes (H4L), the isomerism of which is determined by the disposition of the sulfinyl oxygen with respect to a reference oxygen from the mean plane containing four sulfur atoms. The sulfinylcalix[4]arene with a transcistrans S=O orientation (H4Lrtct) reacted with Cu(OAc)2 to form [CuII4(Lrtct)(OAc)3(μ-MeO)(MeOH)] (1), in which Lrtct4− adopts a cone conformation to afford tetrakis fac-tridentate coordination through four phenoxo oxygens and four sulfinyl groups giving a square CuII4 core. Ligands H4Lrccc and H4Lrctt having cisciscis and cistranstrans configurations formed [CuII4(Lrccc)(OAc)3(μ-OH)] (2) and [CuII4(Lrctt)(OAc)3(μ-OH)] (3), respectively, which have common features, such as a cone-type conformation of L4−, tetrakis fac-tridentate coordination fashion, and tetracopper(II) core in a square-pyramidal geometry. The similarities among 13 clearly show that sulfinylcalix[4]arenes can coordinate to CuII in a fac-tridentate fashion via a donor atom X (O or S) from a sulfinyl group and two flanking phenoxo Os and that X is simply determined by the X–Cu distance. Using [Cu(acac)2] as a copper(II) source, H4Lrctt formed [CuII2(H2Lrctt)2] (4), suggesting the significance of auxiliary ligand for bridging copper(II) centers to assemble the core, that is, the acetato ligands in complexes 13 are needed to form the core structure. Metal–metal interactions were investigated by means of magnetic susceptibility, and it was found that both ferro- and antiferromagnetic interactions occur in tetracopper(II) complex 3. In contrast, antiferromagnetic interaction is present in dicopper(II) complex 4.
  • Munetaka Iwamura, Toshiaki Tsukuda, Makoto Morita
    2007 Volume 80 Issue 6 Pages 1140-1147
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    Luminescence and energy-transfer reactions in double complex crystals of [Co(en)3][Tb(dpa)3] (en = ethylenediamine, dpa = 2,6-pyridinedicarboxylate) were investigated and compared to single crystals of rac-[Co(en)3rac-[Tb(dpa)3] (double complexes salt of racemic [Co(en)3]3+ and racemic [Tb(dpa)3]3−) and Δ-[Co(en)3rac-[Tb(dpa)3] (chiral [Co(en)3]3+ and racemic [Tb(dpa)3]3− salt). The energy-transfer rate constants from Tb3+ to Co3+ complexes were determined from the time profile of emission intensity of photo-excited TbIII ion in the double complex crystals. The emission decay profiles of rac-[Co(en)3rac-[Tb(dpa)3] were analyzed with single exponential curves. On the other hand, the profiles of Δ-[Co(en)3rac-[Tb(dpa)3] show double-exponential curves. From the X-ray analysis of crystal structures, it was found that there is only one site for [Tb(dpa)3]3− in rac-[Co(en)3rac-[Tb(dpa)3] crystal, and there are two sites in the Δ-[Co(en)3rac-[Tb(dpa)3] crystal, i.e., Δ-[Tb(dpa)3]3− and Λ-[Tb(dpa)3]3− are put in different sites in the crystal. The two rate constants obtained from the double-exponential curve of Δ-[Co(en)3rac-[Tb(dpa)3] are assigned to energy-transfer rates from Δ-[Tb(dpa)3]3− and Λ-[Tb(dpa)3]3− in the crystal. A distance dependence was determined from the obtained energy-transfer rate constants and the Tb–Co distances in the crystals according to a Dexter type electron-exchange mechanism of energy-transfer model. The energy-transfer rate constants in the crystals are comparable in magnitude with energy-transfer rates in quenching experiments in the [Tb(dpa)3]3−–[Co(en)3]3+ aqueous solution.
  • Yoshiko Yokote, Yoshiko Kubo, Rieko Takahashi, Teruki Ikeda, Kiso Akah ...
    2007 Volume 80 Issue 6 Pages 1148-1156
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    Raman spectra of undeuterated and deuterated rachis from a fowl feather was observed with 488 nm excitation in the 400–1800 cm−1 region. Fowl feather rachis and barbs were subjected to a polarized Raman microscopic examination with excitation at 785 nm. From the observed frequencies, intensities, and scattering anisotropies of the 20 Raman bands, and on the basis of known Raman tensors of the 10 localized molecular vibrations, conformations, and orientations of the polypeptide main chains, tyrosine, phenylalanine, tryptophan residues, and disulfide linkages of the protein molecules in the feather were elucidated.
  • Hirofumi Mukae, Hajime Maeda, Satoshi Nashihara, Kazuhiko Mizuno
    2007 Volume 80 Issue 6 Pages 1157-1161
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    Intramolecular [2+2] and [2+3] photocycloadditions of 2-(2-alkenyloxymethyl)naphthalene-1-carbonitriles and their photocycloreversion using glass-made microreactors were investigated in comparison with photoreactions under conventional batch conditions. Both the efficiency and regioselectivity were improved by use of glass-made microreactors. These results can be explained by thorough absorption of light and outflow of primary product from the reaction system.
  • Yuji Mizobe, Tomoaki Hinoue, Mikiji Miyata, Ichiro Hisaki, Yasuchika H ...
    2007 Volume 80 Issue 6 Pages 1162-1172
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    In order to prepare novel molecular arrangements of a fluorophore that result in new solid-state fluorescence properties, we fabricated a ternary system consisting of anthracene-2,6-disulfonic acid (ADS), aliphatic primary amines and guest molecules as a fluorophore, arrangement-controlling parts and molecular information sources, respectively. The system consisting of ADS, (rac)-s-butylamine and 1,4-dioxane yielded a novel zigzag arrangement of anthracene moieties that gave rise to a rare emission mode. Subsequent screening of the amines and guests in the ternary system suggested that a relationship exists among the molecular information source, the zigzag arrangement and the rare emission mode. Namely, molecular information of 1,4-dioxane is transcribed to the zigzag arrangement, and the arrangement is translated into the excimer-like emission. Interestingly, the relationship appears to mimic that found in DNA. In addition, transcription of the molecular information requires the appropriate shape and size of void spaces formed by ADS and (rac)-s-butylamine. From these observations, the zigzag arrangement and the corresponding rare emission mode is specific for the system of ADS, (rac)-s-butylamine and 1,4-dioxane.
  • Kenshu Fujiwara, Jota Naka, Takahiro Katagiri, Daisuke Sato, Hidetoshi ...
    2007 Volume 80 Issue 6 Pages 1173-1186
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    The synthesis of the A- and F-rings of goniodomin A (1), which is a stereochemically unidentified antifungal agent isolated from dinoflagellate Alexandrium hiranoi, was performed to determine of the relative stereochemistry of these parts. The relative stereochemistry of the A- and F-rings was first deduced from Murakami’s NMR data, and model compounds corresponding to these parts were then synthesized. The synthetic A-ring model, of which the structure was established by X-ray crystallographic analysis, showed good agreement with the natural A-ring on the basis of J and NOE behavior in the 1H NMR spectroscopy. The chemical shifts in 1H and 13C NMR specta and J32-OH–H33 of the synthetic F-ring model having a 33S,34R configuration also agreed with those of the F-ring of 1. Thus, the relative stereochemistry of the A- and F-rings of 1 was elucidated.
  • Waka Nakanishi, Tsutomu Ishikawa, Davor Margetic
    2007 Volume 80 Issue 6 Pages 1187-1193
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    The isomerization process, which is related to racemization of symmetrical 1,2-bis(diaminomethyleneamino)benzenes (=bisguanidinobenzenes) with potential chirality, is caused by bond rotation of aryl–(diaminomethyleneamino) (=aryl–guanidinyl) bond and/or diaminomethylene–imino (=guanidinyl imine) bond. This process was evaluated by temperature-dependent 1H NMR experiments. The guanidinyl imine bond rotation, which is important for the early stage of the inhibition of racemization process, was not restricted by substitution at the ortho-position of the benzene core or alkylation of guanidine function, while protonation of ortho-substituted bisguanidinobenzenes increased the rotation barrier. Changing the guanidine function from cyclic to acyclic caused the rotation about both bonds to become restricted, which could be observed by temperature-dependent 1H NMR experiments.
  • Shingo Yamada, Yasushi Obora, Satoshi Sakaguchi, Yasutaka Ishii
    2007 Volume 80 Issue 6 Pages 1194-1198
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    A new type of carbonylation of styrenes was achieved under a 1:1 mixture of CO (0.5 atm) and O2 (0.5 atm) in the presence of Pd(OAc)2 combined with H5PMo10V2O40·nH2O to give 4-methyl-2-phenylnaphthalen-1(4H)-one in 78% yield. Various substituted styrenes were also carbonylated to the corresponding substituted arylnaphthalen-1(4H)-ones in moderate yields. The reaction was found to proceed in two stages involving the head-to-tail dimerization of styrenes, followed by carbonylation of the resulting dimers. Styrenes were efficiently dimerized under air (1 atm) in the absence of CO even at room temperature to produce head-to-tail dimers in good yields.
  • Avijit Banerji, Debasish Bandyopadhyay, Bidyut Basak, Pizush Kanti Bis ...
    2007 Volume 80 Issue 6 Pages 1199-1201
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    2,2′-Bi(1H-indolyl)-3,3′-dicarbaldehydes, prepared from 1H-indole-3-carbaldehydes by exploiting SET methodology, served as the key compound for synthesizing indolo[2,3-a]carbazoles as well as nitrogen macroheterocycles. Condensation of 2,2′-bi(1H-indolyl)-3,3′-dicarbaldehyde with aliphatic diamines produced Schiff’s base type compounds possessing a 10–14-membered ring.
  • Tomoyuki Tajima, Takahiro Sasamori, Nobuhiro Takeda, Norihiro Tokitoh
    2007 Volume 80 Issue 6 Pages 1202-1204
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    The X-ray crystallographic analysis of a stable stannanethione, Bbt(Titp)Sn=S, reveals that the tin–sulfur bond distance [2.221(3) Å] is ca. 10% shorter than the normal tin–sulfur single bonds and the tin atom of the stannanethione has a trigonal planar geometry, as do as the carbonyl carbon atoms.
  • Ping-Jyun Sung, Yu-Pei Chen, Yu-Mine Su, Tsong-Long Hwang, Wan-Ping Hu ...
    2007 Volume 80 Issue 6 Pages 1205-1207
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    A novel chlorinated briarane derivative, fragilide B (1), was isolated from the Formosan gorgonian coral Junceella fragilis. Fragilide B (1) possesses a s-cis diene moiety in the structure. The structure of 1 was elucidated by interpretation of spectral data and further supported by molecular mechanics calculations.
  • Ryo Sasaki, Hirotaka Sasaki, Seketsu Fukuzawa, Jun Kikuchi, Hiroshi Hi ...
    2007 Volume 80 Issue 6 Pages 1208-1216
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    Morphological phases of DMPC/DHPC mixtures have already been investigated by using SANS, SAXS, NMR, and fluorescence-based techniques, as well as cryo-TEM, in which the manner of temperature is changed stepwise. We continuously monitored temperature-dependent phase transitions of DMPC/DHPC mixtures by DSC. We observed four significant transitions, two of which (transitions 1 and 4) were newly discovered in our current study. It was shown that bicelles have phase transitions similar to vesicles, and we proposed a phase diagram of DMPC/DHPC mixtures based on a continuous temperature change method. Such a phase diagram, in which transition temperatures are shown clearly, has never been reported to our knowledge. Moreover, we studied the doping effect of a synthetic bolaform amphiphile, which is used to construct stable model membranes, and found that the temperature range of the magnetically aligned state shifted to a higher temperature. This result indicates that doping synthetic phospholipids, which is done to create a thermostable membrane, is useful for stabilizing bicelles, worm-like micelles, or perforated lamellae. Such applications might be relevant to a variety of experiments, including those that utilize DMPC/DHPC mixtures as model membranes or alignment media.
  • Toru Matsushita, Yukihide Shiraishi, Shin Horiuchi, Naoki Toshima
    2007 Volume 80 Issue 6 Pages 1217-1225
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    Colloidal dispersions of polymer-protected Pd/Ag/Rh trimetallic nanoparticles were synthesized via self-organization by mixing colloidal dispersions of polymer-protected Rh nanoparticles with those of polymer-protected Pd/Ag bimetallic nanoparticles with a core–shell (Pd-core/Ag-shell) structure, which were prepared in advance by a sacrificial hydrogen-reduction method. The Pd/Ag/Rh trimetallic nanoparticles appeared to have a triple core–shell (Pd-core/Ag-interlayer/Rh-shell) structure on the basis of UV–vis absorption spectra, FT-IR spectra of adsorbed CO, TEM, HR-TEM, and EF-TEM observation. The spontaneously formed trimetallic nanoparticles having an atomic composition of Pd/Ag/Rh = 1/2/13.5 and an average diameter of 2.2 nm showed the highest catalytic activity among the metal nanoparticle catalysts tested here for hydrogenation of methyl acrylate at 30 °C under atmosphere of hydrogen.
  • Sachiko Matsushita, Shigenori Fujikawa, Shinya Onoue, Toyoki Kunitake, ...
    2007 Volume 80 Issue 6 Pages 1226-1228
    Published: June 15, 2007
    Released: June 13, 2007
    JOURNALS RESTRICTED ACCESS
    A smooth TiO2 hollow-spheres array, a kind of inverse opals, was prepared in a wide area (> 1 × 5 cm) in a short time (less than 1 min excluding sintering) using a spin-coating technique. A two-dimensional colloidal crystal was used as a template. The TiO2 sintering process, especially the rate of the temperature increase, was important to copy the periodicity of the colloidal crystal structure. The electron diffraction image taken by the transmission electron microscopy observation showed that the hollow-spheres arrays have anatase-type crystal structure.
feedback
Top