Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 63 , Issue 10
Showing 1-50 articles out of 64 articles from the selected issue
  • Osamu Kikuchi, Hui Wang
    1990 Volume 63 Issue 10 Pages 2751-2754
    Published: 1990
    Released: June 05, 2006
    JOURNALS FREE ACCESS
    The parity-violating energy shift, Epv, was calculated for glycine, alanine, and serine using the HFO-5G and -6G minimal basis sets, which were determined so as to well reproduce the behavior of an atomic orbital near the nucleus. A clear basis set dependence was observed in both the sign and magnitude of Epv. For the zwitterionic form of glycine, the HFO-5G and -6G calculations gave an Epv similar to that obtained by the (14,14/10) minimal basis set. For the most stable conformation of L-alanine, these basis set gave a negative Epv, indicating that L-alanine is more stable than D-alanine, while the split-valence basis sets gave positive values. It was shown that L-serine is lower in energy than D-serine due to the parity-violating interaction for almost the entire range of the C–C rotation angle.
  • Ichiro Tanahashi, Akihiko Yoshida, Atsushi Nishino
    1990 Volume 63 Issue 10 Pages 2755-2758
    Published: 1990
    Released: June 05, 2006
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    Two types of activated carbon tablets (AC tablets) were prepared and characterized by adsorption methods for electric double-layer capacitors. The tablets were prepared from either the activation or carbonization of molded mixtures comprising phenolic resin-based activated carbon powders and phenolic resins. The specific surface area of the tablets (a) prepared from activation was 2010 m2g−1 and the bulk density was 0.45 gcm−3. The area of tablets (b) from carbonization was 1400 m2g−1 with a yield of 83% (weight of obtained tablets/weight of molded mixtures). The capacitance of the capacitors with tablets (a) showed 7.3–12.5 F/(cm3 of AC tablets). The reliability of the capacitors with AC tablets (a) and (b) was improved in comparison with that of capacitors with polarizable electrodes comprising activated carbon powders and binders.
  • Shinsaku Fujita
    1990 Volume 63 Issue 10 Pages 2759-2769
    Published: 1990
    Released: June 05, 2006
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    Subduction of the coset representations of Ih point group produces tables of unit subduced cycle indices (USCIs) with and without chirality fittingness (CF). These indices are applied to the enumeration of dodecahedrane derivatives with respect to their molecular formulas as well as to their symmetries. The USCIs are effective to the enumeration of such derivatives as having only achiral substituents on the vertices of a dodecahedrane skeleton. On the other hand, the USCI–CFs are used for enumerating dodecahedrane derivatives with achiral and chiral substituents. Substitutions on the edges of the dodecahedrane skeleton are also discussed in terms of the present USCI approach.
  • Shinsaku Fujita
    1990 Volume 63 Issue 10 Pages 2770-2775
    Published: 1990
    Released: June 05, 2006
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    A combination of the concept of unit subduced cycle indices (USCIs) and the Redfield–Read superposition theorem affords a new methodology of enumerating geometrical objects such as molecules and polyhedra. This method allows us to enumerate such objects with respect not only to their constitutions but also to their symmetries, in which subduced cycle indices (SCIs) derived from USCIs play an important role. Further derivation of a cycle index from the SCIs and its incorpotation with the superposition theorem are also discussed. The inverse of the mark table and the table of USCIs for D2d point group are presented for further applications of the USCI approach.
  • Seishiro Fukutani, Keizo Sakaguchi, Hiroshi Jinno
    1990 Volume 63 Issue 10 Pages 2776-2780
    Published: 1990
    Released: June 05, 2006
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    Analysis of a reaction mechanism by assembling the scheme with elementary reactions requires numerical solution of the reaction rate equations. The numerical procedure is time-consuming because of the stiffness of rate equations particularly when temperature varies with the reaction progress. This investigation proposed an approximation method which can save computational time for solving reaction rate equations in a homogeneous reaction field. The approximation method reduces the rate equations, which are a set of simultaneous differential equations, to independent differential equations for each species by simplifying the original equations according to the reaction characteristics; the resultant differential equations can be solved analytically within small time intervals. The validity of these differential equations was verified by comparing the obtained changes in temperature and the species concentrations in hydrogen combustion with those calculated from the original equations with the Runge–Kutta–Gill method.
  • Jun-ichi Aihara
    1990 Volume 63 Issue 10 Pages 2781-2784
    Published: 1990
    Released: June 05, 2006
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    Duley and Jones recently proposed that small linear polyacenes (e.g., anthracene) were responsible for the IR emission observed in localized regions of some UV-excited nebulae. Linear polyacenes are relatively stable in the first excited state although they are not very stable in the ground state. This probably is the primary reason why this type of benzenoid hydrocarbons are observed in the interstellar medium.
  • Hidekazu Doe, Hiroshi Ohe, Hiroyuki Matoba, Akio Ichimura, Toyokichi K ...
    1990 Volume 63 Issue 10 Pages 2785-2789
    Published: 1990
    Released: June 05, 2006
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    The ion-association constants, K1A, of an ion pair, M2+ClO4 (M=Ca, Sr, Ba), have been determined by conductometric measurements in methanol–ethylene glycol mixtures of 0, 20, 40, 60, 80, and 100 wt% of ethylene glycol at 5, 15, 25, 35, and 45 °C. The conductometric data were treated by an improved Fuoss and Edelson method. The thermodynamic functions of ΔH1A\ominus and ΔS1A\ominus have also been determined at 25 °C from the temperature dependence of K1A. In 60–80 wt% of ethylene glycol the K1A values of these metal perchlorates are similar to each other, since the characteristics of individual metal ions are probably depressed by the strong solvations of those cations. The results are discussed while considering the cation solvation and structure of a bulk solvent.
  • Yasuo Watababe, Masami Nakada, Kazutoyo Endo, Hiromichi Nakahara, Hiro ...
    1990 Volume 63 Issue 10 Pages 2790-2796
    Published: 1990
    Released: June 05, 2006
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    KX-Ray-gated emission Mössbauer spectra and time-resolved emission Mössbauer spectra of 57Co-labelled CoSeO4 and CoSeO4·H2O were measured at room temperature using a coincidence technique. No difference in the area intensity ratio of 57Fe(II) to the sum area intensity of 57Fe(II) and 57Fe(III) was observed for anhydrous CoSeO4 between the KX-ray-gated and non-gated emission spectra; a larger area intensity of 57Fe(II), however, was observed for the KX-ray-gated sectrum of CoSeO4·H2O than for the non-gated one. This difference is attributed to different local radiolytic effect of the deexcitation processes between KX-ray and Auger electron emission. The time-dependence in the area intensity ratio of 57Fe(II) to the sum area intensity of 57Fe(II) and 57Fe(III) was observed for CoSeO4·H2O. The relaxation process observed for CoSeO4·H2O by its time-resolved spectrum indicates that the radicals formed in the EC-decay oxidize 57Fe(II) on the time scale of the nuclear lifetime of the first excited state of 57Fe, and that a radical reaction plays an important role in determining the relaxation time.
  • Hitoshi Watarai, Koh Sasaki, Naoko Sasaki
    1990 Volume 63 Issue 10 Pages 2797-2802
    Published: 1990
    Released: June 05, 2006
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    The role of the interface in ion-association extraction kinetics of iron(II) with 1,10-phenanthroline(phen), 4,7-dimethyl-1,10-phenanthroline(DMP) or 4,7-diphenyl-1,10-phenanthroline(DPP) from sodium salt solutions was investigated by means of a high-speed stirring technique and a stopped-flow method. The initial extraction rates of the ion pairs were proportional to the first order of both iron(II) and the ligand concentrations in all cases studied; it was therefore suggested that the rate-controlling step is the formation of mono-complexes. From analyses using the adsorption constants and the distribution constants of the ligands and the formation-rate constants of the mono-complexes in the aqueous phase it was concluded that the location where the rate-controlling reaction takes place depends on the ligands: a bulk aqueous phase in phen, an interface in DPP, and both of a bulk aqueous phase and an interface in the case of DMP. The extraction rates were apparently reduced by an interfacial adsorption of the ion pairs, which was governed by the hydrophobicity of the ligands and the hydrophilicity of the counter anions.
  • Mutsuo Kodama, Anung Budhi Mahatma, Toru Koike, Eiichi Kimura
    1990 Volume 63 Issue 10 Pages 2803-2808
    Published: 1990
    Released: June 05, 2006
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    Although an attempt to isolate pure crystallines of Ag(II) complexes failed, we could prepare stable aqueous solutions of the Ag(II) complexes of [15]aneN5, [16]aneN5, and their acetic acid derivatives by disproportionation reactions of Ag(I) induced by these polyaza macrocycles, and have investigated their electrochemical redox behaviors using conventional voltammetric methods. All Ag(II) complexes including the [14]aneN4 (cyclam) complex undergo a reversible two-electron reduction at DME (dropping mercury electrode). From the potential where the i2⁄(i1i) ratio is unity, the log formation constants were determined to be 43.4, 43.6, 43.3, 39.3, and 42.5 for the cyclam, [15]aneN5, [16]aneN5, cyclam-tetraacetic acid, and [15]ane5-pentaacetic acid complexes, respectively. Cyclic voltammetric (CV) oxidation scans at the glassy carbon electrode showed a reversible one-electron response (separation of anodic and cathodic peak potentials, ΔEp′=70 mV; the ratio of anodic and cathodic peaks, (ip)c⁄(ip)a′=1), which can be ascribed to a reversible Ag(III)/Ag(II) redox change. Though the acetate groups attached to the nitrogen atoms contribute to the net destabilization of the Ag(II) complexes, they exert a large positive effect on the thermodynamic stability of the Ag(III) state.
  • Shuzo Akiyama, Kenichiro Nakashima, Nanako Shirakawa, Kyoko Yamada
    1990 Volume 63 Issue 10 Pages 2809-2813
    Published: 1990
    Released: June 05, 2006
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    Three types of high-performance liquid chromatographic column packing materials ((3-morpholinopropyl)-, [3-(1-piperazinyl)propyl]-, and (3-piperidinopropyl)silyl silica gels) were newly prepared and examined for their ability to separate water-soluble vitamins. Six vitamins (ascorbic acid, nicotinic acid, thiamine hydrochloride, pyridoxine hydrochloride, hydroxocobalamin acetate, and flavin adenine dinucleotide) in sample solutions could be completely separated within less than 12 min by UV detection on a column packed with morpholinopropylsilyl silica gel by using a phosphate buffer [0.1 M (1 M=1 moldm−3) H3PO4−0.1 M Na2HPO4 (pH 6.0) containing 10 mM tetrabutylammonium bromide] as an eluent. This efficient gel was successfully applied to vitamin analyses of commercially available healthful beverages. The other column packing materials also showed characteristic for specific water-soluble vitamin analysis. Typical separations are presented.
  • Isao Sanemasa, Tomonori Osajima, Toshio Deguchi
    1990 Volume 63 Issue 10 Pages 2814-2819
    Published: 1990
    Released: June 05, 2006
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    The complex formation of cyclodextrin (CyD, host) with C5 to C9 normal alkanes (guests) has been studied in aqueous medium at 25°C by making use of the volatilization rate of alkane molecules from aqueous into gaseous phase. In the excess of the host, β- and γ-CyDs form 1:1 complexes, while α-CyD forms 1:1 and 2:1 (host: guest) complexes. With an increase in the chain length of alkane, association constants for three CyDs increased; in the case of α-CyD, the 1:1 association constant for C9 was identical to that for C8, while the 2:1 association constant continued to increase. The cavity size of CyD, the alkane chain length, and hydrophobicity and surface area of alkane molecules were taken into account to discuss the host-guest inclusion mechanism.
  • Yasuo Tohda, Miyuki Eiraku, Takao Nakagawa, Yumi Usami, Masahiro Ariga ...
    1990 Volume 63 Issue 10 Pages 2820-2827
    Published: 1990
    Released: June 05, 2006
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    The reaction of 1-methyl-3,5-dinitro-2-pyridone (1a) with ketones or aldehydes in the presence of ammonia gave alkyl- and/or aryl-substituted 3-nitropyridines (6) in moderate to high yields. Enamines derived from the ketones gave better results than did the ketones themselves; on the other hand, those derived from the aldehydes gave no 6 at all. On the basis of deuterium-labeled experiments, a mechanism comprising competitive ring transformations of 1a is proposed.
  • Hideki Ishida, Koji Yui, Yoshio Aso, Tetsuo Otsubo, Fumio Ogura
    1990 Volume 63 Issue 10 Pages 2828-2835
    Published: 1990
    Released: June 05, 2006
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    2,5-Bis(dicyanomethylene)-2,5-dihydrofuran with a 2,5-furanoquinonoid skeleton and its extensive conjugated homologues, 5,5′-bis(dicyanomethylene)-5,5′-dihydro-Δ2,2′-bifuran (8a), and 5,5″-bis(dicyanomethylene)-5,5″-dihydro-Δ2,2′:5′,2″-terfuran (12a), have been prepared as a new type of oxygen-containing electron acceptors. In the synthetic course of the tetrabromo derivative of 12a, 3′,4-dibromo-5-(3,5-dibromo-2-furyl)-3,5′-bis(dicyanomethylene)-3,5′-dihydro-Δ2,2′-bifuran was also obtained as an unsymmetrical isomer possessing an unusual 2,3-furanoquinonoid conjugation, whose structure was confirmed on the basis of X-ray crystallographic analysis. In addition, X-ray analysis of the TTF complex of 8a revealed that the bifuranoquinonoid conjugation has a trans form. These furanoquinonoid compounds behaved as weak electron acceptors, and accordingly failed to form conductive complexes. However, the 3,3′-dibromo derivative of 8a gave the TTT complex of a very high electrical conductivity.
  • Yoshiaki Kusuyama, Tamami Kagosaku, Takeshi Hasegawa
    1990 Volume 63 Issue 10 Pages 2836-2842
    Published: 1990
    Released: June 05, 2006
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    Carbon-13 chemical shifts have been measured for the cyclopropyl carbon atoms of twenty one p- substituted (cis- and trans-2-chlorocyclopropyl)benzenes. The substituent induced chemical shifts (SCS) for the trans derivatives are shifted down field by electron-acceptor substituents and upfield by electron-donating substituents (normal SCS). This SCS trend is the same as those observed for the p-substituted cyclopropylbenzenes, while the SCS range is small because of the decreased polarization of C-1–C-2 bonding due to the attached chlorine atom. For the cis derivatives, SCS for C-1 and C-3(CH2) carbons were also normal, while no measurable SCS was observed for C-2(CCl). The SCS well fitted with the LSFE equation, indicating that the SCS were controlled mainly by a polar effect, except for C-2(CCl, cis).
  • Seizi Kozuka, Takemi Nitta
    1990 Volume 63 Issue 10 Pages 2843-2845
    Published: 1990
    Released: June 05, 2006
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    A kinetic study has been conducted on the reactions of (arylthio)trimethylgermanes with various haloalkanes. Bimolecular nucleophilic attack of the sulfur atom has been found as the mechanisms for the reactions with normal haloalkanes while the mechanism was found to deviate from bimolecular attack to unimolecular ionization of the haloalkane, dependent on the structure of the alkyl groups with increasing of the steric hindrance. Reaction of a secondary haloalkane also proceeded by unimolecular ionization.
  • Toshiyuki Oshiki, Tsuneo Imamoto
    1990 Volume 63 Issue 10 Pages 2846-2849
    Published: 1990
    Released: June 05, 2006
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    Functionalizations of the boranato group of phosphine–boranes have been investigated. Trimethylphosphine–borane readily reacted with methanesulfonic acid in dichloromethane with evolution of hydrogen. The resulting trimethylphosphine–methylsulfonyloxyborane was subjected to nucleophilic substitution reaction on the boron atom with arenethiols or secondary phosphine–boranes in the presence of NaH. The reactivities of the substitution products obtained were also investigated. A new phosphine–borane having a P–B–P–B–P–B–P–B bond linkage was synthesized.
  • Suketaka Ito, Akikazu Kakehi
    1990 Volume 63 Issue 10 Pages 2850-2856
    Published: 1990
    Released: June 05, 2006
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    Configuration alteration and hybridization change in the addition of hydrogen bromide to ethylene and those in its reverse, E2-type reaction were illustrated in terms of orbital tilting on the basis of the concept of stabilizing and destabilizing second order orbital interactions. The predominancy of trans fashion in these reactions are also visualized qualitatively.
  • Shuji Kanemasa, Hidetoshi Yamamoto, Eiji Wada, Tosio Sakurai, Kunio Ur ...
    1990 Volume 63 Issue 10 Pages 2857-2865
    Published: 1990
    Released: June 05, 2006
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    α,β-Unsaturated esters bearing a chiral oxazolidine or perhydropyrrolo[1,2-c]imidazole auxiliary at the β-position have been prepared and applied to the cycloadditions with N-metalated azomethine ylides derived from α-(benzylideneamino) esters. These reactions are found to proceed with an exclusively high diastereofacial selectivity to give 2,4-pyrrolidinedicarboxylates with four consecutive chiral centers after the removal of chiral auxiliary. Detailed stereochemistry in the transition state is discussed.
  • Shuji Kanemasa, Kenji Doi, Eiji Wada
    1990 Volume 63 Issue 10 Pages 2866-2871
    Published: 1990
    Released: June 05, 2006
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    Intramolecular cycloadditions of the azomethine ylides bearing a carbonyl-activated olefinic moiety, generated from α-amino acids or esters and 5-oxo-6-heptenals or 4-oxo-5-hexenals, produce the stereoselective internal cycloadducts either to olefin or carbonyl dipolarophilic function with normal or inverse regioselectivity, depending upon the types of ylides as well as the intervening chain length. Exclusively high diastereofacial selectivity has been achieved when 2-phenyl-4-thiazolidinecarboxylic acid and its methyl ester are utilized.
  • Wataru Agui, Masahito Takeuchi, Masahiko Abe, Keizo Ogino
    1990 Volume 63 Issue 10 Pages 2872-2876
    Published: 1990
    Released: June 05, 2006
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    A study was made concerning the removal of leachables released from mixed-bed ion exchange resins. The key concerns were to determine the optimum mixed ratio of strong acid cation exchange resins (SACERs) and strong base anion exchange resins (SBAERs), which give the minimum value of total organic carbon (TOC) released from the resin mixtures and to investigate the effect of synthetic carbonaceous adsorbents on the adsorption of the leachables. The leaching rates of the leachables from the resin mixtures were dependent on the mixed ratios of SACERs and SBAERs. The TOC value for the leachables showed a minimum for a SACER-to-SBAER volume ratio of 9:1, far different from the mixed ratio in ordinary water treatment. The release of leachables from resin mixtures was mainly due to SBAER. The carbonaceous adsorbent having a higher hydrophobic surface adsorbed the leachables well from the resin mixtures.
  • Tooru Hasebe
    1990 Volume 63 Issue 10 Pages 2877-2880
    Published: 1990
    Released: June 05, 2006
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    1H NMR line shapes and their second moments for t-butyl compounds {(CH3)3CX where X=Br, Cl, and NO2} have been studied as a function of temperature. It is shown that the methyl group and the t-butyl group uniaxial reorientations are distinguished by 1H NMR technique. The dipolar interactions modulated by these motions are reported in three cases: the first where methyl reorientation is fast while t-butyl reorientation is slow, the second where t-butyl reorientation is faster than methyl reorientation, and the third where both reorientations are in almost the same rate. The results obtained here are consistent with the results of 1H NMR relaxation studies reported previously.
  • Hiroaki Okamoto, Tatsuo Arai, Hirochika Sakuragi, Katsumi Tokumaru
    1990 Volume 63 Issue 10 Pages 2881-2890
    Published: 1990
    Released: June 05, 2006
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    Among 1-pyrenylethylenes with an alkyl (t-butyl) or an aryl (phenyl) group on the β ethylenic carbon, 1-(3,3-dimethyl-1-butenyl)pyrene (BP) undergoes cis-to-trans one-way isomerization on benzil sensitization, whereas 1-styrylpyrene (SP) undergoes mutual isomerization between the cis and trans isomers to afford an extremely high photostationary state composition (98%) of the trans isomer. Transient spectroscopy and measurements of the isomerization quantum yields revealed that the trans triplet state is the most stable and populated conformation on the triplet energy surface for both BP and SP; however, a higher degree of stabilization of the trans conformation for BP than for SP compared to the perpendicularly twisted conformation makes BP and SP one-way and two-way isomerizing, respectively.
  • Yoshihiro Ikari, Hironobu Sakamoto, Sekiichiro Nakama, Yoshinori Nibu, ...
    1990 Volume 63 Issue 10 Pages 2891-2898
    Published: 1990
    Released: June 05, 2006
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    Assignment of the normal vibrations of 5-chloro-, 5-bromo-, 5-methyl-, and 2-methylpyrimidines was made through the vibrational analyses of the polarized Raman and infrared spectra and also through the normal coordinate calculation. The normal vibrations of 5-halo- and 5-methylpyrimidines were compared with those of 2-halo- and 2-methylpyrimidines, and a substitutional effect on the vibrational frequencies and modes of the hydrogen bending and wagging vibrations was studied.
  • Jun-ichi Aihara
    1990 Volume 63 Issue 10 Pages 2899-2903
    Published: 1990
    Released: June 05, 2006
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    Naturally occurring heterocycles such as imidazole and thiophene do not conform to the rule of topological charge stabilization. Abiotic synthesis and biosynthesis of such heteroconjugated molecules can be rationalized in terms of aromatic stabilization. Antiaromatic molecules are formed neither in primitive-Earth-simulation experiments nor in living systems.
  • Kim Simonsen, Masatoshi Hamada, Nahomi Suzuki, Masaaki Kojima, Shigeru ...
    1990 Volume 63 Issue 10 Pages 2904-2910
    Published: 1990
    Released: June 05, 2006
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    The cis- and trans- [RhCl2(dmap)2]+ (dmap=1,3-bis(dimethylarsino)propane) complexes were prepared by reaction of RhCl3·3H2O with dmap, and the molecular structures of these complexes were determined by the single crystal X-ray diffraction method. Crystal data and final R values are: trans-[RhCl2(dmap)2]ClO4 (1), monoclinic, Cc, a=20.018(4), b=10.229(1), c=12.972(2) Å, β=99.98(2)°, V=2616(1) Å3, Z=4, R=0.034 for 1298 observed unique reflections. cis-[RhCl2(dmap)2]PF6 (2a), orthorhombic, Pca21, a=14.699(2), b=9.381(2), c=19.640(9) Å, V=2704(1) Å3, Z=4, R=0.086 for 1284 reflections. cis-[RhCl2(dmap)2]CF3SO3 (2b), orthorhombic, Pca21, a=14.700(3), b=9.381(4), c=19.644(8) Å, V=2709(2) Å3, Z=4, R=0.088 for 1094 reflections. The Rh–As distances in the linear As–Rh–As groups are 2.442(4)–2.454(4) Å (av 2.446(4) Å) for (1), 2.345(4) and 2.484(6) (av 2.415(6) Å) for (2a), and 2.389(10) and 2.441(10) Å (av 2.415(10) Å) for (2b), while those in the linear As–Rh–Cl groups are 2.385(3) and 2.370(4) Å (av 2.378(4) Å) for (2a), and 2.387(4) and 2.367(5) Å (av 2.377(5) Å) for (2b). The molecular structure of trans-[CoCl2(dmap)2]Clo4 (3) was also determined by the X-ray method. Crystal data and the final R value are: orthorhombic, Pccm, a=8.018(2), b=8.428(1), c=18.716(3) Å, V=1265 Å3, Z=2, R=0.095 for 1072 reflections. A series of trans-[RhX2(dmap)2]+ (X=Cl, Br, I) were prepared and their absorption spectra were compared with one another and with those of related complexes.
  • Shunzo Yamamoto, Akihide Kanetsuki, Yoshimi Sueishi, Norio Nishimura
    1990 Volume 63 Issue 10 Pages 2911-2915
    Published: 1990
    Released: June 05, 2006
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    The mercury-photosensitized decompositions of 2-azetidinone(AZ) and 4,4-dimethyl-2-azetidinone(DMAZ) have been studied at 453 and 423 K and at pressures from 750 to 18000 Pa and from 640 to 5000 Pa, respectively. The major products from AZ were carbon monoxide and ethylene, while ammonia was a minor product. The yields of carbon monoxide and ethylene increased linearly with increasing reaction time and light intensity; they were independent of the AZ pressure. These results suggest that carbon monoxide and ethylene are the primary products. The major products from DMAZ were carbon monoxide, isobutene, and 2,2-dimethylaziridine; ethane, isobutane, and propylene were the minor products. The yields of carbon monoxide, isobutene, and dimethylaziridine increased linearly with increasing reaction time and light intensity at 3800 Pa, showing that these products are the primary ones. The formation of minor products was not linear with time. The quantum yields of carbon monoxide and isobutene were independent of the DMAZ pressure, while the relative yield of dimethylaziridine to that of carbon monoxide increased and those of the minor products decreased with an increase in pressure. Plausible mechanisms were proposed.
  • Haruo Watanabe, Jun’etsu Seto
    1990 Volume 63 Issue 10 Pages 2916-2921
    Published: 1990
    Released: June 05, 2006
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    The intrinsic equilibrium constants of the surface hydroxyl groups, which describe the ionization of surface hydroxyl groups and the complexation of ions of a KCl electrolyte, were calculated with the surface charge densities determined by the potentiometric titration, and with the surface site densities evaluated by the surface hydroxyl group densities. The values of the intrinsic ionization constants, Kalint and Ka2int of maghemite, are higher than those of hematite, and the differences of these values have a tendency for ΔpKalint<ΔpKa2int The values of the intrinsic complexation constants, *KK+int and *KCl-int, of maghemite are higher than those of hematite. These results could be attributed to the differences of the electron densities of the oxygen atoms of the surface hydroxyl groups, which are linked to those in the bulk those of maghemite are lower than those of hematite. Also, the differences become smaller with increasing number of bonding protons.
  • Ichiro Okura, Yuichi Kinumi
    1990 Volume 63 Issue 10 Pages 2922-2927
    Published: 1990
    Released: June 05, 2006
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    Viologen-linked water-soluble zinc porphyrins with different methylene chain lengths between porphyrin and viologen, Zn-PC3(CnV) (n=2–6), were both synthesized and characterized. The lifetimes of the photoexcited triplet states of these compounds were almost the same as those of zinc porphyrins without linked viologen. The fluorescence decay profiles, however, comprised two components with first-order decay (shorter and longer lifetimes) indicating the existence of two conformations: complexed and extended conformers. In the complexed conformer, photoexcited singlet state is quenched by linked viologen. These compounds were applied to photoinduced hydrogen evolution in a system containing NADPH, Zn-PC3(CnV), and hydrogenase under steady state irradiation. Upon irradiation of the sample solution hydrogen was generated, indicating that all of the compounds, Zn-PC3(CnV) (n=2–6), can be substrates of the enzyme hydrogenase, and that every compound participates as both a photosensitizer and an electron carrier in the same molecule.
  • Jun Yamauchi, Hideo Fujita
    1990 Volume 63 Issue 10 Pages 2928-2932
    Published: 1990
    Released: June 05, 2006
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    One of the Wurster’s blue cation radicals, which is composed of the N,N,N′,N′-tetramethyl-p-phenylenediamine cation and iodine anion moieties, was prepared and its magnetic susceptibility measured from 2.6 to 300 K. The cation radical underwent no phase transition within this temperature range in striking contrast with the first-order phase transition observed in perchlorate and tetrafluoroborate salts, regardless of similar crystallographic structures. In addition, the temperature dependence of the magnetic susceptibility could be well-reproduced by a dimer model: a thermally accessible triplet state lying above a singlet ground state with an energy separation of ΔEk=229 K. This behavior is controversial regarding the crystallographic determination. The unusual magnetic properties of the iodide salt were discussed, together with the crystal structure, ESR and visible absorption data, in comparison with those of the other salts.
  • Katsumi Yonemoto, Isao Shibuya, Tohru Tsuchiya, Masahiko Yasumoto, Yoi ...
    1990 Volume 63 Issue 10 Pages 2933-2937
    Published: 1990
    Released: June 05, 2006
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    S-Thioaroylsulfenamides (ArCSSNH2), formed by reaction of ArCSSNa+ with hydroxylamine-O-sulfonic acid, were aroylated or acylated to give N-aroyl- or N-acyl-S-thioaroylsulfenamides, respectively, which were then cyclized with dehydration to afford 3-substituted 5-aryl-1,4,2-dithiazolium salts. The behavior of 3,5-diphenyl-1,4,2-dithiazolium perchlorate toward nucleophiles such as active methylene and amino compounds was studied systematically. The reaction can be classified into two cases depending on fission modes of initial adducts, i.e., ring opening–ring closure reaction (Path B) and fragmentation of dithiazole ring (Path C), and in some cases the initial adducts were isolated.
  • Michihiko Noguchi, Yasutoshi Kiriki, Takashi Ushijima, Shoji Kajigaesh ...
    1990 Volume 63 Issue 10 Pages 2938-2944
    Published: 1990
    Released: June 05, 2006
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    5,6-Dihydro-1,3-dimethyl-6-methylene-5-[(substituted amino)methylene]-2,4(1H,3H)-pyrimidinedione intermediates (E) were characterized spectroscopically and chemically. The cycloaddition reaction of E with olefinic dienophiles was carried out in highly regio- and stereoselective manners to give quinazoline derivatives.
  • Isao Mochida, Kiyoyuki Shimizu, Yozo Korai, Yukio Sakai, Susumu Fujiya ...
    1990 Volume 63 Issue 10 Pages 2945-2950
    Published: 1990
    Released: June 05, 2006
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    The thermal preparation of the mesophase pitch from the isotropic anthracene pitch produced catalytically from anthracene with HF/BF3 was studied through both single- and two-stage heat-treatments. The single stage under vacuum provided a mesophase pitch (SMAP-2) of 100% anisotropy and excellent spinnability at yield as high as 59%. The present mesophase pitch maintained the naphthenic structure to some extent, although thermal preparation, which tends to induce dehydrogenative aromatization, was employed. The two-stage preparation, comprising heat-treatments under pressure (2.1 MPa) and then under vacuum (1 Torr, 1 Torr≈ 133.322 Pa) increased the yield of the mesophase pitch to 64%. The resultant mesophase pitch (TMAP) of 100% anisotropy and excellent spinnability carried fewer aliphatic groups than that of the single stage. SMAP-2 was sufficiently stabilized for 30 min at 300 °C, superior to that of the mesophase pitches derived from FCC-DO and the isotropic naphthalene pitch. The complete stabilization of TMAP with a smaller aliphatic structure was achieved within a slightly longer time of 45 min. The number of aliphatic groups is closely related to the stabilization reactivity. It is worth noting that the present mesophase pitches prepared from the isotropic anthracene pitch retained the structure of the starting pitch to an extent which depended on the procedure, influencing the stabilization reactivity.
  • Yasuzo Sakai, Hiroyuki Kumakura, Fujio Takahashi
    1990 Volume 63 Issue 10 Pages 2951-2955
    Published: 1990
    Released: June 05, 2006
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    A liquid membrane containing ferromagnetic powder (LM-FP) was proposed for controlling the molecular permeation rate through a liquid membrane in a rotating magnetic field (R-MF) in a previous paper. This paper presents details concerning the property of LM-FP under exposure to R-MF or an alternating magnetic field (A-MF). Magnetite and phenylglyoxylic acid (PGA) were used as a ferromagnetic powder and a substance for permeation, respectively. Various factors, such as the magnetite concentration in LM-FP, the intensity of the magnetic field and the number of rotations of R-MF, both of which affect the PGA permeation rate, were investigated in order to understand the behavior of magnetite powder in LM-FP. Magnetized particles of magnetite powder in LM-FP were found to rotate in R-MF, but not to move in A-MF. R-MF exerted an acceleration of the PGA permeation rate through LM-FP more than did A-MF. It is suggested that magnetized particles of magnetite powder behave as micro-magnetic stirrers in LM-FP to accelerate molecular transport. Data concerning the PGA permeation rate were simulated by assuming a concentration change of PGA in LM-FP after turning R-MF on or off. We obtained simulation curves which were in accord with the experimental results.
  • Walid A. Badawi, Mohamed El-Talbi, M. Ahmed Oun, A. Said Abu-Halguma
    1990 Volume 63 Issue 10 Pages 2956-2960
    Published: 1990
    Released: June 05, 2006
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    The molar volume of mixing in the liquid systems Pb–Sn, Pb–Sb, and Pb–Tl has been studied by means of silica glass pycnometer at 1045, 907, and 773 K respectively. The volumes of mixing in the systems Pb–Sn and Pb–Tl are slight positive (0.0263×10−6–0.1767×10−6 m3mol−1), while that in the system Pb–Sb is slight negative (−0.1524×10−6 m3mol−1).
  • William S. Price, Bogdan E. Chapman, Philip W. Kuchel
    1990 Volume 63 Issue 10 Pages 2961-2965
    Published: 1990
    Released: June 05, 2006
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    The relationship between rotational correlation time and the translational diffusion coefficient (Stokes–Einstein equation) of sodium ions dissolved in a series of water–glycerol solutions was studied. NMR longitudinal relaxation measurements gave an estimate of the rotational correlation time for the hydrated sodium ion. From this, using the Debye and Stokes–Einstein equations the translational diffusion coefficient was calculated. These results were compared with estimates of the sodium ion diffusion coefficient obtained using pulsed field gradient NMR. The simple, chemical system was chosen for this study so that the nature of the sodium relaxation would be unambiguous. Also, conductivity measurements were performed on each solution since the conductivity is intimately related to the rate of ionic diffusion. The results showed that due to the spherical nature of the hydrated sodium ion the Debye and Stokes–Einstein equations are well obeyed allowing translational diffusion coefficients to be calculated from rotational correlation times in good agreement with those measured using pulsed field gradient NMR.
  • Alexander A. Koukoulas, M. A. Whitehead
    1990 Volume 63 Issue 10 Pages 2966-2969
    Published: 1990
    Released: June 05, 2006
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    The temperature dependence of the 35Cl nuclear quadrupole resonance frequencies, spin-lattice relaxation times and line widths were analyzed for the presence of a solid–solid phase transition in SiCl4. The brittle phase was verified to temperatures approaching the melting point. Evidence suggesting the formation of a plastic phase at elevated temperature is discussed.
  • R. Jeyalakshmi, B. Jagannadhaswamy, K. Rengaraj, B. Sivasanka
    1990 Volume 63 Issue 10 Pages 2970-2974
    Published: 1990
    Released: June 05, 2006
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    The catalytic properties of mixed oxides La2−xSrxCuO4−y (0.0≤x≤1.0 and y=non-stoichiometry) having K2NiF4 structure were investigated with regard to the effect of changes in the lattice parameters, the oxidation state of copper and oxygen nonstoichiometry in order to correlate the catalytic activity with physicochemical properties. The decomposition of 2-propanol was studied by pulse and flow reactor techniques. The flow reactor data was analyzed by statistical methods to deduce the mechanism on the basis of Langmuir–Hinshelwood and Hougen–Watson models. The reaction followed the first order kinetics with dual site surface reaction as the rate controlling step. The kinetic and thermodynamic parameters obtained from flow reactor data are comparable to those obtained from pulse reactor studies. The higher catalytic activity as indicated by low activation energy and higher conductivity value of La1.8Sr0.2CuO3.96 among the series have been attributed to the presence of higher concentration of Cu(III).
  • P. C. Mandal, D. K. Bardhan, S. N. Bhattacharyya
    1990 Volume 63 Issue 10 Pages 2975-2980
    Published: 1990
    Released: June 05, 2006
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    Aqueous solutions of Cu(II) Metronidazole (CuIIM) at neutral pH were irradiated with 60Co γ-rays under different conditions of radiolysis. The radiolytic formation of HNO2 and CuI was followed. The radiolytic yields of chromophore loss of CuIIM were also determined under different conditions. The OH radicals attack the metal complex to give the OH adducts of the ligand at C2, C4, and C5 either directly or through the formation of Cu(III) species. The C5–OH adduct, however, undergoes oxidative denitration and as a result the metal complex is decomposed. The OH adducts also undergo electron transfer to CuII ion to give reduced complex. No denitration was observed due to the reaction of eeq with the metal complex. On the other hand, the nitro group of the ligand in the complex undergoes successive 4-electron reduction to give hydroxylamino derivative. From the competition kinetics using t-butyl alcohol as the scavenger of OH in N2O saturated solution of the metal complex, the rate constant for the reaction of OH with complex was evaluated to be ca. 2.1×109 dm3mol−1s−1 which is of the same order as that observed in the case of free metronidazole.
  • Salvatore Millefiori, Arcangelo Millefiori
    1990 Volume 63 Issue 10 Pages 2981-2984
    Published: 1990
    Released: June 05, 2006
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    The semiempirical “Effective Pair Correlation Energy” method of Sinanoglu et al. has been employed to investigate the role of the electron correlation energy in the cis-trans, protomeric and dimerization equilibria in the 2-pyridinol (HP2)/2-pyridone (P2) system. CNDO/2 wave functions were used throughly. Preliminary calculations on test cases formic acid, water dimer, and ammonia-water dimer gave acceptable figures in comparison with more accurate literature data. The results show that in HP2 the N–C–O–H cis isomer is more stable than the trans isomer by 2.7 kJ mol−1. Correlation energy favors the trans isomer by 2.9 kJ mol−1 and the keto P2 form over the HP2 form by 11.3 kJ mol−1, in qualitative agreement with results of ab initio calculations. The correlation energy term is stabilizing for the associative process of both tautomers. The numerical data are greatly dependent on the intermolecular equilibrium distance, the best results being obtained at experimental equilibrium distances. (P2)2 dimer is correctly predict to be more stable than (HP2)2 dimer. The correlation energy contribution amounts to 22 and 12.4 kJ mol−1 per hydrogen bond in (HP2)2 and (P2)2, respectively.
  • D. Bourdin, D. Lavabre, J. P. Béteille, G. Levy, J. C. Micheau
    1990 Volume 63 Issue 10 Pages 2985-2990
    Published: 1990
    Released: June 05, 2006
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    Thermochromic and solvatochromic equilibria involving the ions [Ni(tmen)(acac)]+ and [Cu(tmen)(acac)]+ respectively are highly sensitive to the polarity of the solvent. These probes are thus suited for the study of binary mixtures. In nitromethane (NM)/dimethylformamide (DMF) binary solvent the Ni(II) complex displays strong thermochromism in a zone of low DMF concentration. This result is surprising because neither of the two solvents are intrinsically thermochromic since NM is a weak donor while DMF is a strong donor. NM/DMF binary mixtures behave like solvents with intermediate donor properties. In the same solvent mixtures (low DMF concentration), the solvatochromic behavior of the Cu(II) complex is reflected by a large shift in the maximum absorption of more than 70 nm. This was accounted for by the considerable variation in donor power of the solvent mixture in this concentration range. Quantitative analysis of the thermochromic and solvatochromic equilibria as a function of DMF concentration in NM indicated the existence of self-associations of DMF. The relatively small effects of dilution of DMF on the donor properties of the solvent mixture was explained in terms of the discharge of free DMF from self-associations with increasing dilution. In DCE, DMF self-associates to a greater extent than in NM.
  • Giuseppe Buemi
    1990 Volume 63 Issue 10 Pages 2991-2996
    Published: 1990
    Released: June 05, 2006
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    The molecular geometries of the mesoionic 1,3,4-thiadiazolo[2,3-b][1,3]-thiazine-2-thione (II) and its dimerization product, 1,10-dithia[4.4](3,5)-1,3,4-thiadiazolinophane-6,15-dithione (III) have been optimized by means of the AMI method. Their electronic spectra, as well as those of the parent 2,5-dimercapto-1,3,4-thiadiazole (I), have been calculated at CNDO/S level. The analysis of the calculated electronic transitions and of the experimental UV absorption bands confirms the mixed thiolic–thionic structure of I as the most stable one, in agreement with 4-31G* prediction. The electronic transitions of compound III are practically coincident with those found for I; on the contrary, a band in the visible and a band in the UV region are predicted for compound II, so accounting for the yellow color of II and the lack of color of III.
  • Hamad A. Al-Lohedan, Mohammed I. Al-Hassan
    1990 Volume 63 Issue 10 Pages 2997-3000
    Published: 1990
    Released: June 05, 2006
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    Cationic micelles of hexadecyltrimethylammonium ion HTAX (X=Cl and OH) catalyzes the reactions of t-butyl phenyl carbonate with OH and kΨ goes through maximum with increasing [HTACl] but it continues to increase with increasing [HTAOH]. Spontaneous hydrolysis of t-butyl phenyl carbonate is inhibited by both cationic and anionic micelles. The second-order rate constant in micelles is smaller than that in water.
  • S. N. Bhattacharyya, P. C. Mandal, S. Chakrabarti
    1990 Volume 63 Issue 10 Pages 3001-3005
    Published: 1990
    Released: June 05, 2006
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    Aqueous solutions of thymine (T) in the presence of Fe(III) were irradiated under deaerated conditions at pH ≈2. The products of radiolysis were separated by two dimensional thin-layer chromatography. In the absence of any metal ion, the G(-T) is 2.6 but when Fe(III) is present during radiolysis, the G(-T) increases significantly and reaches a limiting value of 3.2. The yields of the hydroxylated products of thymine also increase in the presence of Fe(III). The results were explained by a mechanism which involves the interactions of Fe(III) with the transient adducts of thymine.
  • Kyong Pae Park, Hyun-Joon Ha
    1990 Volume 63 Issue 10 Pages 3006-3009
    Published: 1990
    Released: June 05, 2006
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    Each of E and Z-isomers of activated α,β-dinitro olefins and α-iodo-β-nitrostilbene reacted ith several different types of nucleophiles such as amines, thiocyanate, and p-toluenethiolate. Only Z-isomers of vinylic-substituted olefins with amines and thiocyanate were observed as products due to the attractive interactions between the nitro group of substrate and the nucleophile in the intermediate state. p-Toluenethiolate as a nucleophile could not interact strongly enough to yield a single Z-product but a converged (E) and (Z) mixture of products. Still, preference is toward Z-configuration.
  • Atsuya Takahashi, Tomoo Miyazaki
    1990 Volume 63 Issue 10 Pages 3010-3012
    Published: 1990
    Released: June 05, 2006
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    There has been discussion with regard to the effect of the ζ value, which is a parameter adopted in the Gaussian exponent on the molecular orbital results calculated by use of a basis set extended by their derivatives with respect to ζ. These results are compared with the effect of polarization functions on the molecular orbital results.
  • Keiichiro Hatano, Isao Takeuchi, Yoshiki Hamada, Tamotsu Yashiro, Yuki ...
    1990 Volume 63 Issue 10 Pages 3013-3015
    Published: 1990
    Released: June 05, 2006
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    The crystal and molecular structures of 1-methyl-3,4-benzo-7-thia-2-azabicyclo[3.3.1]non-3-ene 7-oxide have been determined on the basis of three-dimensional X-ray data. The six-membered thiane ring in this novel tricyclic system has been elucidated to adopt a chair-type conformation with an axial-axial aza-phenyl substituent and an equatorial sulfinyl group. The conformation in the solid state was consistent with that previously proposed by molecular mechanics calculations.
  • Tomoyasu Ito, Nobuyuki Tominaga, Toshihiko Tashiro, Keio Toi, Isao Ike ...
    1990 Volume 63 Issue 10 Pages 3016-3018
    Published: 1990
    Released: June 05, 2006
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    MgO pretreated at ca. 823 K in vacuo showed the highest catalytic activity for an isotope equilibration reaction, 2HD=H2+D2, at 195 K. This reaction proceeds through an interaction of dissociatively adsorbed hydrogen on a pair site consisting of lowly coordinated ions, MgLC2+–OLC’2− residual OH at the nearest lattice position.
  • Brian T. Heaton, Javad Sabounchei, Stuart Kernaghan, Hirokazu Nakayama ...
    1990 Volume 63 Issue 10 Pages 3019-3021
    Published: 1990
    Released: June 05, 2006
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    Variable Temperature 13C MAS and 59Co NMR data on solid Co4(CO)12 show that there is a symmetry conserved reorientation of the CO4-tetrahedron which is more restricted than has been reported previously whereas the room temperature 13C MASNMR spectra of Rh4(CO)12 and (NMe3Bz)2[Rh6(CO)15C] are consistent with their solid state static structure.
  • Takashi Shibahara, Mikio Yamasaki
    1990 Volume 63 Issue 10 Pages 3022-3023
    Published: 1990
    Released: June 05, 2006
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    Ammonium hexachloromolydbate(III) (NH4)3[MoCl6] was obtained by tin metal reduction of ammonium molybdate in high yield (80%). The X-ray structure was determined. Crystal data: tetragonal system, space group P42/m, a=8.822(3) Å, c=7.271(2) Å, V=565.9(3) Å3, Z=2, R(Rw)=3.35(5.47). Two independent Mo–Cl distances (2.439(2) and 2.451(1) Å) exist.
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