Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 87 , Issue 1
Showing 1-14 articles out of 14 articles from the selected issue
Award Accounts
The Chemical Society of Japan Award for Young Chemists for 2008
  • Yasuhiro Ohki
    2014 Volume 87 Issue 1 Pages 1-19
    Published: January 15, 2014
    Released: January 15, 2014
    [Advance publication] Released: October 12, 2013
    JOURNALS FREE ACCESS
    Biological nitrogen fixation and H2 metabolism are mediated by nitrogenase and hydrogenase, respectively. Their active sites consist of complex transition-metal sulfide/thiolate clusters, which have been long-standing synthetic challenges. This account describes our synthetic approaches toward the active sites of nitrogenase and [NiFe] hydrogenase. A new class of iron–sulfur clusters modeling or structurally analogous to the nitrogenase metallo-clusters, namely P-cluster and FeMo-cofactor, have been synthesized from homogeneous self-assembly reactions of iron(II) amide or mesityl complexes with bulky thiols and elemental sulfur in toluene. A series of thiolate-bridged Fe–Ni complexes modeling the active site of [NiFe] hydrogenase have been synthesized via two ways: One is to use iron(II)–dithiolate complexes carrying CO and CN ligands as precursors to provide the (CO/CN)Fe–Ni complexes. The other way is to split a tetranuclear (CO)3Fe–Ni–Ni–Fe(CO)3 complex, which is available from a sequential reaction of [FeBr2(CO)4] with NaStBu and NiBr2(EtOH)4 at −40 °C.
    Biological nitrogen fixation and H2 metabolism are mediated by nitrogenase and hydrogenase, respectively. Their active sites consist of complex transition-metal sulfide/thiolate clusters, which have been long-standing synthetic challenges. This account describes our synthetic approaches toward the active sites of nitrogenase and [NiFe] hydrogenase. Fullsize Image
     
Accounts
  • Yasuaki Okamoto
    2014 Volume 87 Issue 1 Pages 20-58
    Published: January 15, 2014
    Released: January 15, 2014
    [Advance publication] Released: September 21, 2013
    JOURNALS FREE ACCESS
    Hydrodesulfurization (HDS) catalysts have been extensively used worldwide in refineries to protect the environment. The present Account reviews our recent studies to establish the structure–activity relationships of HDS catalysts on a molecular level. We have developed two molecular approaches to this issue; a molecular cluster approach using intrazeolite Mo sulfide and CoMo binary sulfide clusters possessing well-defined structures and a CVD-CoMo sulfide designed catalyst approach in which Co is exclusively accommodated in the CoMoS structure, the active sites of HDS catalysts. It is revealed that the Co sites of intrazeolite thiocubane-type [Co2Mo2S6] clusters play a pivotal role in HDS reaction and that the Mo–Mo atomic distance of Mo2S4 dinuclear clusters determines the HDS activity. Designed CVD-CoMo catalysts supported on refractory oxides have been successfully prepared by CVD using [Co(CO)3NO] as a precursor of Co. Combined with magnetic properties and XAFS, it is concluded that the CoMoS structure is dinuclear Co sulfide clusters located on the edge of MoS2 nanoparticles. It is shown that the intrinsic activity of the CoMoS structure substantially depends on the MoS2-edge where it is located. The effects of support and additives are discussed on the basis of the intrinsic activity. Both MoS2–support interactions and reaction or sulfidation conditions elucidate the local structure and intrinsic activity of the CoMoS structure. It is demonstrated that the CVD technique using [Co(CO)3NO] provides unique characterization methods of HDS catalysts.
    Novel preparation and catalysis of intrazeolite Mo2S4 and Co2Mo2S6 clusters with well-defined structures and of refractory oxide-supported, fully promoted Co–MoS2 nanoparticles to establish the structure–activity relationships of CoMo HDS catalysts on a molecular level. Fullsize Image
     
BCSJ Award Article
  • Andrea Renzetti, Nobuaki Koga, Hiroshi Nakazawa
    2014 Volume 87 Issue 1 Pages 59-68
    Published: January 15, 2014
    Released: January 15, 2014
    [Advance publication] Released: October 19, 2013
    JOURNALS FREE ACCESS
    The reaction of silyl cyanide (R3SiCN) with hydrosilane (R′3SiH) in the presence of a catalytic amount of [(η5-C5H5)Fe(CO)2Me] formed R′3SiCN and R3SiH. This reaction involves Si–CN bond cleavage and provides a new method for the preparation of silyl cyanides. DFT calculation showed that coordinatively unsaturated [(η5-C5H5)Fe(CO)(SiMe3)] reacts exothermically with Me3SiCN to give the CN π-coordinated complex, [(η5-C5H5)Fe(CO)(η2-Me3SiCN)(SiMe3)], followed by exothermic silyl migration from the iron to the nitrogen atom of the η2-coordinated Me3SiCN with the activation energy of 8.8 kcal mol−1 to give [(η5-C5H5)Fe(CO)(Me3SiC=NSiMe3CN)]. The complex is one of the intermediates in the catalytic cycle. The related complex [(η5-C5Me5)Fe(CO)(κ-C,N-t-BuMe2SiC=NSiPh3)] was isolated in the reaction of [(η5-C5Me5)Fe(CO)(py)(SiPh3)] with t-BuMe2SiCN and characterized by 1H, 13C, and 29Si NMR spectroscopy. The activation energy of the Si–CN bond cleavage in [(η5-C5H5)Fe(CO)(κ-C,N-Me3SiC=NSiMe3)] was evaluated by DFT calculation to be 33.7 kcal mol−1 which is comparable to that in the reaction of acetonitrile (32.9 kcal mol−1).
    The reaction of R3SiCN with R′3SiH is catalyzed by [(η5-C5H5)Fe(CO)2Me] to form R′3SiCN and R3SiH, exhibiting selective Si–CN bond cleavage and a new method for the preparation of silyl cyanides. The reaction mechanism is proposed with the help of DFT calculations. Fullsize Image
     
 
  • Shigenobu Hayashi, Keiko Jimura, Natsuko Kojima
    2014 Volume 87 Issue 1 Pages 69-75
    Published: January 15, 2014
    Released: January 15, 2014
    [Advance publication] Released: October 26, 2013
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    The adsorption state of trimethylphosphine oxide (TMPO) on siliceous MFI-type zeolite, silicalite, has been studied by solid-state NMR. TMPO was loaded by vapor as well as the solvent methods, and 31P and 1H magic-angle-spinning (MAS) NMR spectra were measured. Most of the 31P signals are located at lower frequency than that of crystalline TMPO, among which the 30-ppm signal is the largest. This is the first case of which the signal at about 30 ppm is dominant. The observation of the 30-ppm signal is independent of the TMPO introduction method, vapor or solvent. The dominant signal at about 30 ppm in the sample prepared by vapor shifts to about 37 ppm for ten months, being accompanied by increase in the spinning sideband intensities. This fact indicates that TMPO molecules move to a more stable site with a smaller space, resulting in suppression of the molecular motion. The temperature increase leads to increase in the fraction of mobile TMPO molecules giving a 31P signal at 33.0 ppm. Comparison with the results of silica nanoparticle and mesoporous silica leads to the conclusion that the signals in the frequency range lower than crystalline TMPO are attributed to TMPO molecules confined in the micropores of the MFI-type framework and not interacting with Brønsted acid sites.
  • Chien-Chih Chen, Tomoaki Hinoue, Jui-Hsiang Liu, Ichiro Hisaki, Mikiji ...
    2014 Volume 87 Issue 1 Pages 76-87
    Published: January 15, 2014
    Released: January 15, 2014
    [Advance publication] Released: October 31, 2013
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    Stimuli-responsive luminescent materials in solid state have many useful applications such as optical recording. However, reversible solid–solid phase transitions are not easy due to the restricted movements of molecules. In order to modulate solid-state emission properties via external stimuli, we aimed to induce various crystallization processes from the liquid-crystalline states of trans-alkoxy-nitrostilbene dyes. The structure–property relationships in the crystalline and liquid-crystalline states of the nitrostilbenes were studied by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), powder X-ray diffraction (PXRD), single-crystal X-ray diffraction (SCD), and photoluminescence spectroscopy (PL). Three types of slipped-stacking structures, which display distinct luminescent intensities, were found in their crystalline state. The photoluminescence color of these dyes in the crystalline state changes from green to yellow depending on the length of their substituted alkyl chains. Various external stimuli, including heat, mechanical force, and ultrasound, were applied to the liquid-crystalline state at supercooled temperatures to trigger different crystallization processes. Accordingly, a number of polymorphs were obtained that displayed various luminescent properties. Among these solids, enhanced luminescence of trans-4-undecyloxy-4′-nitrostilbene (NS11) was obtained through packing changes caused by mechanical force and ultrasonication. The reversible fluorescent properties can be applied to fluorescent recording and sensing.
  • Akiharu Satake, Kazuo Tanaka, Hiroki Asakura, Masahiro Okano, Tsutsumu ...
    2014 Volume 87 Issue 1 Pages 88-97
    Published: January 15, 2014
    Released: January 15, 2014
    [Advance publication] Released: October 31, 2013
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    Bis(crown ether)-2,2′-bibenzimidazole 1 and its 1-substituted derivatives were synthesized as new self-assembled motifs. UV–vis and 1H NMR titration experiments of 1 with potassium ions in a mixture of chloroform and methanol (1:1) were carried out. The stoichiometries and curve fitting analysis showed that a 2:2 complex of 1 with potassium ions was formed in a face-to-face fashion. 1-Monosubstituted bis(crown ether)-2,2′-bibenzimidazole 6a having a (dodecylaminocarbonyl)methyl group also gave a 2:2 complex with potassium ions. Structural analysis of the 2:2 complex of 6a with potassium ions was performed using various two-dimensional NMR techniques. Results suggested that, of eight or more possible conformational isomers, the one having the two substituent groups diagonally opposite each other was predominantly formed. Reversible association and dissociation of the 2:2 complex was observed after adding potassium ions and then removing them with an 18-crown-6-ether.
  • Masashi Hojo, Yusuke Kondo, Kosuke Zei, Kei Okamura, Zhidong Chen, Mas ...
    2014 Volume 87 Issue 1 Pages 98-109
    Published: January 15, 2014
    Released: January 15, 2014
    [Advance publication] Released: October 12, 2013
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    Conductometric titrations with triethylamine (Et3N) of mono-, di-, and trisulfonic acids have been performed in acetonitrile, and strong homoconjugation (homoassociation) for di- and trisulfonic acids have been revealed. The appearance of a maximum in the conductometric titration curve enables us to predict the stable homoconjugation species in the solution. The homoconjugation reaction of monosulfonic acids, such as methanesulfonic and p-toluenesulfonic acids, are not large enough to give a maximum. However, disulfonic acids, 1,5, 2,6-, and 2,7-naphthalenedisulfonic acids, give maxima at the first equivalence point, which indicates that the conjugate ions (HA) cause homoconjugation reactions. By means of UV–visible spectroscopy, the stability constant (KD) of dimerization or homoconjugation reaction between two anions [2 HA (HA)2] of the hydrogen 1,5-naphthalenedisulfonate (HA) has been given to be log KD = 4.11 in acetonitrile. In the same solvent, 1,3,6-naphthalenetrisulfonic acid forms more stable species of not only (H2A)2 but also (H2A)(HA2−). Double hydrogen-bonds can operate between two H2A anions in the (H2A)2 species, while even triple hydrogen-bonds in the (H2A)(HA2−) species. Effects of second solvents, including H2O, have been examined in detail on the homoconjugation reactions. In order to differentiate the role of acidities of acids on homoconjugation, the conductometric titrations of nitrobenzenedicarboxylic acids have been also performed. The geometries of homoconjugated sulfonic acids have been justified by DFT calculations.
  • Yuki Kushida, Osamu Shirai, Yuki Kitazumi, Kenji Kano
    2014 Volume 87 Issue 1 Pages 110-112
    Published: January 15, 2014
    Released: January 15, 2014
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    The propagation of the change in membrane potential between two aqueous phases across two parallel membranes from the sending site to the receiving site was elucidated. The potential differences at every interface are controlled by the ion transfers and the circulating current flowed to keep the electroneutrality of every phase.
  • Masaki Ohtawa, Hiroshi Tomoda, Tohru Nagamitsu
    2014 Volume 87 Issue 1 Pages 113-118
    Published: January 15, 2014
    Released: January 15, 2014
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    Here we report a novel and efficient method for the regioselective mono-deprotection of di-tert-butylsilylene acetals derived from 1,3-diols consisting of primary and secondary alcohols. The ammonium fluoride-mediated reactions of pyripyropene A derivative, thymidine and uridine derivatives, methyl β-D-glucofuranoside, and pyranoside derivatives each gave the corresponding primary alcohol with high regioselectivity.
  • Kohei Tagawa, Keita Sasagawa, Ken Wakisaka, Shunsuke Monjiyama, Mika K ...
    2014 Volume 87 Issue 1 Pages 119-126
    Published: January 15, 2014
    Released: January 15, 2014
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    The reaction of PhCOCH2Br and NaOMe in MeOH gave PhCOCH2OH as the major product and PhCOCH2OMe as the minor product. Substituent effects on the reactivity and product selectivity revealed that an electron-withdrawing substituent on the phenyl ring enhanced the overall reactivity and gave more alcohol than ether. It was indicated that the alcohol was formed via carbonyl addition-epoxidation, whereas the ether was formed by direct substitution. Substituent effects on the reaction rates, as well as the effects of NaOMe concentration on the rate and product ratio for both reactions of PhCOCH2Br and PhCOCH2Cl are in line with the mechanism that the alcohol and ether products were formed via two independent and concurrent routes, carbonyl addition and α-carbon attack, respectively, and thus the reaction mechanism could be different from the bifurcation mechanism previously predicted for the reaction of PhCOCH2Br by a simulation study in the gas phase.
  • Souichirou Kawazoe, Yoshinori Okamoto, Masaki Yokota, Hirokazu Kubota, ...
    2014 Volume 87 Issue 1 Pages 127-140
    Published: January 15, 2014
    Released: January 15, 2014
    [Advance publication] Released: October 31, 2013
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    Both (+)- and (−)-4-{[(2-{4-chlorophenylsulfonylamino}-1-{3-[(E)-2-(7-chloro-2-quinolyl)-vinyl]phenyl}ethyl)thio]methyl}benzoic acid (1), Thromboxane A2 and Leukotriene D4 receptor dual antagonist were synthesized. Racemic methyl 4-({[2-amino-1-(3-hydroxymethylphenyl)ethyl]thio}methyl)benzoate (2), and methyl 4-[({2-amino-1-[3-(1,3-dioxolan-2-yl)phenyl]ethyl}thio)methyl]benzoate (3) were derived from 2-(3-bromophenyl)-1,3-dioxolane (4). Compound 2 was resolved via di-p-toluoyl-D/L-tartaric acid salts to transform to (+)- and (−)-1, respectively. We also demonstrated that one optically active salt of compound 2 was converted to optically active (+)-1 without chromatography purification.
  • Taku Shoji, Akifumi Maruyama, Mitsuhisa Maruyama, Shunji Ito, Tetsuo O ...
    2014 Volume 87 Issue 1 Pages 141-154
    Published: January 15, 2014
    Released: January 15, 2014
    [Advance publication] Released: November 08, 2013
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    6-Methoxy- and 6-dimethylaminoazulenes with methylthio groups at the 1- or 1,3-positions have been prepared by electrophilic substitution of the corresponding azulenes with DMSO in the presence of acid anhydride, followed by treatment with Et3N. The products, 1-methylthioazulenes, reacted with Tf2O to afford the corresponding 1,1′-biazulene derivatives in moderate yields. The redox behavior of these azulene and 1,1′-biazulene derivatives was examined by cyclic voltammetry (CV), which revealed reversible electron transfers under electrochemical oxidation conditions. 6-Dimethylamino-1,3-bis(methylthio)azulenes with a heteroaryl group at the 2-position were also prepared by the reaction of 6-dimethylamino-1,3-bis(methylthio)azulene with triflates of N-containing heterocycles, i.e., pyridine, quinoline, isoquinoline, acridine, and 1,10-phenanthroline, followed by treatment with KOH in alcohols.
  • Takuhiro Ishii, Tomonobu Mizumo, Yoshiro Kaneko
    2014 Volume 87 Issue 1 Pages 155-159
    Published: January 15, 2014
    Released: January 15, 2014
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    An ionic liquid containing silsesquioxane framework (SQ-IL) was successfully prepared by the hydrolytic condensation of trimethyl[3-(triethoxysilyl)propyl]ammonium chloride in aqueous solution of bis(trifluoromethanesulfonyl)imide (TFSI). The energy-dispersive X-ray analysis of SQ-IL indicated that the molar ratio of quaternary ammonium cation to TFSI anion in SQ-IL was ca. 1:1. The 29Si NMR spectrum of SQ-IL showed two broad peaks in T2 and T3 regions. The weight-average molecular weight estimated by static light-scattering measurement was ca. 1.8 × 103. In addition, the X-ray diffraction pattern of SQ-IL did not show any diffraction peaks. On the basis of these results, it was concluded that SQ-IL was an amorphous oligomeric silsesquioxane compound containing equimolar quaternary ammonium cations and TFSI anions. The differential scanning calorimetry thermogram of SQ-IL exhibited an endotherm peak due to glass transition at 15 °C, and SQ-IL showed fluidity over ca. 35 °C, indicating that SQ-IL was fluid below 100 °C (i.e., an ionic liquid). In the thermogravimetric analyses, the temperatures of thermal decomposition of SQ-IL were higher than those of N,N,N-trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide, which is an ionic liquid compound with the same structure as that of the side chains of SQ-IL. This result indicated that the silsesquioxane framework could suppress thermal degradation.
  • Koutaro Honda, Yusuke Ide, Nao Tsunoji, Masato Torii, Masahiro Sadakan ...
    2014 Volume 87 Issue 1 Pages 160-166
    Published: January 15, 2014
    Released: January 15, 2014
    [Advance publication] Released: October 26, 2013
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    An alternative and efficient way to synthesize HUS-1 (Hiroshima University Silicate-1, Si10O24H8·2[(CH3)4N]), and a new notable function of HUS-1 are reported. HUS-1, which is an ast-type layered silicate, was originally synthesized through a complicated process from two kinds of dealuminated zeolites, FAU and *BEA, with tetramethylammonium (TMA) and benzyltrimethylammonium hydroxides, respectively. In this article, the synthesis of HUS-1 by using only amorphous silica and TMA as a silica source and a structure directing reagent, respectively, with varied temperature, time, and composition of a starting mixture containing water, TMA hydroxide, sodium hydroxide, and amorphous silica, in the presence or the absence of a seed crystal was examined to find that HUS-1 successfully formed for a wide range of NaOH/SiO2 (0.2–0.6) and TMA/SiO2 (0.2–0.8) ratios and reaction time (3–21 days) at a H2O/SiO2 ratio of 5.5 and reaction temperature of 140 °C in the presence and the absence of a seed crystal. The particle size and crystallinity of HUS-1 varied depending on the synthetic conditions. The obtained HUS-1 selectively adsorbed Ni2+ from a mixed electrolytes solution mimicking seawater. The maximum amount of the adsorbed Ni2+ on HUS-1 was dependent on the synthetic conditions.
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