Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 61 , Issue 7
Showing 1-50 articles out of 79 articles from the selected issue
  • Yukio Chikai, Yukio Yamamoto, Koichiro Hayashi
    1988 Volume 61 Issue 7 Pages 2281-2285
    Published: 1988
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The formation of dimer radical cations of several aromatic olefins has been studied by the pulse radiolysis technique. The aromatic olefins examined are 2-vinylnaphthalene (VN), 2-(1-propenyl)naphthalene (PN), 4-vinylbiphenyl (VBP), trans,trans-1,4-diphenyl-1,3-butadiene (1,4-DPB), and s-trans-2,3-diphenyl-1,3-butadiene (2,3-DPB). The formation of dimer radical cations were observed with all of them except 1,4-DPB, although it was very limited with VBP. Two types of dimer radical cations, bonded and associated ones, are formed with VN, whereas only the associated dimer radical cation is formed with PN. The influence of the aromatic substituents on the formation of the dimer radical cations is described.
  • Kunio Esumi, Hiroyuki Idogawa, Kenjiro Meguro
    1988 Volume 61 Issue 7 Pages 2287-2290
    Published: 1988
    Released: June 27, 2006
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    The colloidal behavior of mixed dispersions containing hematite (diameter=138.9 nm) and silica (diameter=7.0 nm) has been studied by measuring the stability ratio, zeta potential, and particle size. When various particle numbers of silica were added to a constant particle number of hematite, different colloidal behavior was observed, depending on the pH. In a pH region where the two solids were oppositely charged, hematite particles showed a dispersion-coagulation-redispersion process with increasing particle number of silica, resulting in a coating layer of silica particles on the hematite surface. On the other hand, in a region where both solids were negative, the addition of silica enhanced the stability of the hematite.
  • Hiroaki Itagaki, Sumio Shinoda, Yasukazu Saito
    1988 Volume 61 Issue 7 Pages 2291-2294
    Published: 1988
    Released: June 27, 2006
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    Catalytic dehydrogenation of methanol proceeded with homogeneous ruthenium(II) complexes, yielding formaldehyde and dihydrogen as primary products under refluxing conditions of the solution. The effects of additives on the initial reaction rate were examined for lithium chloride, lithium acetate, acetic acid and ethyldiphenylphosphine. A catalyst complex, [Ru(OAc)Cl(PEtPh2)3], was deactivated gradually by the displacement of the bidentate OAc ligand with H and CO ligands during the reaction. These cis-disposed sites would be used for splitting the C–H bonds. A catalytic reaction cycle is proposed, in which such processes are included as solvolysis of the catalyst complex, β-H elimination from the OCH3 ligand and attack of acetic acid on the hydride intermediate to generate dihydrogen.
  • Akinori Maezawa, Masaru Kitamura, Yasuaki Okamoto, Toshinobu Imanaka
    1988 Volume 61 Issue 7 Pages 2295-2301
    Published: 1988
    Released: June 27, 2006
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    The site configuration of Al2O3-supported molybdenum sulfides catalytically active for hydrodesulfurization (HDS) of thiophene has been investigated as a function of pretreatment conditions (H2S/H2=0–0.2) by using X-ray photoelectron, laser Raman and IR spectroscopies and temperature-programmed desorption of adsorbed NO. It has been found that when MoO3/Al2O3 catalysts are presulfided with H2S/H2, MoS2-like species are formed, whereas when prereduced and subsequently sulfided during the HDS reaction, molybdenum oxide sulfides or highly dispersed amorphous molybdenum sulfides are initially produced. The turnover frequency of the HDS reaction calculated on the basis of the NO adsorption was shown to increase with decreasing dispersion degree of sulfided molyb denum. It is proposed that two kinds of NO adsorption sites are present; triply and doubly coordinatively unsaturated (cus) molybdenum sites. It is considered that both sites are catalytically active, possibly, the triply cus species being more active. It is concluded that the HDS activity of sulfided MoO3/Al2O3 catalysts is determined by the structure, dispersion and coordinative unsaturation of sulfided molybdenum.
  • Tadashi Sugano, Takashi Hashida, Akiko Kobayashi, Hayao Kobayashi, Min ...
    1988 Volume 61 Issue 7 Pages 2303-2308
    Published: 1988
    Released: June 27, 2006
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    The semiconductive 2:1 charge-transfer complex between benzo[1,2-c:3,4-c′:5,6-c″]trithiophene and 2,2′-(2,3,5,6-tetrafluoro-2,5-cyclohexadiene-1,4-diylidene)bis[propanedinitrile], (BTT)2(TCNQF4), crystallizes in the monoclinic system, space group P21c, with the following cell constants: a=8.893(2) Å, b=10.589(2) Å, c=18.528(4) Å, β=114.52(1)°, V=1587.5(10) Å3, Dx=1.61 g cm−3, and Z=2. The crystal structure of (BTT)2(TCNQF4) consists of stacking columns of alternating donor dyads and acceptor monads (DAD units) along the crystallographic b axis. Side-by-side sulfur-sulfur contacts shorter than the sum of the van der Waals radii were found along the axis between BTT molecules on the neighboring columns. Polarized reflectance spectra were measured with the single crystal of (BTT)2(TCNQF4) at room temperature, showing a charge-transfer band polarized parallel to the stacking direction. The degree of charge transfer was estimated to be 0.21 from the oscillator strength and the transition energy of the charge-transfer band. From this, as well as the electric and magnetic properties of the complexes and the atomic distances for TCNQF4, it was concluded that (BTT)2(TCNQF4) is a weakly ionized charge-transfer complex.
  • Jun-ichi Aihara
    1988 Volume 61 Issue 7 Pages 2309-2312
    Published: 1988
    Released: June 27, 2006
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    Most organic molecules synthesized in primitive-Earth-simulation experiments conform to the rule of topological charge stabilization. Heteroatoms in these molecules are all located at the best sites to stabilize the conjugated systems. The situation must be the same for organic molecules formed under prebiotic conditions on primitive Earth.
  • Hisao Yanagi, Yasukiyo Ueda, Michio Ashida
    1988 Volume 61 Issue 7 Pages 2313-2320
    Published: 1988
    Released: June 27, 2006
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    Thin films were prepared by the reaction of 1,2,4,5-tetracyanobenzene with Ni, Co, Fe, Zn films at various temperatures. The films were characterized by infrared, UV/visible and photoelectron spectroscopy and analytical electron microscopy in comparison with films prepared on substrates of a KCl single crystal and a Cu film. The films produced on the metal films below 400 °C were composed of tentacle-like crystals growing from the surface and an amorphous layer condensed over the metal substrate. The tentacle-like crystals were soluble in concentrated sulfuric acid and were identified as intercalation compounds of (octacyanophthalocyaninato)metal with the respective metal atoms. The amorphous layers contained polymerization products with a polynitrile structure, which were insoluble in concentrated sulfuric acid. The films produced on the metal films at 450 °C were composed of a thick layer and had a very limited solubility in concentrated sulfuric acid. They were ascribed to metal complexes of polyphthalocyanines(poly-M(Pc)) and cross-linked polymers with structure elements such as polynitrile and triazine.
  • Hiroshi Sasaki, Akihiko Ueno, Tetsuo Osa
    1988 Volume 61 Issue 7 Pages 2321-2325
    Published: 1988
    Released: June 27, 2006
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    Triphenylmethane derivative leukobase (1) was converted to its cation form 2 by UV irradiation. This lipophilic cation form was stable in dichloromethane with green color (λmax=634 nm), and returns to the original colorless form of 1 when shaked with an alkaline solution. Compound 2 exhibited excellent anion extraction ability (from aqueous solution into dichloromethane) under the conditions of appropriate pH, but 1 has no anion extraction ability. Photoinduced active transport of anions across a liquid (dichloromethane) membrane was achieved by using the difference in the extraction ability between 1 and 2 together with the difference in pH between the source and receiving phases.
  • Kazuya Saito, Tooru Atake, Hideaki Chihara
    1988 Volume 61 Issue 7 Pages 2327-2336
    Published: 1988
    Released: June 27, 2006
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    The heat capacities of p-terphenyl and p-terphenyl-d14 were measured by adiabatic calorimetry between 3 and 300 K. The phase transition associated with a molecular conformation change was observed as a λ-shaped anomaly at (193.5±0.1) K and at (180.3±0.1) K. The enthalpies of transition are (304±20) J mol−1 and (288±20) J mol−1 and the entropies of transition are (1.63±0.10) J K−1 mol−1 and (1.63±0.10) J K−1 mol−1, respectively. The anisotropy of the intermolecular interaction is discussed and the anomalous portion of the heat capacities in the transition region was compared favorably with a two-dimensional Ising model.
  • Kenji Okuyama, Naomi Iijima, Kiyoshi Hirabayashi, Toyoki Kunitake, Mas ...
    1988 Volume 61 Issue 7 Pages 2337-2341
    Published: 1988
    Released: June 27, 2006
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    The conformation and molecular packing of ditetradecyldimethylammonium bromide monohydrate (2C14N+2C1Br·H2O), C30H62NBr·H2O, has been determined by the X-ray diffraction method. The crystals are triclinic with the space group P\bar1, Z=2, a=2.9827(9), b=0.7847(3), c=0.7480(3) nm, α=104.69(4), β=90.64(7), and γ=90.84(6)°. The structure was determined by direct methods and refined by the least-squares procedure: R=0.07 (Rw=0.07) for 3335 observed reflections. Two amphiphile molecules of the unit cell are related by centrosymmetry and pack tail to tail in a bilayer structure. The hydrocarbon chains tilt about 45° with respect to the bilayer normal. There are statistically four water molecules with half occupancies in a unit cell. Water molecules and bromide anions make hydrogen-bonding networks along the c-axis in the hydrophilic layer. The above molecular and crystal structure of 2C14N+2C1Br·H2O was quite similar to those of 2C18N+2C1Br·H2O.
  • Tetsuaki Nishida, Setsuko Saruwatari, Yoshimasa Takashima
    1988 Volume 61 Issue 7 Pages 2343-2346
    Published: 1988
    Released: June 27, 2006
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    All the isomer shifts for Li2O–, MgO–, and BaO–V2O5 glasses containing 10 mol% Fe2O3 are in a range of 0.39–0.37 mm s−1, indicating that iron is present as tetrahedral Fe3+ ions. This suggests that all the Fe3+ ions are present at the substitutional sites of tetrahedral V5+ or V4+ ions constituting the skeleton of each glass matrix. Distinct decreases in the quadrupole splitting and the glass transition temperatures are observed when Li2O is incorporated into V2O5 matrix, suggesting a gradual change of the glass matrix from the layer structure originally composed of VO5 tetragonal pyramids to a chain structure composed of VO4 tetrahedra. This structural change is essentially the same as that of Na2O– and K2O–V2O5 glasses. On the other hand, simultaneous increases in the quadrupole splitting and the glass transition temperatures are observed with increasing MgO or BaO content in the case of MgO– and BaO–V2O5 glasses. This suggests a gradual change of the glass matrix from the original layer structure to a highly complicated three-dimensional network structure composed of VO4 tetrahedra, similarly to the case of P2O5–V2O5 glasses.
  • Tetsuaki Nishida, Setsuko Saruwatari, Yoshimasa Takashima
    1988 Volume 61 Issue 7 Pages 2347-2351
    Published: 1988
    Released: June 27, 2006
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    Mössbauer spectra of a series of potassium gallate (Ga2O3-based) glasses, containing 10 mol% Fe2O3 as a Mössbauer probe, consist of two types of quadrupole doublet peaks due to tetrahedral Fe3+ ions bonded with nonbridging and bridging oxygen atoms and those bonded only with bridging oxygen atoms. This indicates that all the Fe3+ ions are present at the substitutional sites of the tetrahedral Ga3+ ions constituting the skeleton of network structure. An increase in the K2O content results in an increased fraction of the FeO4 (and GaO4) tetrahedra bonded with nonbridging oxygen atom(s). A Mössbauer spectrum of 70K2O·20Ga2O3·10Fe2O3 glass consists of only one quadrupole doublet peak due to the FeO4 tetrahedra having nonbridging oxygen atom(s). This suggests that each of the Fe3+ (and also Ga3+) ions is tetrahedrally bonded with at least one nonbridging oxygen atom. Structural information obtained from the Mössbauer measurements is confirmed by DTA measurements of the gallate glasses, Tg of which shows a drastic decrease from 647 to 555 °C when the K2O content is changed from 35 to 70 mol%.
  • Masaki Tachibana, Motohisa Furusawa
    1988 Volume 61 Issue 7 Pages 2353-2357
    Published: 1988
    Released: June 27, 2006
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    Anthraquinone reacts with hydroxylamine in the dimethyl sulfoxide (DMSO) medium containing sodium methoxide and methanol. Since the reaction product is fluorescent in the medium, this reaction can be used for the fluorometric determination of anthraquinone. A DMSO solution of a sample was mixed with a DMSO solution of hydroxylamine hydrochloride and a methanolic solution of sodium methoxide. The mixture was then allowed to stand for 20 min at 60 °C in a volumetric flask with a tightly fitting stopper. After cooling and dilution to the mark with DMSO, the fluorescence intensity of the solution was measured at 597 nm, with excitation at 494 nm. The intensity was stable for at least 2 h in the tightly stoppered flask. The determination limit of anthraquinone was 100 ng. By the application of this spectrofluorimetry, anthraquinone in 9,10-phenanthrenequinone could be successfully determined over the content range from 0.2 to 4%.
  • Hiroshi Kawaguchi, Hironobu Fukaki, Tomoharu Ama, Takaji Yasui, Ken-ic ...
    1988 Volume 61 Issue 7 Pages 2359-2364
    Published: 1988
    Released: June 27, 2006
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    The crystal structure of (−)500CD-mer-[Co(edma)(dien)]Br2·2/3CH3OH·2/3H2O was determined by the X-ray diffraction method. The crystal is triclinic, space group P1, a=13.824(8), b=13.814(8), c=8.055(3) Å, α=101.18(6), β=101.17(6), γ=116.32(5)°, and Z=3. All of the crystallographically independent complex cations, in which the terdentate ligands coordinate meridionally, have a δ spiral configuration, and the asymmetric nitrogen donor atoms of the edma ligands take an S configuration. The racemization reactions due to the inversion at the secondary amine nitrogen atom of the edma ligand in (−)500CD-mer-[Co(edma)(dien)]2+ and (−)514CD-mer-[Co(edma)(mdien)]2+ were studied at 20–35 °C in the pH range of 6.10–7.24. The rate law for both complexes was described as R=k[OH][complex]. The activation parameters at 30.0 °C were ΔH\ eweq of 94.9 kJ mol−1 and ΔS\ eweq of 126 J K−1 mol−1 for the dien complex and ΔH\ eweq of 73.8 kJ mol−1 and ΔS\ eweq of 62.0 J K−1 mol−1 for the mdien complex.
  • Akihito Iida, Mitsuji Yamashita
    1988 Volume 61 Issue 7 Pages 2365-2367
    Published: 1988
    Released: June 27, 2006
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    Chiral diphenylphosphine and diphenylphosphinite derivatives of carbohydrates such as D-glucose, D-galactose, and L-rhamnose were used as the ligand of metal catalysts for asymmetric Grignard cross-coupling reaction. Coupling of s-butylmagnesium bromide with bromobenzene was carried out in the presence of nickel or palladium chloride with the chiral ligand. The highest optical yield was observed when D-galactose ligand was used.
  • Kazunobu Toshima, Kuniaki Tatsuta, Mitsuhiro Kinoshita
    1988 Volume 61 Issue 7 Pages 2369-2381
    Published: 1988
    Released: June 27, 2006
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    Antibiotic elaiophylin (1) has been first synthesized by a convergent route involving aldol coupling of (5R,6R,7R)-5-O-[2-deoxy-3,4-bis-O-(isopropyldimethylsilyl)-α-L-fucopyranosyl]-6-ethyl-7-O-(diethylisopropylsilyl)-5,7-dihydroxy-3-octanone (25f) and (7S,8S,15S,16S:3E,5E,11E,13E)-8,16-bis[(1R)-1-formylethyl]-7,15-dimethyl-1,9-dioxa-3,5,11,13-cyclohexadecatetraene-2,10-dione (3), followed by desilylation. The appropriately O-protected segment 25f and the macrocyclic dialdehyde 3 were synthesized from D-glucose and 2-deoxy-L-fucose.
  • Haruo Ogawa, Nobuo Hiraga, Teiji Chihara, Shousuke Teratani, Kazuo Tay ...
    1988 Volume 61 Issue 7 Pages 2383-2386
    Published: 1988
    Released: June 27, 2006
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    Selective monoesterification of a dicarboxylic acid with longer carbon chains by diazomethane in a mixture of dicarboxylic acids, [dodecanedioic acid (C12) plus glutaric acid (C5), adipic acid (C6), pimelic acid (C7), suberic acid (C8), or sebacic acid (C10)] was achieved by adsorbing and aligning the acids on alumina. The larger the difference in the number of carbon atoms, the higher the selectivity. In the case of the combination of C12 and C5 the highest selectivity was observed and the preferential 89% formation of the monomethyl ester of C12 was obtained in contrast to the 9% formation for the monomethyl ester of C5. Selective reactions were also observed in the case of the combination of C10 and C4, and that of C12 and trans-1,4-cyclohexanedicarboxylic acid.
  • Shinji Nonoyama, Noriyuki Yonezawa, Kazuhiko Saigo, Masaki Hasegawa, T ...
    1988 Volume 61 Issue 7 Pages 2387-2391
    Published: 1988
    Released: June 27, 2006
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    2a-Substituted dichlorodihydrocyclobuta[c]quinolin-3(4H)-one (3) and trichlorovinyl-2-quinolone (4) were obtained from the cross photocycloadduct of 2-quinolone and tetrachloroethylene. The position of the substituent on 3 was determined from the NOE volumes in the NOESY spectrum in comparison with the AM1 geometries. The reaction of the photoadduct (1) with a base or nucleophile, yielding 3 and/or 4, was interpreted to proceed via a cyclobutene intermediate formation followed by an SN2′ displacement or [2+2] cycloreversion.
  • Guan Rong Tian, Shigeru Sugiyama, Akira Mori, Hitoshi Takeshita
    1988 Volume 61 Issue 7 Pages 2393-2399
    Published: 1988
    Released: June 27, 2006
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    The Diels–Alder adduct of tropone with 2,3-bis(methoxycarbonyl)-7-oxabicyclo[2.2.1]hepta-2,5-diene formed homobarrelenone on heating at 130 °C. Similarly prepared were 1-hydroxy-, 3-methoxy-, 1-chloro-, and 3-chlorohomobarrelenones. High-pressure cycloaddition improved the yields of the Diels–Alder adducts. In reactions of 2-methoxy- and 2-chlorotropones with the 7-oxanorbornadiene derivative, the endo-isomers were predominantly produced together with the exo-isomers.
  • Hirokazu Naora, Takashi Ohnuki, Asao Nakamura
    1988 Volume 61 Issue 7 Pages 2401-2404
    Published: 1988
    Released: June 27, 2006
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    A useful prostanoid synthon, 7-(2-hydroxy-5-oxo-1-cyclopentenyl)heptanoic acid (3), was prepared from commercially available cyclooctanone in two steps. Nine other related cyclopentanoids which are also valuable synthons for prostaglandins were obtained from 3 in reasonable yields via several steps. The procedure is capable of generating these useful synthons on a laboratory scale.
  • Takashi Matsumoto, Sachihiko Imai, Noriaki Hayashi
    1988 Volume 61 Issue 7 Pages 2405-2411
    Published: 1988
    Released: June 27, 2006
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    In order to elucidate the absolute configuration of C-15 in natural 16-hydroxydehydroabietic acid, a metabolite of (+)-dehydroabietic acid in rabbits, methyl (+)-dehydroabietate was transformed into methyl (15S)-16-hydroxy-8,11,13-abietatrien-18-oate (3a) and its (15R)-epimer (3b). The synthetic 3a was identical with a methyl ester derived from the natural acid. Thus, the absolute configuration of C-15 in natural 16-hydroxydehydroabietic acid was conclusively assigned as an S-configuration.
  • Masayuki Takada, Kazuhiko Saigo, Teruhisa Hirai, Ikuro Ohchi, Masayuki ...
    1988 Volume 61 Issue 7 Pages 2413-2417
    Published: 1988
    Released: June 27, 2006
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    1,10-Disubstituted 1,4,7,10,13,16-hexaazacyclooctadecanes (hexaaza-18-crowns) having lipophilic groups were synthesized from 1,2-ethanediamine as a starting material. Cyclization of 3,6-ditosyl-3,6-diazaoctanedioyl dichloride and 3,6-ditosyl-3,6-diazaoctane-1,8-diamine under the high dilution conditions, followed by diborane reduction of the amide carbonyl, gave the macrocyclic precursor. A series of reactions, i.e., acylation, diborane reduction, and detosylation, afforded 1,10-disubstituted hexaaza-18-crowns. Their extractability for metal cations was examined by spectrophotometric analysis. They showed relatively high extractability for Ag+, Zn2+, and Cd2+.
  • Noboru Matsumura, Masaaki Tomura, Osamu Mori, Yuko Tsuchiya, Shigeo Yo ...
    1988 Volume 61 Issue 7 Pages 2419-2424
    Published: 1988
    Released: June 27, 2006
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    Symmetrical tetraazapentalene derivatives 5 and 6 were synthesized by a convenient one-pot reaction using lithium thioureide/phenacyl chloride/alkyl (or allyl) isothiocyanate system. Unsymmetrical tetraazapentalene derivatives 8 were prepared by the reaction of various isothiocyanates with thiadiazolopyrimidine derivatives 7 which were derived from symmetrical tetraazapentalene derivatives. The structure of 5c was determined by a single crystal X-ray diffraction.
  • Masahiro Taguchi, Norio Aikawa, Kenzaburo Yoshida, Mikiya Kitamura, Go ...
    1988 Volume 61 Issue 7 Pages 2425-2430
    Published: 1988
    Released: June 27, 2006
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    The reaction of rifamycin S and the quinonic 3-(hydrazonomethyl)rifamycin derivatives with sodium sulfinates under neutral conditions were found to afford the hydroquinone-type 4-O-sulfonyl derivatives of rifamycin. 3-Amino-4-deoxo-4-iminorifamycin S also gave rise to the hydroquinone-type 4-deoxy-4-sulfonylamino derivatives of rifamycin when treated with sodium sulfinates. Under acidic conditions, rifamycin S and 3-bromorifamycin S produced the hydroquinone- and quinone-type 3-sulfonyl derivatives of rifamycin, respectively, by reactions with sodium sulfinates. Some of sodium salts of 4-O-sulfonylrifamycin SV derivatives afforded rifamycin S and sodium sulfinates and/or sodium sulfonates when heated in AcOEt.
  • Masahiro Taguchi, Norio Aikawa, Goro Tsukamoto
    1988 Volume 61 Issue 7 Pages 2431-2436
    Published: 1988
    Released: June 27, 2006
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    Rifamycin S (1) and 25-O-deacetylrifamycin S reacted with 1,3,5-tri-t-butylhexahydro-1,3,5-triazine to give deep-blue compounds. The structures of the deep-blue compounds are discussed based on 13C NMR data, and it is concluded that the earlier structures should be partly re-revised. The mechanism of formation of the deep-blue compounds and the reaction of 1 with several hexahydro-1,3,5-triazines, which were prepared from formaldehyde and primary aliphatic amines, are also described.
  • Masajiro Kawana, Kikuko Takeuchi, Takayo Ohba, Hiroyoshi Kuzuhara
    1988 Volume 61 Issue 7 Pages 2437-2442
    Published: 1988
    Released: June 27, 2006
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    The reaction of appropriately protected 2′-O-tosyladenosines with methylmagnesium bromide (or iodide) gave 9-(2-deoxy-3-C-methyl-β-D-threo-pentofuranosyl)adenine after deprotection. The same reaction on 3′-O-tosyladenosine derivatives afforded an epimeric pair of 2′-C-methyl-3′-deoxy sugar nucleosides. The modified structures of the sugar moieties were determined unambiguously.
  • Kazuo Ashikaga, Shinzaburo Ito, Masahide Yamamoto, Yasunori Nishijima
    1988 Volume 61 Issue 7 Pages 2443-2449
    Published: 1988
    Released: June 27, 2006
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    The triplet-sensitized photochemical reaction using a series of poly(oxyethylene) chains with a pair of photoactive terminal groups, dibenz[b,f]azepine (DBA) chromophores (DBA–COCH2CH2(OCH2CH2)nOCH2CH2CO–DBA, n=0–10) was examined. The photoirradiation of bichromophoric compounds caused either intra- or intermolecular reactions. These reactions were kinetically analyzed by two different methods: the measurement of deactivation processes of the reaction intermediates (excited triplet state of DBA) by nanosecond laser photolysis and the quantitative analysis of the reaction products by GPC. The intramolecular deactivation rate constant, kintra, showed a remarkable chain-length dependence; the maximum kintra value appeared at n=5 and it was found to be 5.9×104 s−1. On the other hand, the intramolecular cyclization rate also depends on the chain length; the maximum quantum yield, φdintra, was given at n=7 (φdintra=0.51). The chain length for the maximum cyclization yield shifted slightly to the longer region than that for the maximum kintra value due to the restriction of the terminal structure (anti-configuration). The results obtained for this reaction system are compared with those obtained for the previously reported polymethylene system and the effect of chain flexibility on the intramolecular ring-closure reaction is discussed.
  • Yoshiro Yamashita, Takaaki Hanaoka, Yasuyuki Takeda, Toshio Mukai, Tsu ...
    1988 Volume 61 Issue 7 Pages 2451-2458
    Published: 1988
    Released: June 27, 2006
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    2,3-Dipyridylnorbornadienes were prepared using the Diels–Alder reaction of the HBF4 salts of dipyridylacetylenes with cyclopentadiene. Their absorptions extend to 380 nm and are red-shifted in an acidic media. They underwent photocyclization to give quadricyclanes which reverted to norbornadienes upon heating or encountering a Co(II)–TPP catalyst. 2,3-Bis(1-methylpyridinio)norbornadienes were also prepared by a Diels–Alder reaction of bis(1-methylpyridinio)acetylenes with cyclopentadiene. Irradiation of 1-methyl-2-pyridinio and 1-methyl-3-pyridinio derivatives led to the photostationary state between them and the corresponding quadricyclanes, while a 1-methyl-4-pyridinio derivative gave a water or methanol adduct in the presence of water or methanol. Electron-transfer reactions of bis(1-methylpyridinio)norbornadienes were investigated by cyclic voltammetry. The radical cations formed by their reduction were unstable compared with those of the corresponding trans-bis(1-methylpyridinio)ethylenes. Steric factors were shown to strongly affect the reactivities.
  • Sadatoshi Akabori, Takeshi Kumagai, Yoichi Habata, Sadao Sato
    1988 Volume 61 Issue 7 Pages 2459-2466
    Published: 1988
    Released: June 27, 2006
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    The reaction of o-bis(3-hydroxy-1-oxapropyl)benzene (7b) with 3,3′-(trimethylenedi-4,1-phenylene)bis[2-propenoyl chloride] gave 8,9-benzo-4,7,10,13-tetraoxa[16.3]paracyclopha-1,8,15-triene-3,14-dione (8b) in a 6.5% yield, together with its dimer in a 12.3% yield. Also, 5,6-benzo-4,7-dioxa[10.3]paracyclopha-1,5,9-triene-3,8-dione (8a) and 11,12-benzo-4,7,10,13,16,19-hexaoxa[22.3]paracyclopha-1,11,21-triene-3,20-dione (8c) were obtained by the same method in 7.0 and 8.0% yields, together with their respective dimers (9a: 6.0%, 9c: 10.8%). X-Ray analysis of 8b revealed the two double bonds to be trans and the distances between the two olefinic carbon atoms (C17–C35) and (C18–C34) to be 5.341(11) and 5.906(9) Å respectively. These distances are too long for intramolecular [2+2]photocycloaddition to occur in the crystalline state. However, the irradiation of the solutions of the crown ethers 8a and 8b in acetonitrile by Pyrex-filtered UV light (>300nm) gave two intramolecular [2+2]photocycloadducts, cyclobutanocrown ethers 10a and 10b, in 95.7 and 91.8% yields respectively. Subsequently, 10a and 10b were transformed to 8a and 8b in 37 and 29% yields respectively upon irradiation with 220 nm UV light. The structures of 10a and 10b were confirmed to be the β-form.
  • Sho Takahashi, Takeshi Hibino, Seiji Sawada
    1988 Volume 61 Issue 7 Pages 2467-2471
    Published: 1988
    Released: June 27, 2006
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    To study a charge-induced stabilization of α-helix, α-helical peptides having a positively charged random-coil block on either N- or C-terminal of the helix, and having a strictly defined length, (Ala)20(X)20Phe and (X)20(Ala)20Phe (X=Lys or Orn), were synthesized. Component dipeptides were coupled on p-(oxymethyl)phenylacetamidomethyl polystyrene.
  • Mayumi Tanaka, Osamu Oota, Hideo Hiramatsu, Kazuyoshi Fujiwara
    1988 Volume 61 Issue 7 Pages 2473-2479
    Published: 1988
    Released: June 27, 2006
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    The Knoevenagel reactions of p-nitrobenzaldehyde (1) with β-keto acids, methylmalonic (2a) and α-methylacetoacetic acids (2b) were carried out in the presence of a tertiary amine such as pyridine. We have isolated the corresponding β-hydroxy intermediate (3a) by the reaction of 2a which positively suggested the reaction proceeded by the Hann and Lapworth mechanism. A kinetic study using 1H NMR revealed the existence of the reversibility between the starting materials and the β-hydroxy intermediate and that the rate determining step was decarboxylattion. But, when using the secondary amine, both the β-hydroxy acid and the corresponding condensation product were obtained via this reaction. These findings led to the conclusion that the reaction proceeded according to the two competing mechanisms, i.e., the Hann and Lapworth and Knoevenagel mechanisms. It was further clarified that either the decarboxylation step or the formation of the bis(dialkylamino) derivative was the rate determining step. The stereoselectivity of the β-hydroxy saturated compound has been closely related to the fact that the conformation of the intermediate possesses an intramolecular hydrogen bond to a hydroxyl group.
  • Ryu Sato, Michiko Ohmori, Fumiko Kaitani, Akiko Kurosawa, Toshihide Se ...
    1988 Volume 61 Issue 7 Pages 2481-2485
    Published: 1988
    Released: June 27, 2006
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    Various 3,3-dialkoxy-2,3-dihydro-1-hydroxy-1H-isoindoles (2) were obtained by treating 2-cyanobenzaldehyde (1) with alcohols in the presence of an acid catalyst such as silica gel. In the reaction using a base catalyst such as triethylamine and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 3-alkoxy-2,3-dihydro-1H-isoindol-1-ones (4) were formed via 3-alkoxy-1,3-dihydro-1-isobenzofuranimine (3). The use of 1,4-diazabicyclo[2.2.2]octane (DABCO) and N,N,N′,N′-tetramethylethylenediamine (TMEDA) gave 2 besides 3 and 4. A convenient and selective synthesis of isoindoles and its derivatives are described.
  • Yukie Mori, Yuji Ohashi, Koko Maeda
    1988 Volume 61 Issue 7 Pages 2487-2491
    Published: 1988
    Released: June 27, 2006
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    The crystal and molecular structures of 2,2,4,6-tetraphenyldihydro-1,3,5-triazine acetone solvate (1) which turns red on exposure to UV light, and 2-propanol solvate (2) which shows no photocoloration, have been determined by the X-ray method. The crystals of both inclusion compounds are monoclinic. For 1 the space group is P21n; Z=4, with a=16.385(2), b=11.987(2), c=12.939(2) Å, and β=92.24(2)°. For 2 the space group is C2⁄c; Z=8, with a=21.967(3), b=13.418(1), c=19.576(4) Å, and β=118.73(1)°. The final R values were 0.082 and 0.083 for 1 and 2 respectively. In both crystals, the dihydrotriazine ring exists in 2,3-dihydro form, which is one of the two possible tautomeric forms. In 1 each acetone molecule interacts with only one molecule of tetraphenyldihydrotriazine by N(3)–H(3)···O hydrogen bond, while in 2 tetraphenyldihydrotriazine and 2-propanol molecules are alternately connected by N(3)–H(3)···O and N(5)···H–O hydrogen bonds to construct a ribbon-like structure. It was suggested that the N(3)–H(3)···O–H···N(5) hydrogen bonds which exist in 2 but not in 1 inhibit photocoloration of 2.
  • Hitoshi Saito, Yoshio Nishimura, Shinichi Kondo, Keiko Komuro, Tomio T ...
    1988 Volume 61 Issue 7 Pages 2493-2497
    Published: 1988
    Released: June 27, 2006
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    1-O-(2-Aminoethyl)-4′-O-demethyl-1-epipodophyllotoxin derivatives were synthesized by a stereoselective BF3-catalyzed coupling of 4′-O-benzyloxycarbonyl-1-epipodophyllotoxin with the corresponding 2-aminoethanol derivatives, and with ethylene glycol followed by reductive amination of its aldehyde. Some 1-O-(2-aminoethyl) ethers of 4′-O-demethyl-1-epipodophyllotoxin prolonged markedly survival periods in mice with leukemia L-1210.
  • Tadashi Hanaya, Nobuyuki Shigetoh, Hiroshi Yamamoto
    1988 Volume 61 Issue 7 Pages 2499-2505
    Published: 1988
    Released: June 27, 2006
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    Treatment of 5-deoxy-5-iodo-1,2-O-isopropylidene-3-O-methyl-α-D-xylofuranose with ethyl phenylphosphinothioate in the presence of NaH in DMF gave a 1:1 mixture of the 5-deoxy-5-C-[(R)- and (S)-(ethoxy)phenylphosphinothioyl] derivatives. Reduction of these D-xylofuranoses with sodium dihydrobis(2-methoxyethoxy)aluminate, followed by the acid hydrolysis, provided the title compounds, which are the first sugar analogues having a phosphinothioyl group in the hemiacetal ring. These compounds were converted into four, separable 1,2,4-tri-O-acetates, the structures and conformations of which were established by spectroscopy. The corresponding per-O-acetyl-5-deoxy-5-C-[(R)- and (S)-phenylphosphinyl] analogues were also prepared and their previously presented structures were revised. Complete 1H NMR (500-MHz) parameters of these two types of compounds are given for a comparative, structural study.
  • Takumi Oshima, Toshikazu Nagai
    1988 Volume 61 Issue 7 Pages 2507-2512
    Published: 1988
    Released: June 27, 2006
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    Unsubstituted 1,4-benzoquinone (1a) reacted with diphenyldiazomethane (DDM) at the C=C double bonds to give dihydroxy-3H-indazole (2a) and its benzhydryl ether (3a) together with benzodipyrazole derivative (4a). Similarly, reactions of 2-chloro- and 2,3-dichloro-1,4-benzoquinones (1b and 1c) with DDM yielded the corresponding dihydroxy-3H-indazoles (2b, 2b′, and 2c) and their benzhydryl ethers (3b, 3b′, and 3c) along with 5–13% benzophenone (6). On the other hand, reaction of 2,6-dichloro-1,4-benzoquinone (1e) with DDM gave bicyclic 5e and tricyclic diones (7e), together with benzophenone dimethyl acetal (9) in the presence of added methanol. In the same conditions, 2,3,5-trichloro-1,4-benzoquinone (1f) provided bicyclic dione (5f) and 9. Formation of 6 and 9 was interpreted as arising from the hydrolysis and methanolysis of the 1:1 betaine intermediates given by the addition of DDM to the quinonoid C=O double bonds. The C=O addition increased with increasing chlorine substituents.
  • Otohiko Tsuge, Shuji Kanemasa, Kazushige Sakamoto, Shigeori Takenaka
    1988 Volume 61 Issue 7 Pages 2513-2524
    Published: 1988
    Released: June 27, 2006
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    Highly stabilized isoquinolinium methylides bearing two electron-withdrawing substituents at the ylide carbon undergo cycloadditions with aryl-substituted olefins (acenaphthylene, (E)- and (Z)-stilbenes, indene, and styrene), alkyl-substituted olefins (norbornene, (Z)-3-hexene-1,6-dinitrile, 1-hexene, 2-propen-1-ol, and 3-(trimethylsilyloxy)propene), and electron-rich olefins (vinylene carbonate, butyl vinyl ether, and phenyl vinyl sulfide). These cycloadditions proceed in an exclusively regioselective and mostly stereoselective manner.
  • Kuniaki Tatsuta, Yoshihito Koguchi, Motohiro Kase
    1988 Volume 61 Issue 7 Pages 2525-2530
    Published: 1988
    Released: June 27, 2006
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    The optically active 1,3,5-trihydroxy-2,4-dimethylpentane equivalents: methyl 2,4-dideoxy-2,4-di-C-methyl-α-D-ido- and talopyranosides and their enantiomers, which should be suitable for the syntheses of propionate-derived natural products, were stereo- and regioselectively prepared from methyl α-D- and L-mannopyranosides through the reactions of the 3,4-anhydro-2-O-mesyl- and 3,4-anhydro-2-C-methylaltropyranoside derivatives with methylmagnesium bromide and methylmagnesium chloride.
  • Tetsuo Nozoe, Kimiaki Imafuku, Bing-Zhu Yin, Masaaki Honda, Yasutomo G ...
    1988 Volume 61 Issue 7 Pages 2531-2539
    Published: 1988
    Released: June 27, 2006
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    A wide variety of 2-(2-arylhydrazino)tropones were prepared by the reactions of 2-tosyloxytropone with arylhydrazines. The dimeric compounds 6,6′-bis(arylhydrazono)-1,1′-bi(2,4-cycloheptadiene)-7,7′-diones, 2-anilinotropones, and 3-(2-arylhydrazino)tropones were isolated as minor products in some cases. Similarly, starting with 2-tosyloxytropones bearing an isopropyl, isopropenyl, (1-acetamidoethyl), and protected acetyl group at the 5-position, 4-substituted 2-(2-arylhydrazino)tropones were obtained as the major products by the abnormal substitution reaction. These 2-(2-arylhydrazino)tropones are expected to effectively serve as precursors for a convenient synthesis of 5-aryl-substituted tropolones via benzidine-type rearrangement. 1H NMR (200 or 500-MHz) parameters for these 4-substituted 2-(2-arylhydrazino)tropones are given for their unambiguous structural assignments.
  • Michio Noda, Sumio Shinoda, Yasukazu Saito
    1988 Volume 61 Issue 7 Pages 2541-2545
    Published: 1988
    Released: June 27, 2006
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    A platinum-deposited nickel fine-particle catalyst was shown to be more active than a nickel-alone catalyst. A study of the temperature dependence of a rate constant revealed that platinum increased the frequency factor of the rate constant. An experiment regarding poisoning showed that the number of active sites was the same for the two catalysts. Thus the promoter effect was ascribed to an increase in the frequency factor per active site.
  • Kaoru Fujimoto, Hitoshi Saima, Hiro-o Tominaga
    1988 Volume 61 Issue 7 Pages 2547-2550
    Published: 1988
    Released: June 27, 2006
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    Hybrid catalysts composed of the physical mixture of methanol synthesis catalysts and Y-type zeolites gave C3 and C4 paraffins from synthesis gas at 2.1 MPa, with a selectivity higher than 70%. The product contained small methane and little aromatic hydrocarbons. The hydrid catalyst kept its activity and selectivity at almost constant level for 50 h. The yield of hydrocarbon was much higher than the level estimated from the thermodynamic equilibrium of methanol formation from synthesis gas. The yield of hydrocarbon increased monotonically with the increase in temperature while the carbon number distribution of the product shifted to lower side between 523 and 623 K. The production of hydrocarbon was accompanied by the nearly equal amount of CO2.
  • Naoki Toshima, Keiichi Kanaka, Atsunori Koshirai, Hidefumi Hirai
    1988 Volume 61 Issue 7 Pages 2551-2557
    Published: 1988
    Released: June 27, 2006
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    The polymerization of benzene to poly(1,4-phenylene) (PPP) has been done successfully using copper(I) chloride and aluminium chloride as catalysts under oxygen. Since copper(I) chloride and aluminium chloride form a double salt (aluminium copper(I) chloride, AlCuCl4) and are soluble in benzene, a high homogeneity of the reaction system has been achieved and the polymerization reaction proceeds without any evolution of hydrogen chloride. The polymerization products contained an insoluble dark brown solid and a benzene-soluble tarry mass. The solid product has been determined to be PPP by comparison with an authentic sample. The product PPP was obtained in a yield of more than 100%, based on the molar quantity of copper(I) chloride, by controlling the quantity of aluminium chloride. For example, the treatment of benzene with aluminium chloride and copper(I) chloride (20:3:1 in molar ratio) under 1 atm of oxygen at 70 °C for 24 h gave PPP in a 187% yield, based on copper(I) chloride. This reaction could be carried out by the use of oxidants other than oxygen and by the use of low-valent metal salts other than copper(I) chloride, although a copper(I) chloride–aluminium chloride–oxygen system is most suitable for the polymerization of benzene in terms of the yield of PPP and the convenience of the reaction.
  • Hyernjoo Kim, Akiko Kobayashi, Yukiyoshi Sasaki, Reizo Kato, Hayao Kob ...
    1988 Volume 61 Issue 7 Pages 2559-2562
    Published: 1988
    Released: June 27, 2006
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    The crystal structure of tetrabutylammonium salt of a new multi-sulfur 1,3-dithiolene complex, (Bun4N)[Ni(ddt)2] (ddt=1,4-dithiin-2,3-dithiolato) has been determined by the single-crystal X-ray diffraction technique. Crystals are monoclinic, space group C2⁄c, a=66.107(40), b=9.182(5), c=19.119(12) Å, β=147.29(3)°, V=6271(1) Å3, and Z=8. The structure was solved by the heavy atom method, and refined by a block-diagonal least-squares method to R=0.070. There are two crystallographically independent molecules of Ni(ddt)2, molecule-A and molecule-B. Molecule-B forms segregated uniform stacks along the b-axis. The (Bun4N)+ cations are located between two molecular planes of molecule-A. The Ni(ddt)2 molecules are almost planar except two terminal vinylene moieties, which are folded to opposite side each other and the folding angles of molecule-A and molecule-B are 28° and 39°, respectively.
  • Fujiko Iwasaki, Nobuhiko Toyoda, Ryouichi Akaishi, Hisashi Fujihara, N ...
    1988 Volume 61 Issue 7 Pages 2563-2567
    Published: 1988
    Released: June 27, 2006
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    The crystal structure of 1,5-dithioniabicyclo[3.3.0]octane bis(trifluoromethanesulfonate) has been determined by the X-ray method to elucidate the structure of a dithionia dication. Crystal data; C6S2H122+·2CF3SO3, Fw=446.43, orthorhombic, Pccb, a=16.775(2), b=9.893(3), c=19.592(3) Å, V=3251(1) Å3, Z=8, Dx=1.825 Mg m−3. There are two independent dications, A and B, in the crystals, each of which has a crystallographic twofold axis. The mean S+–S+ distance is 2.124 Å. The conformation of the eight-membered ring is a distorted chair–chair form. Very strong interactions were observed between S+ of dications and O atoms of counter anions. The average distance of S+···O is 2.724 Å and colinear arrangements of O···S–S···O are formed with the central twofold axis. Other weak S···O interactions (2.903–3.153 Å) were also observed between dications and anions. The coordination around S is a roughly distorted octahedron with two C and two O atoms in a plane and apical S and O atoms.
  • Hirokazu Toriumi, Toru Shimmura, Hiroshi Watanabe, Hazime Saitô
    1988 Volume 61 Issue 7 Pages 2569-2571
    Published: 1988
    Released: June 27, 2006
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    A 2H NMR study of discotic benzenehexayl hexaheptanoate carrying perdeuterated alkyl side chains (BH7-d78) is reported. Solid-state 2H NMR measurements reveal that the conformational transition of the heptanoate chains takes place at 230 K from nearly static to mobile state. The chains above 230 K undergo flip-flop type reorientational motion, with the degree increasing upon heating. This temperature coincides with the solid-to-solid phase transition temperature, indicating that the phase transition takes place accompanied by the conformational melting of the flexible alkyl side chains. A spectrum measured in the discotic mesophase is also reported.
  • Jun Nakauchi, Yoshitaka Kageyama
    1988 Volume 61 Issue 7 Pages 2573-2578
    Published: 1988
    Released: June 27, 2006
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    Six homologous series of novel ferroelectric liquid crystals containing α-methylcinnamoyl moiety in the core structure:
    (Remark: Graphics omitted.)
    (IA: k=1, l=1, (Remark: Graphics omitted.), n=8–16; IB: k=1, l=1, (Remark: Graphics omitted.), n=8–16; IIA: k=1, l=2, (Remark: Graphics omitted.), n=9–16; IIB: k=1, l=2, (Remark: Graphics omitted.), n=8–14, IIIA: k=2, l=1, (Remark: Graphics omitted.), n=9–16; IIIB: k=2, l=1, (Remark: Graphics omitted.), n=9–16) have been synthesized and their thermal and ferroelectric properties have been investigated. The mesomorphic transition temperatures and the spontaneous polarization for the homologous series (IA, IB, IIA, IIB, IIIA, and IIIB) depend on the core structure, the chiral group, and the terminal alkoxyl chain length. These homologous series show the chiral smectic C phase over wide temperature ranges including room temperature and the values of their maximum spontaneous polarization are in the range of 30 to 800 μCm−2. The thermal stability of the mesophase and the magnitude of the spontaneous polarization have been discussed from the view point of the molecular structure and the local molecular interactions.
  • Masayoshi Maehara, Toshikazu Hieida, Yoshinori Nibu, Hiroko Shimada, R ...
    1988 Volume 61 Issue 7 Pages 2579-2583
    Published: 1988
    Released: June 27, 2006
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    The low-frequency Raman bands of the tetramethyl- and tetramethyl-d12-pyrazine crystals and their hydra ted crystals were studied at various temperatures between 4.2 and 298 K. The isotopic factors and the temperature effects on the frequencies of the Raman bands indicate that the low-frequency Raman bands observed in the crystal are to be ascribed to the rotational lattice vibrations. A smooth curve of the plot of the Raman frequency versus temperature suggests that no apparent temperature-induced phase transition takes place in the tetramethylpyrazine crystal. Classification of the rotational lattice vibrations into symmetry species was made based on the polarization behavior of the Raman bands. It was also observed that tetramethylpyrazine hydrates quite easily with a trace of moisture in the air.
  • Shigeo Ted Oyama
    1988 Volume 61 Issue 7 Pages 2585-2594
    Published: 1988
    Released: June 27, 2006
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    Samples of MoO3 consisting of unsupported oriented crystallites exposing primarily the (010) plane and of randomly oriented powders were used to study the partial oxidation of propylene and allyl iodide. The materials were characterized by scanning electron microscopy, X-ray diffraction, infrared spectroscopy, laser Raman spectroscopy, temperature programmed desorption of ammonia and surface area measurements. The unoriented powders were twice as active as the oriented crystallites in the oxidation of propylene, but both were similar in activity in the oxidation of allyl iodide. Thus, the reactions depended only slightly on the structure of the MoO3.
  • P. V. S. S. Prabhu, M. V. Ramanamurti
    1988 Volume 61 Issue 7 Pages 2595-2603
    Published: 1988
    Released: June 27, 2006
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    Conductance data for alkali metal chlorides and ammonium chloride in 1,2-dimethoxyethane (DME)–water mixtures (14.00<dielectric constant<56.76) at 25 °C are reported in the concentration range 0.0001–0.06 mol·dm−3. The data have been analyzed by Fuoss (1978) conductance–concentration relation. Preferential solvation of cations by water does not show systematic trend depending on the cationic size. Walden product variations indicated the complex dependence of conductance of alkali metal cations on solvent sorting and structural effects. The energy (Es) values suggest that alkali metal cations and chloride ions in majority exist as contact pairs in these solutions.
  • Ratan Lal Gupta, Kochi Ismail
    1988 Volume 61 Issue 7 Pages 2605-2608
    Published: 1988
    Released: June 27, 2006
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    Electrical conductance measurements of [xNaSCN+(1−x)KSCN]+RH2O system were made as functions of x and R at 25 °C. The mixed alkali effect was found to be negligible when R>10 and it increased sharply with increase in concentration in the range R≤10. The concentration dependence of molar conductance (Λ) has been described satisfactorily by the expression, Λ=ΛFHexp (Bm+Cm2) where ΛFH is the Falkenhagen–Leist–Kelbg equation for Λ, m is the molality and the parameters B and C are the empirical constants.
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