Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 52 , Issue 5
Showing 1-50 articles out of 67 articles from the selected issue
  • Tooru Inoue, Tadashi Watanabe, Akira Fujishima, Kenichi Honda
    1979 Volume 52 Issue 5 Pages 1243-1250
    Published: 1979
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The study of the photoanodic reaction in the CdS/S2− system was carried out by means of the rotating ring-disk electrode (RRDE) technique. The photoanodic reactions at an n-type CdS electrode are divided into two types; the photoanodic oxidation of redox agents in the electrolyte solution and the photoanodic dissolution of CdS electrode surface. The stabilization of a CdS photoanode could be attained through the preferential progress of the former of these two processes. The ratio between these two processes depends upon the concentration of S2− in the electrolyte solution and the light intensity. Sulfide ion in the electrolyte solution stabilizes CdS photoanode and gives rise to the shift of the flatband potential of CdS electrode by ca. −60 mV/log[S2−]. This dependence of the flatband potential on sulfide ions can be explained by an adsorptive dissociation equilibrium at a CdS electrode surface. The results of the photoanodic reaction were disscussed referring to the charge transfer process with the participation of some surface energy state within a bandgap.
  • Fumitaka Yamashita, Tsuyoshi Komatsu, Tsurutaro Nakagawa
    1979 Volume 52 Issue 5 Pages 1251-1254
    Published: 1979
    Released: April 19, 2006
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    The complex formation of bivalent transition metal ions, Mn(II), Co(II), Ni(II), Cu(II), and Zn(II), with copoly(maleic acid–ethylene) and copoly (maleic acid-styrene) in aqueous solution was studied by potentiometric titration at 25 °C and the ionic strength of 0.1. The systems containing copper(II) ions were investigated by potentiometry employing the copper(II) ion-selective electrode. The titration curves of the bivalent metal–copoly(maleic acid–ethylene) systems were situated in a lower pH region than in the absence of the metal ions. The complex formed involves two carboxylate groups: primary and secondary. The equilibrium constant of the copper(II) complex was estimated to be 10−2.6. In copoly (maleic acid–styrene) systems, however, the titration curves in the absence and presence of bivalent metal ions overlapped partly in the first neutralization step. From the potentiometric results employing the ion-selective electrode, it was observed that the concentrations of copper(II) ions decrease slightly in the region of overlap. This anomalous behavior is due to the acid dissociation influenced by the conformational transition, including the effect of the side groups of the polymers.
  • Hidekazu Hamano, Hiroshi Kondo
    1979 Volume 52 Issue 5 Pages 1255-1259
    Published: 1979
    Released: April 19, 2006
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    The unrestricted Hartree-Fock perturbation technique was applied to the calculation of spin densities in many hydrocarbon radicals. The method is similar to that of McLachlan but contains partly the SCF and projection procedures. The results agree with the more rigorous SCF ones.
  • Niro Kikuchi, Takashi Maekawa, Toshio Yokokawa
    1979 Volume 52 Issue 5 Pages 1260-1263
    Published: 1979
    Released: April 19, 2006
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    The Si Kα and Kβ spectra of several silicates were measured. The Kα spectra showed negative energy shifts referred to SiO2; these are consistent with the results for the binary silicate glasses. On the other hand, the Kβ shifts were positive and the absolute values were about ten times as large as the Kα shifts in each compound. A linear relation was observed between Kα and Kβ energy shifts. The Si 1s energy shift for the orthosilicate was estimated from the Kβ spectral splitting of Na2Si2O5. The stability of the silicon–oxygen bond was discussed with the aid of the shifts in Kβ and the Si 1s. The above linear relation suggests that the silicon–oxygen bond strength is lowered (the Kβ energy is increased) with decreasing Goulombic interaction (lowering Kα energy) between silicon and oxygen in the silicates.
  • Kotaro Araya, Yoshio Matsunaga, Eiji Ochi
    1979 Volume 52 Issue 5 Pages 1264-1267
    Published: 1979
    Released: April 19, 2006
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    The ESR spectrum of bis(dibenzoylmethanato)oxovanadium(IV) dissolved in a number of pyrene and fluoranthene complexes with aromatic polynitro compounds just above their melting points indicates that the motion of the spin probe is more or less restricted. In some favorable cases, the high effective viscosity of the melts can be partially attributed to the association of the electron donor and acceptor molecules. No abrupt change in the ESR spectral pattern is noted upon solidification and the motion of the probe gradually ceases upon lowering the temperature. Therefore, the lattice appears to be not rigid in these crystalline complexes. On the other hand, the ESR spectrum observed in the molten naphthalene-dinitrophenol complex is not far from isotropic at the melting point. Because of the segregation of the probe upon solidification, the measurements on this solid complex could not be made.
  • Yoshiya Kera, Keiji Kuwata
    1979 Volume 52 Issue 5 Pages 1268-1274
    Published: 1979
    Released: April 19, 2006
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    The V2O5 crystal, prepared from the pure V2O5 powder by a zone-melting method in the air, did not show any ESR signal. When the crystal came into contact with a mixture of CO and O2 ((CO/O2)≥4), an ESR spectrum with the hfs of 15-lines (g⁄⁄=1.932, g=1.978; ⟨g⟩=1.963), which has been previously ascribed to an oxygen defect, was found at the beginning, but after prolonged contact a sharp spectrum (⟨g⟩=1.954) appeared. The intensity of the hf-lines was constant but that of the sharp spectrum increased with the contact time. The g-value and line shape of both spectra did not change with the contact time. The same spectra were also found in the crystal grown under a mixture of CO and O2. On the thermal decomposition of pure NH4VO3 in vacuo a similar spectrum with a sharp line was found. The g-value became lower in the sample reduced further by SO2 after the thermal decomposition. With reference to the data of TGA, DTA, magnetic susceptibility (χmol), and X-ray analysis of the vanadium oxides, the sharp spectrum was ascribed to a lower oxide or oxide state such as V3O7. Based on the ESR results, the working state of pure V2O5 crystal under CO-oxidation and its catalytic property are discussed.
  • Koe Enmanji
    1979 Volume 52 Issue 5 Pages 1275-1278
    Published: 1979
    Released: April 19, 2006
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    The NMR relaxation time of the Cu-chlorophyllin (Cu-chln)–flavine mononucleotide (FMN) complex was measured, and its geometrical structure was proposed. The complex has an absorption band at 700 nm which is attributed to complex formation by analogy with the chlorophyll a–FMN complex. Its binding constant is 330 l/mol at 25 °C; this value is larger than those of other Cu-chln complexes. From the analysis of its ESR data, it is clear that the greater part of the electron spin in Cu-chln is distributed on the Gu2+ ion. The distance between the nuclear and electron spins was calculated by measuring the spin-lattice relaxation times. From these results, the distance between the porphyrin ring and the isoalloxazine ring in the Cu-chln-FMN complex molecule is found to be 4.2 Å if the two rings are parallel to each other. The chlorophyll a-FMN complex is assumed to have a similar geometrical structure.
  • Keijiro Taga, Keiichi Ohno, Hiromu Murata
    1979 Volume 52 Issue 5 Pages 1279-1285
    Published: 1979
    Released: April 19, 2006
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    The infrared and Raman spectra of 3-butenylsilane, CH2=CHCH2CH2SiH3 (and –SiD3), were measured for the gaseous, liquid, and solid states. The fundamental vibrations were assigned, and the normal vibrations were calculated in relation to the rotational isomerism. The calculations indicated that the cis-trans (CT), skew-trans (ST), and skew-gauche (SG and SG′) forms coexist in the gaseous and liquid states, while the CT form only persists in the solid state. From the temperature variation in the Raman intensities, the stability of the molecular conformations was found to be in this order: CT\gtrsimST>SG′>SG in the liquid state, indicating that an appreciable interaction between the silicon atom and the C=C bond, such as in the case of allylsilane, is not present for 3-butenylsilane.
  • Kiwamu Yamaoka, Tsutomu Masujima
    1979 Volume 52 Issue 5 Pages 1286-1296
    Published: 1979
    Released: April 19, 2006
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    The visible-UV absorption and circular dichroism, CD, of poly(α-L-glutamic acid)–Cu(II) solutions have been measured at 25 °C in the pH range 7 to 3.5 and at the mixing ratio, R, (Glu residues-to-Cu2+) 32 to 4. Complex formation between poly (Glu) and Cu2+ was evident from the three absorption bands of bound Cu(II) around 700, 370, and 250 nm. The molar absorption coefficients, ε, varied with pH and R in a complicated but systematic manner. The pH dependence of ε, however, was not in parallel with the helix-coil transition of poly(Glu)–Cu(II) complexes. The extrinsic CD bands of bound Cu(II) have been detected in the three absorption band regions, and found to depend on both pH and R. The optical dissymmetry factor indicated that the 700 and 250 nm absorption bands of bound Cu(II) are associated with multiple CD bands of opposite signs. The intrinsic CD showed that the Cu(II)- and pH-induced helices of the poly(Glu)–Cu(II) complex are alike regarding the polymer backbone.
  • Yukio Yoneda
    1979 Volume 52 Issue 5 Pages 1297-1314
    Published: 1979
    Released: April 19, 2006
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    A new group-contribution method for estimating the standard enthalpy of formation, the standard absolute entropy, and the standard molar heat of organic compounds in the ideal gas state is proposed with tables of the contribution values. This method (the ABWY method) is a completely revised and enlarged version of the Anderson, Bayer, and Watson method, and it can be used with regard to a more diverse variety of compounds with a higher reliability. The neighboring effects in group-contribution methods are introduced to obtain better estimated values. The substitutions of various functional groups on aromatic rings are discriminated. Type-number corrections of the functional groups and multiple-substitution effects of halogens are also introduced; thus even heterofunctional compounds can be processed. A new concept, the quality of contribution values, is proposed to designate the qualitative reliability of the estimated physical properties. The manual procedures and tables of contribution values are given for estimating the thermodynamic properties of the compounds, as mentioned in the title, composed of C, H, O, halogens, S, and N. This method was critically compared with the Benson method in versatility and reliability.
  • Hayao Kobayashi
    1979 Volume 52 Issue 5 Pages 1315-1320
    Published: 1979
    Released: April 19, 2006
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    The resistivity measurement, DTA analysis, refinement of the crystal structure, and examination of the X-ray diffuse scattering have been carried out on the β-phase of the sodium vanadium bronze. A resistivity minimum was observed around 200 K. The peak position of the logarithmic derivative of the resistance and an anomaly in the DTA curvature indicate that a metal-insulator transition occurs at about 130 K. The X-ray diffuse scattering shows a tendency of the sodium atoms toward cluster formation. It is concluded that the β-phase of sodium vanadium bronze is neither a simple one-dimensional metal nor a simple semiconductor, but can be-have partly as a one-dimensional metal and partly as an anisotropic semiconductor.
  • Byong-Tae Chang, Li-Hye Pak, Yu-Suk Li
    1979 Volume 52 Issue 5 Pages 1321-1326
    Published: 1979
    Released: April 19, 2006
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    The solubility of diaspore (α-Al2O3·H2O or α-AlOOH) has been measured in NaOH aqueous solutions from 523.15 K to 598.15 K, and at concentrations of Na2O up to 150.7 g/l. In order to evaluate the equilibrium constant, K2°=(aAlO2·aH2O)⁄aOH, for the dissolution equilibrium of diaspore AlOOH(s)+OH(l)=AlO2(l)+H2O(l), two methods have been applied to the solubility data. In the first method, analogous to the method previously applied to the dissolution equilibria of gibbsite, bayerite and beohmite, the values of K2 at relatively low concentrations of NaOH were extrapolated to zero NaOH concentrations. The temperature dependence of K2° was expressed as logK2°=−(2500⁄T)+4.45. The second method was based on the extended Debye-Hückel theory for the variation in the activity coefficients of AlO2, OH, and H+ ions with ionic strength at any temperature, that is, the value of the solubility product, K1°=aH+·aAlO2, was obtained at a given temperature by extrapolating values of K1 equal to (mH+mAlO2), to zero ionic strength. According to the second method, K2° was expressed as a function of the temperature: logK2°=−(1600⁄T)+2.52 when A=2.0 or logK2°=−(1550⁄T)+2.48 when A=1.5, where A is a parameter. From kinetic analysis of the dissolution rate of diaspore in NaOH solution, the rate constants per unit surface area of diaspore were found to be 0.31, 0.45, and 0.68 m−2 h−1 at 548.15, 573.15, and 598.15 K, respectively.
  • Yoshihiro Taniguchi, Osamu Inoue, Keizo Suzuki
    1979 Volume 52 Issue 5 Pages 1327-1329
    Published: 1979
    Released: April 19, 2006
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    Measurements of the rates of hydrolysis of methyl, ethyl, propyl, and butyl acetates have been made to 2 kbar in water catalyzed by dodecyl hydrogensulfate (DSA) micelle at 40 °C. The rate of hydrolysis decreases with compression up to approximately 1 kbar and then increases above 1 kbar; methyl acetate differs in these respects. The inversion phenomenon under pressure has been explained by the incorporation of both the H3O+ ion and ester molecules into the micellar phase. The observed value of the over all activation volume at 1 atm ΔV* is −5.3±1 cm3/mol for methyl, 0.40±1 cm3/mol for ethyl, 9.7±1 cm3/mol for propyl, and 20±1 cm3/mol for butyl acetate, respectively. From the activation volumes of HCl and DSA micellar catalysts, the volume change accompanying the incorporation of the esters into the micellar phase ΔΔVmicelle, has been estimated to be 4.0±1 cm3/mol for methyl, 9.8±1 cm3/mol for ethyl, 18.7±1 cm3/mol for propyl, and 27.9±1 cm3/mol for butyl acetate, respectively. The values above have been explained in terms of the contribution to the hydrophobic interaction between the ester molecule and the micelle.
  • Shiro Suzuki, Tamotsu Kondo
    1979 Volume 52 Issue 5 Pages 1330-1336
    Published: 1979
    Released: April 19, 2006
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    Partially sulfonated poly(1,4-piperazinediylterephthaloyl) microcapsules were found to undergo disintegration by the action of poly(diallyldimethylammonium) ions if the polycation concentration exceeded a certain value. The polycation concentration at which disintegration started was dependent on the degree of sulfonation of the microcapsules and pH of the medium. Exact electrical equivalence of the polyions involved was shown to be a necessary condition for disintegration of the microcapsules to take place. Disintegration of the microcapsules resulted in a formation of coacervate-like liquid drops. This formation of coacervate-like liquid was accelerated by mechanical and thermal agitation. Crosslinking among the polymers constituting the microcapsules prevented disintegration from occurring.
  • Mamoru Nakanishi, Masamichi Tsuboi
    1979 Volume 52 Issue 5 Pages 1337-1339
    Published: 1979
    Released: April 19, 2006
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    When tyrosine was rapidly transferred from water into deuterium oxide medium by means of a stopped-flow device, a time-dependent change in the fluorescence intensity at 305 nm (excited at 275 nm) has been observed. The rate constant (ke) was found to be 116 s−1 at pH 5.8 and 14 °C. This ke value has been attributed to the rate constant of the O1H→O2H reaction of the phenolic OH group, on the basis of similar fluorescence examinations on phenol, anisole, glycyl-L-tyrosine, and Nα-acetyl-N-methyl-L-tyrosinamide as well as on the basis of a stopped-flow ultraviolet absorption study of tyrosine. The stopped-flow fluorometry has been applied to a study of tyrosine residues in yeast 3-phosphoglycerate kinase.
  • Yoshifumi Nishimura, Hideyuki Haruyama, Kimiko Nomura, Akiko Y. Hiraka ...
    1979 Volume 52 Issue 5 Pages 1340-1345
    Published: 1979
    Released: April 19, 2006
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    β-Uridine-5′-phosphoric acid-15N2 has been prepared from 15N-RNA of baker’s yeast which was grown in (15NH4)2SO4 as the sole nitrogen source. Its Raman spectrum has been observed both in 1H2O and 2H2O solutions. On the basis of the observed 15N isotope effects on the Raman spectra and on the basis of other data previously obtained, normal modes of vibration have been discussed for six Raman bands of the uracil residue that are considered to be in resonance with its electronic transition at 260 nm. The result has led to a conclusion that C5=C6 is longer and C4–C5 is shorter in the excited electronic state à (260 nm) than those in the ground electronic state \~{X}.
  • Shun-ichi Ishikawa, Junko Nakamura, Suehiro Iwata, Minoru Sumitani, Sa ...
    1979 Volume 52 Issue 5 Pages 1346-1350
    Published: 1979
    Released: April 19, 2006
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    The triplet-triplet absorption spectra of [2.2]paracyclophane and related cyclophanes (naphthalenophane, pyrenophane, and anthracenophane) were measured. Cyclophanes in which two component subunits fully overlap, show new bands together with monomer-like bands. The electronic structures of triplet states of these cyclophanes were studied theoretically by the “molecules in molecule” method, special attention being paid to the correlations of the electronic structures of cyclophanes with those of corresponding monomers and also to the dependences of the charge transfer interaction upon the overlapping between the component subunits and upon the molecular size.
  • Etsuro Kobayashi
    1979 Volume 52 Issue 5 Pages 1351-1358
    Published: 1979
    Released: April 19, 2006
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    In order to develop an inorganic ion exchanger for industrial use, the ion exchange behaviour of Ti(HPO4)2·0–1/2H2O with alkali metal and ammonium ions has been investigated. The ion exchange capacities of Ti(HPO4)2·1/2H2O (hemihydrate) have been determined by forward and backward titration. The saturation ion exchange capacities (QA) of the hemihydrate to Li, Na, K, Cs, and NH4 (M) ions by the forward titration method were 1.9, 3.2, 4.1, 2.5, and 3.7 meq/g at pH 4.5, respectively. The ion exchange capacities (Q°) of the hemihydrate from 0.1 M MCl were 0.31, 1.84, 2.31, 0.21, and 1.01 meq/g to each of the ions. The selectivity quotients (KHM) estimated from the QA and Q° were 0.028, 3.77, 15.7 0.008, and 0.255 to each of the ions, and the selectivities of the hemihydrate increased in the order Cs+<Li+<NH4+<Na+<K+. The empirical formula of the 50% ion exchange products derived from the hemihydrate may be represented by TiMH(PO4)2·0–1/2H2O, (where, M=Na, K, and NH4). The ion exchange of Li and Cs ions did not take place completely however to give a 50% ion exchanger, and the hemihydrate was then converted into a non-stoichiometric compound.
  • Etsuro Kobayashi
    1979 Volume 52 Issue 5 Pages 1359-1362
    Published: 1979
    Released: April 19, 2006
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    In order to develop an inorganic ion exchanger, ion exchange equilibriums between titanium(IV) bis(hydrogenphosphate) and NaCl–KCl aqueous solution have been investigated together with the possibility of separation of Na and K ions. A suitable quantity of Ti(HPO4)2·H2O (monohydrate), or Ti(HPO4)2 (anhydrate) was added to a fixed volume of the mixed solution of 0.1 M NaCl with 0.1 M KCl at various ratios. The Na and K ions in the equilibrium solution were determined, and the mole fractions of the ions distributed in the liquid and solid phases estimated. When 0.1 or 0.5 g of the monohydrate were added to 10 ml of each initial solution, the sum of the ion exchange capacities for Na and K ions was approx. 0.1–0.3 meq/g. When 0.1 g of the anhydrate were added to 10 ml of each of the initial solutions, the pH of the final solutions showed values in the range of 1.6–1.9. With the mole fractions of KCl/(NaCl+KCl) above 0.5 in the initial solution, only 2.5–3.5 meq/g of the K ion adsorbed. With an excess (0.5 g exchanger to 10 ml soln) of the anhydrate, all K ions and a part of Na ions were removed together from the solution with the mole fractions of KCl/(NaCl+KCl) being in a range of 0–0.8. The K ion could be effectively separated, when a suitable amount of the anhydrate was added to a solution containing approx. an equimole of NaCl and KCl; however, the elution of K ion with HCl could not be eased by this static method.
  • Fumio B. Ueno, Akira Nagasawa, Kazuo Saito
    1979 Volume 52 Issue 5 Pages 1363-1365
    Published: 1979
    Released: April 19, 2006
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    Tris(1,3-diphenyl-1,3-propanedionato)germanium(IV) [Ge(bzbz)3]+ was prepared as crystalline perchlorate, and resolved by the crystallization of its salt with hydrogen (R,R)-O,O-dibenzoyltartrate. The patterns of UV and circular dichroism spectra are very similar to those of [Si(bzbz)3]ClO4. The racemization of the Δ-[Ge(bzbz)3]ClO4 was studied kinetically in acetonitrile at 40–60 °C to find the rate law: Rate=krac[complex], where krac=9.86×10−5 s−1 at 50 °C. The activation parameters (ΔH\ eweq=99±2 kJ mol−1 and ΔS\ eweq=−17±2 J K−1 mol−1) are very similar to those of tris(acetylacetonato)germanium (IV) complex. Compared with the rate of ligand isotopic exchange, the racemization should proceed via intramolecular mechanism. The steric effect coming from the substituents on the chelate ring should play an important role in determining the racemization rate.
  • Takayoshi Yoshimori, Tatsuhiko Tanaka
    1979 Volume 52 Issue 5 Pages 1366-1367
    Published: 1979
    Released: April 19, 2006
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    The purity of the potassium hydrogen phthalate (NBS SRM 84d) was determined by precise coulometric titration. The purity obtained was 99.995±0.002% (standard deviation: 0.003%), and was in excellent agreement with the purities of the same SRM determined already in three laboratories in U.S.A. These results support the recommendation on the use of the Faraday constant as an international standard for titrimetric analysis.
  • Kazushi Hirota, Toshimori Sekine
    1979 Volume 52 Issue 5 Pages 1368-1371
    Published: 1979
    Released: April 19, 2006
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    Phase relations in the system PbO–PbGeO3 were determined using both the quenching and DTA techniques. Two new lead germanate phases Pb5GeO7 and Pb11Ge3O17 were found to be stable. It was found that the Pb5GeO7 melts incongruently at 738 °C to PbO plus liquid, whereas the Pb11Ge3O17 decomposes into Pb5GeO7 plus Pb3GeO5 at 728 °C. The compounds Pb3GeO5, Pb5Ge3O11, and PbGeO3 were identified as congruently melting compounds, in accordance with previous investigations. Some other compounds, such as Pb6GeO8, Pb4GeO6, and Pb3Ge2O7, which have been reported previously could not be confirmed as stable phases.
  • Katsuma Hiraki, Yayoi Obayashi, Yoko Oki
    1979 Volume 52 Issue 5 Pages 1372-1376
    Published: 1979
    Released: April 19, 2006
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    A pale yellow solution, prepared from RuCl3·3H2O and carbon monoxide in 2-methoxyethanol, reacted with 1-phenylpyrazole (Hphpz), 2-phenylpyridine (Hphpy), and benzo[h]quinoline (Hbzqn) to give new chlorobridging dinuclear cycloruthenated complexes, [{RuCl(C∼N)(CO)2}2] (C∼N=cycloruthenated moiety). These complexes reacted with Tl(acac) (acac=acetylacetonato ligand), γ-picoline (pic), and triphenylphosphine resulting in the break-down of the chloro-bridging bond of the complexes, and afforded new mononuclear cycloruthenated complexes, [Ru(acac)(C∼N)(CO)2], [RuCl(C∼N)(CO)2(pic)], and [RuCl(C∼N)(CO)n-(PPh3)3−n] (n=2 for phpz, and n=1 for phpy and bzqn), respectively. The complexes prepared in this study were characterized by IR, 1H-NMR, and mass spectroscopies.
  • Yasuji Nakayama, Shun’ichiro Ooi, Hisao Kuroya
    1979 Volume 52 Issue 5 Pages 1377-1380
    Published: 1979
    Released: April 19, 2006
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    The title compound was synthesized and characterized by means of absorption, circular dichroism, and its NMR spectra as well as X-ray structure analysis. The crystals are monoclinic, with a P21 space group, a=9.175(3), b=12.423(5), c=7.434(3) Å, β=108.1(4)°, and Z=2. The structure was determined from the diffractometcr data and refined by a least-squares method to R=0.041 for 1732 observed reflections. The Pt atom has an essentially planar coordination with 4 N atoms. The disposition of the four donor atoms is not rectangular, but trapezoidal; it is, moreover, slightly tetrahedral. The quadridentate ligand forms three 5-membered chelatc rings with the Pt atom. The two terminal rings are of a δ asymmetric envelope conformation, while the middle ring has a λ symmetric skew conformation. Both of the secondary N atoms possess a R configuration. The complex ion has a pseudo-two-fold axis by which the two terminal rings are related to each other. The circular dichroism spectrum reflects mainly the conformations of the 5-membered chelate rings. The features of the absorption and circular dichroism spectra are discussed on the basis of the geometry of the PtN4 chromophore.
  • Goro Wada, Sayuri Nakago, Yuriko Abe
    1979 Volume 52 Issue 5 Pages 1381-1385
    Published: 1979
    Released: April 19, 2006
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    The kinetics and mechanism of the electron transfer reaction between Fe(II) and Fe(III) in mixed solvents of water and hexamethylphosphoric triamide (HMPA) were studied. The apparent rate constant k varies depending upon [HMPA] and [H+]; k exhibits a minimum value at [HMPA]=1.5 M at constant [H+] and increases linearly with respect to [H+]−1 at constant [HMPA]. Judging from the basicity constant of HMPA, the complex formation constant of Fe(hmpa)3+, and the absorption spectra of aqueous solutions containing Fe(II), Fe(III), HMPA, and HClO4, the existing species in the reaction systems are mostly Fe2+aq, Fe3+aq, Fe(OH)2+, Fe(hmpa)3+, and Fe(hmpa)(OH)2+ at low concentrations of HMPA. Therefore, the probable reaction paths are Fe2+–Fe3+, (k0); Fe2+–Fe(OH)2+, (kH); Fe2+–Fe(hmpa)3+, (kL); and Fe2+–Fe(hmpa)(OH)2+, (kHL) at the concentration range of [HMPA]=0–1 M and [HClO4]=0.03–0.2 M. The occurrence of a minimum value of k vs. [HMPA] is reasonably understood by taking the complex formation between Fe(III) and HMPA into account in reaction rate equation. If the hydrolysis constants of both Fe(OH)2+ and Fe(hmpa)(OH)2+ are considered to be nearly of the same order, the value of kH are approximately ten times larger than that of kHL. At higher concentrations of HMPA, the higher Fe(III)-complexes with HMPA might take part in the electron transfer reaction.
  • Mitsuo Abe
    1979 Volume 52 Issue 5 Pages 1386-1390
    Published: 1979
    Released: April 19, 2006
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    A stoichiometrical ion-exchange was observed for all the systems of Mg2+, Ca2+, Sr2+, and Ba2+ with H+ in the crystalline antimonic(V) acid as a cation exchanger. The selectivity sequence, Mg2+<Ba2+<Sr2+<Ca2+, has been found for the ion-exchange reactions in 0.1 M nitrate salt solutions of different alkaline earth metals. Breakthrough and further elution studies were carried out in order to test the reversibility of the ion-exchange reactions. X-Ray analysis indicates that a solid solution forms for the ion-exchange system of the alkaline earth metal ions in the crystalline antimonic(V) acid.
  • Kenichi Okazaki, Muraji Shibata
    1979 Volume 52 Issue 5 Pages 1391-1401
    Published: 1979
    Released: April 19, 2006
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    Complexes of the [Co(amOH)(N)2(O)2]-type, where amOH represents 2-aminoethanol or (S)-2-amino-1-propanol and (N)2(O)2 represents (gly)2, (β-ala)2, (ox)(en) or (ox)(NH3)2, have been prepared and characterized on the basis of absorption and PMR spectra. Splitting of the T2g band has been observed in the solution spectra of certain isomers of the [Co(gly)2(eta)], [Co(gly)2(S-pra)], or [Co(β-ala)2(eta)] complex. Using the crystal spectral data of the isomers of [Co(gly)2(eta)], the σ- and π-antibonding parameters for the ligating alcoholate O atom have been estimated and it has been found that each parameter shows a higher value than the corresponding parameters for the other ligating N and O atoms. The CD spectrum, in the T2g region, of fac-[Co(gly)2(eta)] has shown an intense peak at ca. 25000 cm−1, and the vicinal effect curve of each isomer of the [Co(gly)2(S-pra)] complex has shown an intense peak at the same frequency.
  • Haruo Sato, Takeshi Tominaga
    1979 Volume 52 Issue 5 Pages 1402-1407
    Published: 1979
    Released: April 19, 2006
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    The photolytic reactions of bis- and tris-oxalato iron(III) complexes in a solid, solutions, and frozen solutions were studied by means of 57Fe Mössbauer spectroscopy. An iron(II) species was observed as a metastable intermediate product in the photolysis of tris(oxalato) ferrate(III) in a solid and solutions. A mechanism with a sequence of iron(II) intermediates was tentatively proposed for the photolysis and subsequent reactions in this compound. The Mössbauer technique was also used to examine whether or not tris(oxalato)ferrate(III) was diluted uniformly with diamagnetic substances in the mixed crystals and frozen solutions.
  • Hideaki Kanno, Kazuo Kashiwabara, Junnosuke Fujita
    1979 Volume 52 Issue 5 Pages 1408-1412
    Published: 1979
    Released: April 19, 2006
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    A new ligand, (R)- and (S)-3,3′-dimethyl-2,2′-bipyridyl N,N-dioxide(mbdo) forms three diastereomers(I, II, and III) of [Cr(mbdo)3]3+ by the reaction with [Cr(H2O)6]3+ in water. (I) was assigned to a pair of enantiomers, Δ(RRR) and Λ(SSS), and (II) and (III) to either a diastereomeric pair of Δ(RRS) and Λ(SSR) or Δ(SSR) and Λ(RRS). While the racemic (I) was resolved by SP-Sephadex column chromatography, (II) and (III) isomerized in water to each other (II\ ightleftarrowsIII) by exposure to ultraviolet light, were resolved by the reaction of [Cr(H2O)4(R or S)-mbdo]3+ with a stoichiometric amount of (S or R)-mbdo. The circular dichroism spectra of these optically active isomers were measured in aqueous solutions and compared with those of complexes of the [CrO6]-type of known absolute configuration. The optically active free (+)589- and (−)589-mbdo were isolated by decomposing Λ(SSS)- and Λ(RRR)-[Cr(mbdo)3]3+, respectively, with edta4−. The active mbdo is optically stable even in boiling water.
  • Isamu Kinoshita, Kazuo Kashiwabara, Junnosuke Fujita, Takashi Yamane, ...
    1979 Volume 52 Issue 5 Pages 1413-1419
    Published: 1979
    Released: April 19, 2006
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    (S)-2-(Butylphenylphosphinomethyl)pyrrolidine(L) was prepared from (S)-proline via four main reaction steps. A pair of diastereomers of the PdCl2L complex, the isomerism of which comes from chiral configuration of the phosphorus atom, crystallized in different forms (needle and block), which were separated by hand picking. The molecular structure and absolute configuration of one(block) of the dichloro complexes was determined by X-ray analysis. Crystallographic data are: P212121, Z=4, a=13.576(4), b=16.351(3), c=8.041(2) Å, and R=7.8% for 1659 reflections. The Pd atom has a distorted square planar coordination of four donor atoms. The Pd-Cl bond distance trans to Pd-P, 2.367 Å, is longer than that trans to Pd–N, 2.296 Å. The absolute configuration of the coordinated phosphorus atom was determined to be R by assuming S configuration for the asymmetric carbon atom of the aminophosphine. The corresponding diastereomers of the dibromo complex were also prepared from each diastereomer of the chloro complex. The circular dichroism spectra of these diastereomers were compared with one another and with those of other related complexes, and the vicinal effects due to the chiral phosphorus atoms in these complexes were examined.
  • Akira Fuyuhiro, Kazuaki Yamanari, Yoichi Shimura
    1979 Volume 52 Issue 5 Pages 1420-1422
    Published: 1979
    Released: April 19, 2006
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    The determination of solubility isotherm of a ternary system, Λ-[Co(ox)(en)2](d-C10H14OBrSO3)–Δ-[Co(ox)(en)2](d-C10H14OBrSO3)–H2O, between 5 and 25 °C, revealed that the resolving agent (1R,3S,4S,7R)-3-bromocamphor-9-sulfonate ion is applicable to the optical resolution of the [Co(ox)(en)2]+ ion below 19 °C from the viewpoint of solubility in water, in spite of the formation of a pseudo racemic compound, Λ-[Co(ox)(en)2Δ-[Co(ox)(en)2] (d-C10H14OBrSO3)2·2H2O.
  • Nobuo Mori, Shin-ichi Kasuya, Hitoshi Miyazaki, Toshiyuki Takezawa
    1979 Volume 52 Issue 5 Pages 1423-1426
    Published: 1979
    Released: April 19, 2006
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    The various values vOH of 1,2-benzocycloalken-3-ols observed in dilute CCl4 solutions have been explained in terms of the inclination angle of the C–O bond to the plane of the benzene ring (θ) and the conformational isomerism of the OH group with respect to the C–O bond. The vOH shift caused by OH…π bonding is angle-dependent, i.e., 9 cm−1 if θ=50–90°, or 17 cm−1 if θ=38–45°.
  • Hideo Tsutsumi, Kimio Inoue, Yoshiharu Ishido
    1979 Volume 52 Issue 5 Pages 1427-1430
    Published: 1979
    Released: April 19, 2006
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    The reaction of 1,3-diphenyl-1,3-propanedione (1) with 2-chloroethanol (2) or 3-chloro-1-propanol (3) was performed in the presence of potassium carbonate and sodium iodide as an improved procedure for regioselective C-hydroxyalkylation, involving intramolecular alcoholysis; the effects of the solvents, the temperature, and the amounts of potassium carbonate and sodium iodide were also investigated. The reaction with 2 afforded 3-benzoylpropyl benzoate (4) (ca. 70% yield), together with 2-benzoylmethyl-2-phenyl-1,3-dioxolane (5) (ca. 15% yield). The reaction with 3, on the other hand, gave 4-benzoylbutyl benzoate (92–94% yield); the corresponding 1,3-dioxane derivative was detected only in a trace. Moreover, the reaction of 1 with 2-hydroxyethyl tosylate was similarly performed, but the yields of both 4 and 5 were unexpectedly low.
  • Shigeru Ikeda, Fumio Tonegawa, Etsuro Shikano, Kozo Shinozaki, Masaaki ...
    1979 Volume 52 Issue 5 Pages 1431-1436
    Published: 1979
    Released: April 19, 2006
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    The preparation and purification of diphenylphosphinothioyl(Ppt)-amino acids were studied. The side-chain functional groups of tyrosine and cysteine were found to react also with diphenylphosphinothioyl chloride to form O-Ppt and S-Ppt derivatives. Acidic reagents for the removal of N-Ppt group were examined by using N,O-bis-Ppt-tyrosine ethyl ester (III) as the most difficult model, HCl in HCO2H–CH2Cl2 being found to be most preferable. The O- and S-Ppt bonds were stable during the course of acidic treatments, but could be removed by alkaline hydrolysis. An application of Ppt-amino acids to the solid phase peptide synthesis is given.
  • Masaru Kimura, Shiro Morosawa
    1979 Volume 52 Issue 5 Pages 1437-1440
    Published: 1979
    Released: April 19, 2006
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    3-Ethoxycarbonyl-1,2,3,4,5,10-hexahydroindeno[1,2-d]azepine (10b) was synthesized from 1-benzylpiperidin-4-one and 1-benzyl-4-[o-(hydroxymethyl)phenyl]hexahydroazepin-4-ol. Compound 10b is of particular interest as an intermediate for the preparation of the hitherto unknown indeno[1,2-d]azepine. It was found that 1-ethoxycarbonyl-4-[o-(hydroxymethyl)phenyl]hexahydroazepin-4-ol and 1-ethoxycarbonyl-4-[o-(hydroxymethyl)phenyl]piperidin-4-ol (16b) give 1-ethoxycarbonylspiro[azepin-4,1′(3H)-isobenzofuran] and 1-ethoxycarbonylspiro[3H-isobenzofuran-1,4′-piperidine] (17b), respectively. Treatment of 16b with 88% formic acid gave 17b and 2-ethoxycarbonyl-2,3,4,9-tetrahydro-1H-indeno[2,1-c]pyridine.
  • Jun-ichi Hayami, Tohru Koyanagi, Aritsune Kaji
    1979 Volume 52 Issue 5 Pages 1441-1446
    Published: 1979
    Released: April 19, 2006
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    Chlorine isotopic exchange reactions of substituted chloromethanes [(arylsulfonyl)chloromethanes (1), (arylsulfinyl)chloromethanes (2), and 2-chloro-1-arylethanones (4)] with tetraethylammonium chloride-36Cl were studied in acetonitrile. This study enabled, for the first time, the accurate rate study of the former two classes of compounds (1 and 2) of extremely low reactivity. Both the large enthalpies of activation and the positive entropies of activation were the characteristics for these two substrates (1-p-NO2 and 2-p-NO2). High reactivity of 2-chloro-1-phenylethanone was substantiated, and was not associated with the significant secondary kinetic deuterium isotope effect. A nucleophile-substrate association that proceeds the reaction was suggested and the possible role of such an interaction was examined in the light of the intermediary of the nucleophile-substrate complex in the Finkelstein reaction.
  • Takao Kimura, Masahiro Minabe, Kazuo Suzuki
    1979 Volume 52 Issue 5 Pages 1447-1449
    Published: 1979
    Released: April 19, 2006
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    The compound 9-(4H-cyclopenta[def]phenanthren-4-yl)-9,9′-bifluorene was synthesized by the Michael addition of 4H-cyclopenta[def]phenanthrene to 9,9′-bifluorenylidene and also by other reactions. In addition, five kinds of trimers which consisted of 4H-cyclopenta[def]phenanthrene and fluorene were obtained by the same reactions. The conformation of these trimers is assigned to be the gauche-gauche form.
  • Takashi Matsumoto, Akira Suetsugu
    1979 Volume 52 Issue 5 Pages 1450-1453
    Published: 1979
    Released: April 19, 2006
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    The Grignard reaction of 7-methoxyphthalide with methylmagnesium iodide, followed by acetylation and dehydration, gave 3-acetoxymethyl-2-isopropenylanisole which, on catalytic hydrogenation, afforded 3-acetoxymethyl-2-isopropylanisole. This was then converted into (2-isopropyl-3-methoxybenzyl)triphenylphosphonium chloride (8) via 3-hydroxymethyl-2-isopropylanisole and 3-chloromethyl-2-isopropylanisole. The Wittig reaction of (R)-(−)-α-cyclocitral with 8 in the presence of butyllithium afforded the corresponding styryl derivative, which was converted into the dihydro compound (19) by partial catalytic hydrogenation. The intramolecular cyclization of 19 gave (+)-totaryl methyl ether (20) along with its cis-isomer. The methyl ether 20 was finally demethylated with boron tribromide to give (+)-totarol (1), which was further characterized as its acetate. Since the conversion of (+)-1 into (+)-podototarin has already been reported, the present work can be regarded as the total synthesis of natural (+)-podototarin.
  • Mamoru Ai, Atsumu Ozaki
    1979 Volume 52 Issue 5 Pages 1454-1458
    Published: 1979
    Released: April 19, 2006
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    The outstanding property of the SnO2–MoO3 catalyst in the oxidation of propylene to acetone was confirmed by tests of various oxide catalysts supported on pumice. The optimum composition was found to be SnO2-70/MoO3-30 mol % for the oxidation at from 170 to 260 °C. It was also found that this pumice-supported catalyst is sufficiently selective for the acetone formation even at a high temperature of 260 °C, and that it gives a high yield of acetone while keeping its high selectivity. The selectivity increases up to 90 mol % with an increase in the partial pressure of water vapor and with a decrease in the oxygen partial pressure. On the basis of such information, it can be said that a high yield of acetone can be obtained by the divided introduction of oxygen.
  • Takashi Matsumoto, Shogo Harada
    1979 Volume 52 Issue 5 Pages 1459-1463
    Published: 1979
    Released: April 19, 2006
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    Methylation of 12-benzoyloxyabieta-8,11,13-trien-11-ol with methyl iodide afforded 11-benzoyloxy-12-methoxyabieta- and 12-benzoyloxy-11-methoxyabieta-8,11,13-triene (9). Oxidation of the latter product with chromium trioxide, followed by sodium borohydride reduction and acetylation, gave 7β-acetoxy-12-benzoyloxy-11-methoxyabieta-8,11,13-triene (17) and its 7α-acetoxy isomer (18) in a ratio of ca. 5 : 1. On the other hand, treatment of 9 with lead tetraacetate produced 17 and 18 in a ratio oi ca. 1 : 2. The 7β-acetate (17) was then oxidized with chromium trioxide and the resulting p-quinone derivative was hydrolyzed with aqueous sodium hydroxide to give taxoquinone (1), which on dehydration gave dehydroroyleanone. Similarly, the 7α-acetate (18) was converted into horminone (4) via the p-quinone derivative, which was treated with aqueous sodium hydrogencarbonate to give 7α-acetoxyroyleanone. Oxidation of 4 with manganese dioxide afforded 7-oxoroyleanone. Methylation of 1 with diazomethane, followed by oxidation with a chromium trioxide-pyridine complex, afforded 12-methoxyabieta-8,12-diene-7,11,14-trione, which on reduction with sodium dithionite gave inuroyleanol.
  • Ryoichi Yoshida, Tadashi Yoshida, Yasuko Ikawa, Takeshi Okutani, Yasuk ...
    1979 Volume 52 Issue 5 Pages 1464-1467
    Published: 1979
    Released: April 19, 2006
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    Solvent extracts of Athabasca tar sand were analyzed by the Brown-Ladner method, the Takeya et al. method, and the Speight method on the basis of the 1H-NMR data and by 13C-NMR spectroscopy. The structural characteristics of Athabasca tar sand derivatives were also compared with those of coal-hydrogenolysis products. The results show that the structural characteristics of hexane solubles, monomers consisting of one aromatic ring substituted highly with C6 aliphatic chains, resemble those of the oil fraction produced during the initial stage of the hydrogenolysis of Taiheiyo coal. However, the structural characteristics of the hexane insoluble-benzene solubles, oligomers consisting of 2 aromatic rings substituted highly with C4–5 aliphatic chains, are different from those of any coal-hydrogenolysis products. In addition, the close agreement between the fa value obtained by the Brown-Ladner method and 13C-NMR may indicate that, for solvent extracts of Athabasca tar sand, the assumption in the Brown-Ladner method that the atomic H/C ratio of aliphatic structures is 2 is proper.
  • Akira Tai, Hiroshi Watanabe, Tadao Harada
    1979 Volume 52 Issue 5 Pages 1468-1472
    Published: 1979
    Released: April 19, 2006
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    The hydrogenation of methyl 2-methyl-3-oxobutyrate (I) to methyl 3-hydroxy-2-methylbutyrate (III) was carried out with various types of asymmetrically modified nickel catalysts (MNi). The use of MNi always resulted in the deviation of the ratio, 2S/2R=((2S,3R)-III+(2S,3S)-III)/((2R,3R)-III+(2R,3S)-III, from 1/1, in spite of the use of racemic I. A catalyst giving a larger 2S/2R value always gave a larger 3R/3S value. These results led to the conclusion that the configurations at the C-2 and C-3 positions of the product were determined in the process of the formation of the complex between the substrate and the modifying reagent (the absorption step), not at the step of the hydrogen addition to the adsorbed substrate (the rate-determining step). The best optical yield and the highest ratio of erythro-III/threo-III were obtained when (R,R)-tartaric acid-MNi was used as a catalyst. The amounts of the isomers produced were in the following order: 2S,3R>>2R,3R≈2R,3S>2S,3S. Stereochemical models are proposed to account for the formation of the 2S,3R-isomer in a large excess.
  • Yoshiro Ogata, Atsushi Kawasaki, Yasuhiko Sawaki, Yuya Yamauchi
    1979 Volume 52 Issue 5 Pages 1473-1477
    Published: 1979
    Released: April 19, 2006
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    The kinetics of the reaction of α-chloro aliphatic acids (CAA’s) with aqueous ammonia to form the corresponding α-amino acids and α-hydroxy acids have been studied by measuring the produced chloride ion. The observed rate for CAA’s having COOH on a s-C (s-CAA’s) is expressed as: v=(k1+k2[NH3]ex)[CAA], while the rate for CAA having COOH on a t-C (t-CAA): v=k1[CAA], These results together with previous observations indicate that the mechanism changes with substrate, i.e., pure SN2 type for chloroacetic acid to pure SN1 type for α-chloroisobutyric acid. The exclusion of α-lactone mechanism and the effect of carboxylato group are discussed. The reactivity of ammonia toward α-chloro aliphatic acids is as twice as that of hydroxide ion.
  • Seiki Saito, Kenji Doihara, Toshio Moriwake, Kunio Okamoto
    1979 Volume 52 Issue 5 Pages 1478-1487
    Published: 1979
    Released: April 19, 2006
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    Solvolysis of a series of ring substituted threo-1-methyl-2-phenylpropyl brosylates has been carried out in N,N-dimethylacetamide (DMA) as solvent. Hammett treatment of the rate data indicated that the DMA solvolysis of the unsubstituted brosylate (1c) falls into the category of ks pathway (100%). In order to gain further information of the nature of the ks pathway, the DMA solvolysis of 1c or 1c-2-d (labeled at C(2)) has been conducted. The product distribution, effect of water content on it, the composition and deuterium distribution of recovered brosylate, kinetic isotope effect, and the deuterium distribution of product have been investigated. The products consisted of the olefins ((E)- and (Z)-2-pheny1-2-butenes, and 2- and 3-phenyl-1-butenes), and, in the presence of water in DMA, the carboxylates (erythro- and thero-1-methyl-2-phenylpropyl acetates) and the small amount of diastereomeric alcohols. The major product was (Z)-2-phenyl-2-butene, indicating the occurrence of anti-E1 process. The deuterium was substantially scrambled in each product. These findings suggest that the reaction proceeds through tight ion-pair and subsequent processes such as anti-E1, 2,1-phenyl and -hydride shifts, solvent capture, and threo-erythro interconversion take place competitively. In view of a substantial extent of intervention of such rearrangement, the involvement of nucleophilic solvent assistance is thought to be less probable in this ks process.
  • Kazutoshi Funahashi
    1979 Volume 52 Issue 5 Pages 1488-1492
    Published: 1979
    Released: April 19, 2006
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    Oxiranes reacted with aryl esters in the presence of base. The reactions of aryl carboxylates with alkyloxiranes afforded almost exclusively 1-alkyl-2-(aryloxy) ethyl carboxylates, whereas the reactions with aryloxiranes gave a mixture of 1-aryl-2-(aryloxy) ethyl carboxylates and 2-aryl-2-(aryloxy) ethyl carboxylates. Similar results were also obtained in the reaction with S-aryl thiocarboxylates and diaryl carbonates. The rate of reaction between phenyl acetate and phenoxymethyloxirane (PMO) in the presence of tributylamine (n-Bu3N) as a catalyst has been determined in the temperature range 110 to 130 °C and may be expressed by –d[PMO]⁄dt=k2[n-Bu3N]·[PMO]. The apparent activation energy calculated from the Arrhenius plots is 85.8 kj/mol. The reaction catalyzed by tributylamine is assumed to proceed through zwitter ions, n-Bu3\overset+NCH2CH(R)O and n-Bu3\overset+NCH(R)CH2O, which attack aryl carboxylate.
  • Kiyoshi Kikukawa, Makoto Takagi, Tsutomu Matsuda
    1979 Volume 52 Issue 5 Pages 1493-1497
    Published: 1979
    Released: April 19, 2006
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    Reaction of triphenylphosphine with an equimolar amount of Pd(OAc)2 in acetic acid at room temperature in the presence of styrene gave trans-stilbene(94%), H3PO4(0.8%), PhP(O)(OH)2(40%), Ph2P(O)(OH)(19%), and Ph3P=O(35%). Reactions of tributyl- and trioctylphosphine with Pd(OAc)2 in acetic acid at 90 °C yielded butene(20%) and octene(1-; 22%, 2-; 17%), respectively, as main products. The phenylation of some olefins with triphenylphosphine in acetic acid-d, as well as other features of the reaction lead to the conclusion that nucleophilic attack on coordinated phosphorus atom is the most probable pathway for the formation of the phenylation agent (phenylpalladium species) in the reaction system among the others, ortho-metallation and oxidative addition.
  • Minoru Hirota, Hideyuki Masuda, Yoshiki Hamada, Isao Takeuchi
    1979 Volume 52 Issue 5 Pages 1498-1505
    Published: 1979
    Released: April 19, 2006
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    Nucleophilic substitution reactions of monoaza- and diaza-naphthalenes and -phenanthrenes were discussed on the basis of an HMO calculation taking the nature of the reagent into consideration. Results were compared with the orientation of some nucleophilic substitution reactions, i.e. Chichibabin amination, phenylation by phenyllithium, and methylation by methylsulfinylmethanide ion. The nature of the reagent was explicitly taken into account as the difference in the coulomb integrals and the reagent-dependent orientation of these reactions were explained theoretically.
  • Takeshi Imagawa, Tsunefumi Nakagawa, Mituyosi Kawanisi, Keiiti Sisido
    1979 Volume 52 Issue 5 Pages 1506-1510
    Published: 1979
    Released: April 19, 2006
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    Thermal reaction of coumalic acid with 1,3-butadienes gave after diazomethane treatment dimethyl tricyclo[3.2.1.02,7]oct-3-ene-2,4-dicarboxylate via double Diels-Alder reaction. This represents the simplest synthesis of such a tricyclic system. The reaction with cyclopentadiene was also studied.
  • Yasuo Nakada, Rokuro Endo, Shigeki Muramatsu, Junya Ide, Yasuo Yura
    1979 Volume 52 Issue 5 Pages 1511-1514
    Published: 1979
    Released: April 19, 2006
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    A new method is described for the stereoselective synthesis of trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-1-cyclopropanecarboxylic acid (2t) via ethyl 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate (3a) as a key intermediate. The key intermediate (3a) was obtained by addition of carbon tetrachloride to ethyl 3,3-dimethyl-4-pentenoate, prepared by condensation of 3-methyl-2-buten-1-ol and triethyl orthoacetate followed by Claisen rearrangement. Treatment of 3a with sodium t-pentyloxide in benzene gave ethyl trans-2,2-dimethyl-3-(2,2,2-trichloroethyl)-1-cyclopropanecarboxylate (6t) in good yield. Dehydrochlorination and hydrolysis of 6t using potassium hydroxide in ethanol afforded 2t in high yield.
  • Tetsuo Otsubo, Masashi Kitasawa, Soichi Misumi
    1979 Volume 52 Issue 5 Pages 1515-1520
    Published: 1979
    Released: April 19, 2006
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    A simple synthetic method of [3.3]cyclophanes via dithia[4.4]cyclophanes is presented. The spectra of a variety of cyclophanes were examined and compared to those of [2.2]analogues. It was concluded from the absorption spectra that the transannular π-π interactions of the cyclophanes were strongly dependent on both ring-to-ring distance and overlapping mode. From the emission spectra, it was described that cyclophanes of parallel sandwich type formed easily normal excimers, whereas [2.2]metacyclophane and [2.2]- and [3.3]metaparacyclo-phanes formed strained excimers showing marked red shifts of fluorescence bands.
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