Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 41 , Issue 10
Showing 1-50 articles out of 80 articles from the selected issue
  • Seigo Ohno, Iwao Yasumori
    1968 Volume 41 Issue 10 Pages 2227-2233
    Published: 1968
    Released: March 27, 2006
    JOURNALS FREE ACCESS
    Kinetic studies of the catalytic ortho-parahydrogen conversion and hydrogen-deuterium equilibration on highly purified γ-alumina were conducted in the range of temperature from 77 to 221°K and in the range of pressure from 10 to 120 mmHg. The rate equation obtained can be well explained by a mechanism which involves the reaction between an adsorbed atom and a molecule. The true activation energy, E, and the heat of adsorption of the reactive molecule, Q, were estimated as E=0.51–0.80 and Q=0.51–0.72 kcal/mol for the conversion (77–95°K), and E=4.6 and Q=1.9 kcal/mol for the equilibration (145–221°K). The conversion at temperatures below 90°K was found to proceed mostly via the magnetic mechanism. A thermal desorption study of adsorbed ethylene showed that there are three types of adsorption on γ-alumina with different activation energies of desorption, and that these species occupy a total of only a few hundredths of the surface. It was concluded that the most strongly-adsorbed ethylene blocks the reactions via the chemical mechanism, while the most weakly-adsorbed one retards the conversion via the magnetic mechanism. The nature of active sites for the reactions was discussed by taking the results of the ESR measurement into consideration.
  • Yoshimi Kurimura, Ryoji Ochiai, Niro Matsuura
    1968 Volume 41 Issue 10 Pages 2234-2239
    Published: 1968
    Released: March 27, 2006
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    The oxidation of ferrous ions by dissolved oxygen in aqueous solutions in the presence of such chelating agents as EDTA, DTPA, EDTAOH, EDTP, CyDTA and NTA was studied spectrophotometrically. The rate equation for the oxidation reaction is:
    d[Fe^III]/dt=4k_p[Fe^IIHZ][O_2]+4k_n[Fe^IIZ][O_2]
    where kp is the rate constant for the (1) reaction; kn, the rate constant for the (2) reaction; FeIIHZ, protonated chelate, and FeIIZ, the normal chelate.
    &Fe^IIHZ+O_2\xrightarrowk_pFe^IIIZ+HO_2 \labeleq1
    &Fe^IIZ+O_2\xrightarrowk_nFe^IIIZ+O_2^-\labeleq2
    The linear relationship between log k and log Rf shown by Eq. (3), was obtained from all the experimental results except for those on the EDTPA and CyDTA systems:
    logk=0.92+0.13logR_f\labeleq3
    In Eq. (3), k is 4kp and Rf is KFeIIILKFeIIHL, for the protonated chelate, while k is 4kn and Rf is KFeIIILKFeIIL for the normal chelate. In the cases of the DTPA and CyDTA systems, a deviation from the straight line was observed. This can be explained by steric hindrance of the oxygen attack by these chelates.
  • Tsutomu Kagiya, Y\={u}z\={o} Sumida, Tetsuya Nakata
    1968 Volume 41 Issue 10 Pages 2239-2247
    Published: 1968
    Released: March 27, 2006
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    The elementary processes constituting the polymerization reaction are energetically considered, and the relation between the activation energy of each process and the structures of reagents or the kind of solvents is theoretically discussed. The solvation energy of ion has been evaluated with the ionization potential of anion or the electron affinity of cation, and the ionization potential or the electron affinity of the growing radical with that of the corresponding monomer. The energy of the highest occupied (εho=α+λhoβ) or the lowest vacant (εlv=α–ηlvβ) π level of the monomer has been calculated, and the π bond dissociation energy has been evaluated with the summation (λholv). On the basis of these considerations, the monomer reactivity in catalytic polymerization can be compared with the relative magnitude of the electronic natures of monomer and components of catalyst, i. e., ionization potential or electron affinity.
  • Tsutomu Kagiya, Y\={u}z\={o} Sumida, Tetsuya Nakata
    1968 Volume 41 Issue 10 Pages 2247-2253
    Published: 1968
    Released: March 27, 2006
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    According to the theoretical conclusion reported previously on the activation energy of the catalytic polymerization, the experimental results relating to the monomer reactivity and the catalytic activity in anionic or cationic polymerization were interpreted. The catalytic activity in ionic polymerization can be quantitatively compared with the relative magnitude of the ionization potential or the electron affinity of monomer and components (A, D) of catalyst (AD). As a measure of the ionization potential or the electron affinity of monomer, the energy of the highest occupied (εho=α+λhoβ) or the lowest vacant (εlv=α−ηlvβ) π level of the monomer has been used, and as a measure of the electron affinity of component D, the pKa of the acid HD or the σ1 value. In anionic polymerization, it was found that the polymerization by the catalyst with the same component A took place only in the combination of the monomer and the catalyst in which the ηlv/pKa value was less than about 2.5×10−2, and that the catalytic activity, with the same component D, depends on the kind of solvent. The results in cationic polymerization were also discussed in connection with the electron affinity of component D or co-catalyst. And the monomer reactivity in ionic polymerization with the same catalyst was quantitatively discussed with the ηlv or λho value of monomer. From the accordance between the theoretical consideration and the experimental data, the present treatment was found to be useful for the purpose of the quantitative study of the catalytic activity and the monomer reactivity in ionic polymerization.
  • Kichisuke Nishimoto, Leslie S. Forster
    1968 Volume 41 Issue 10 Pages 2254-2257
    Published: 1968
    Released: March 27, 2006
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    The interrelationships between the semi-empirical parameters involved in SCFMO calculations have been considered. The calculated transition energies for molecules containing an atom that donates two electrons to the π-system are mainly dependent upon the first valence state ionization energy of the heteroatom, and the nearest-neighbor two center repulsion integrals.
  • Toshiro Yamashina, Takaaki Nagamatsuya, Masakatsu Sano
    1968 Volume 41 Issue 10 Pages 2257-2263
    Published: 1968
    Released: March 27, 2006
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    The nature of the active sites of nickel oxide has been studied by changing surface properties by means of γ-irradiation technique. Using powdered nickel oxide catalyst, catalytic activities, surface excess oxygen contents, electrical conductivity changes during thermal desorption of gases, and reactivities of the sample with CO2, CO and H2 were compared as a function of γ-ray dose of preirradiation. It has been found that the catalytic activity, the excess oxygen content and the conductivity change with the increase in the irradiation dose, and the change is remarkable when a total dose is greater than 1×108R. The catalytic activity for the decomposition of H2O2 was observed to increase, while that for the decomposition of i-C3H7OH vapor was observed to decrease with the irradiation dose. Measurements on the desorption of excess oxygen and the adsorption of CO2 simultaneously with electrical conductivity have indicated that the adsorbed state of surface oxygen may be changed into a strong form by the irradiation, as O(ad) \ ightsquigarrow O2−(ad). Discussions have been made on the correlation between the catalytic sites and surface properties of the irradiated nickel oxide.
  • Isao Ohno, Kaoru Iguchi
    1968 Volume 41 Issue 10 Pages 2264-2269
    Published: 1968
    Released: March 27, 2006
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    UV and visible absorption spectra of monohalogenated anthracenes are measured, and the first absorption band are reported. When anthracene is monohalogenated, the first absorption band slightly shifts toward red or does not shift in accordance with the change in the position and the species of the substituting halogen atom, but the vibrational structure remains unchanged. The sequence of magnitude of red shift due to the position is 9-halo>1-halo>2-halo-anthracene, while that due to the species is different depending on the substituted position: in the 9-position, it is monobromo>monochloro>monofluoro>monoiodo anthracene, and, in the 1 or 2-position, it is monochloro>monofluoro>monobromo\simeqmonoiodo anthracene. For the sequence of red shift due to the species of the substituting halogen atom, there are similarities between the first absorption band of monohalogenated anthracenes and the K or B-band of monohalogenated benzenes. These results are discussed in terms of the simple LCAO MO perturbation treatment.
  • Hirotake Kamei
    1968 Volume 41 Issue 10 Pages 2269-2273
    Published: 1968
    Released: March 27, 2006
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    The nitrogen-14 quadrupole relaxation broadening effect on the proton spectrum of formamide was eliminated by a 1H–{14N} double resonance technique. The completely-decoupled proton spectra of formamide in the neat liquid and in acetone, dioxane, and water solutions were observed at several temperatures. The spectra observed at room temperature were analyzed on the basis of an ABC system, while the spectra at higher temperatures (∼100°C) were analyzed on the basis of an AB2 system. From the changes in the resonance lines of the formyl proton with the temperature, the values of the activation energy for the hindered internal rotation about the C–N bond, Earot, and for the intermolecular proton exchange involving the amine protons, Eaex, were obtained. It has been found that the hydrogen-bond formation on the carbonyl oxygen of formamide increases the Earot value and the magnitude of the vicinal coupling constants, while it decreases the magnitude of the geminal coupling constant.
  • Michio Okuda, Takeo Kowata, Yoshiharu Usui, Masao Koizumi
    1968 Volume 41 Issue 10 Pages 2274-2280
    Published: 1968
    Released: March 27, 2006
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    The ESR signals of polycrystalline methylene blue (MB) salts have been investigated in respect to a) temperature effect, b) anion effect, c) influence of the addition of donor and acceptor and d) response to visible light irradiation, a) The signal intensity in general increases with the rising temperature, but a sharp difference in the ESR behavior has been found above and below room temperature. Response to the temperature change at low temperature is reversible and the apparent activation energy is ca. 0.03 eV (L-type behavior) whereas the high temperature behavior has a marked tendency of irreversibility and the activation energy is at least one order larger (H-type behavior), b) No essential anion effect has been observed on g-value, line shape and spin concentration for chloride, iodide and phosphate, c) The addition of trinitrobenzene and paraphenylenediamine in 10 : 1 to MB chloride also had no essential effect, d) Corresponding to the L-type and H-type behavior observed in a), visible light irradiation has been found to cause a decrease or an increase in signal intensity respectively at low and high temperature. From these findings it has been concluded that there are at least two kinds of defect (L-type and H-type) and that the formation of radical species occurs only on such defect sites. Some suggestions have been made on the nature of these two types of defects and on the molecular processes occurring at or near these defect sites. The radical formation reaction is most likely to be connected with dyedye interaction, D++D+\ ightleftharpoonsD+++D.
  • Shigeru Tsunashima, Shin Sato
    1968 Volume 41 Issue 10 Pages 2281-2284
    Published: 1968
    Released: March 27, 2006
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    The reactions of acetylene photosensitized by Cd(3P1) have been investigated at 270±1°C. The main products were benzene and vinylacetylene. The formations of polymer and hydrogen were not observed. From the studies of the effects of pressures and foreign gases on the quantum yields, the product formations were successfully explained by the reactions of excited molecules. The investigation of the reaction of a mixture of hydrogen and acetylene photosensitized by Cd(3P1) suggests that benzene is also formed from the reactions of hydrogen atoms and acetylene molecules.
  • Fumikatsu Tokiwa, Kenji Ohki, Isao Kokubo
    1968 Volume 41 Issue 10 Pages 2285-2288
    Published: 1968
    Released: March 27, 2006
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    An attempt has been made to apply gel filtration on Sephadex to micellar solutions of surfactants. The data on the gel filtration of surfactants were interpreted by taking into account the fact that there exist both micellized and unmicellized species in the solutions. A simple method for obtaining the retention volume of the micelle (VM) of a surfactant directly from the elution curve was developed. Further, the relation between the values of VM and the micellar molecular weights (MMW) was examined for various types of surfactants. A linear relation was found between VM and log MMW, with the exception of a surfactant with a heterocyclic structure. It appears that gel filtration offers a convenient way for roughly estimating the MMW’s of surfactants.
  • Nobuyuki Tanaka, Setsuko Yamamoto, Yuichi Sato
    1968 Volume 41 Issue 10 Pages 2288-2292
    Published: 1968
    Released: March 27, 2006
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    The electrode process of ethylenediaminetetraacetatocobaltate(II) (CoIIY2−) at the dropping mercury electrode has been studied in the presence of iodide ions. It was found that polarographic anodic waves of CoIIY2− were affected by the film of mercury(I) iodide which was formed electrolytically at the electrode surface. The measurement of current-time curves during the life of a mercury drop and the coulometric studies revealed that the electro-oxidation of CoIIY2− was completely inhibited by the formation of monomolecular layer of mercury(I) iodide on the mercury surface.
  • Akira Yokohata, Katsuyuki Harakon, Satoru Tsuda
    1968 Volume 41 Issue 10 Pages 2292-2297
    Published: 1968
    Released: March 27, 2006
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    In order to elucidate the effects of discharge gap distance and discharge current on SGH2O2, SGOH and SGH, the study of this series was further made by using a new discharge apparatus. Both of acidic aqueous solutions of ferrous sulfate and ferrous sulfate-cupric sulfate have been selected as the reaction systems suitable for this purpose. Experiments were made in the range from 3 mm to 9 mm of discharge gap distance and from 0.2 mA to 0.5 mA of discharge current. Each SG value of H2O2, OH and H varied with gap distance (5→9 mm) and current (0.2→0.5 mA) as follows; in the former, 1.0→1.2, 1.8→0.9 and 1.1→0.9: in the latter, 1.4→1.2, 0.6→0.9, 0.8→0.9. Based on the value of Y(H2O2)/Y(H+OH), it was concluded that (1) the silent discharge reactions under a longer gap distance correspond to the radiolysis having a value of higher LET, that (2) although those under a lower current do also to a higher one, the effect of discharge current on the value of apparent LET is relatively small.
  • Teijiro Yonezawa, Isao Morishima, Kazuhiko Fukuta
    1968 Volume 41 Issue 10 Pages 2297-2305
    Published: 1968
    Released: March 27, 2006
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    The variations in the chemical shifts of proton resonances in imines, aziridines, and oximes, all of which have oriented nitrogen lone-pair electrons, on going from a carbon tetrachloride solution to a benzene solution (“benzene solvent shift”) are determined. Also determined are the changes in the corresponding proton chemical shifts in a benzene solution when protic substances, such as methanol or trifluoroacetic acid, are added (“addition shift”). It is generally found that the upfield benzene-solvent shift is more sensitive to the protons trans to the oriented nitrogen lone-pair than to the cis. This observation indicates that the formation of a benzene-solute collisional complex is most likely to occur at a site as far as possible from the nitrogen lone-pair. The repelling of a benzene solvent molecule by the nitrogen lone-pair may occur due to the repulsive interaction between lone-pair electrons and benzene π-electrons. It is also found that the addition shift is upfield and is larger for the proton trans to the nitrogen lone-pair than for that cis. These general observations are of predictive value in the determination of the orientation of the nitrogen lone-pair electrons and in the assignment of the signals of proton groups in the vicinity of the nitrogen lone-pair.
  • Hideaki Konishi, Tamaichi Ashida, Masao Kakudo
    1968 Volume 41 Issue 10 Pages 2305-2311
    Published: 1968
    Released: March 27, 2006
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    The crystal structure of cysteic acid, C3H7NO5S, has been determined. The crystal is orthorhombic with a space group of P212121, and four molecules are in a unit cell with these dimensions: a=8.35, b=10.16, and c=7.44 Å. The molecule is a zwitter ion, O3SCH2CH-(NH3+)COOH; its dimensions are generally similar to those found in other amino acids and sulfonic acids. The acidic groups occupy the trans positions with respect to the Cα–Cβ bond, while the amino group is in a gauche position to the sulfonic group and forms an intramolecular hydrogen bond between them.
  • Hiroshi Yamashita, Hiroshi Kokubun, Masao Koizumi
    1968 Volume 41 Issue 10 Pages 2312-2319
    Published: 1968
    Released: March 27, 2006
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    It has been established by the flash photolysis that the N,N-dimethyl β-naphthylamine (DMN) cation is produced by the interaction of excited DMN with dimethyl isophthalate (DMP). The assignment has been made by comparing the transient spectrum with that obtained by the γ-radiolysis of DMN in s-butyl chloride. The decay of the DMN cation is first order in acetone (DK, 20.7), ethanol (24.3) DMF (36.7), second order in formamide (109.5) and it is the superposition of first and second order in acetonitrile. This strongly suggests that the radical cation exists as the solvent-shared ion pair in medium polar solvents while as free species in highly polar solvents. The decay of the former has been found to be not essentially affected by oxygen. The finding that the transient spectrum is observed even in the aerated solution supports the view that it is produced at the singlet excited state. From the effect of [DMP] on the yield of triplet DMN, it has been inferred that the radiationless process occurring in the ex-CT complex is mainly internal conversion. The reactivity of the triplet DMN against DMP has been found very small as compared with that of the signlet excited state; the rate constant for (DMN)T+DMP→DMN+DMP was k10\simeq105 M−1 sec−1. The erroneous discussion given in the previous paper has been corrected; the decrease both in the quenching constant (for normal fluorescence) and in the emissivity of the ex-CT emission with the solvent polarity (in slightly polar solvents) is most likely to be attributed to the solvent-solute interaction, the increase of which (with the increase in solvent polarity) is unfavorable both to the formation of the ex-CT complex and to the emissivity of the ex-CT emission.
  • Hiroshi Masuhara, Michio Okuda, Masao Koizumi
    1968 Volume 41 Issue 10 Pages 2319-2324
    Published: 1968
    Released: March 27, 2006
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    Electronic absorption spectra of two types of half reduced acridine, i. e., C-radical (unpaired electron on 9-C-atom) and N-radical (unpaired electron on N-atom), of half-reduced anthracene and of xanthene deprived of one hydrogen atom, are measured in several rigid solvents at 77°K. It has been established that these radicals can be produced conveniently by irradiating the rigid solutions of the reduced forms, by a medium high pressure mercury lamp. It has been found that the absorption spectra of these radical species are generally classified into three groups, a) ∼250 nm (4.9 eV), b) ∼350 nm (3.5 eV) and c) visible (2.3–2.8 eV). Peculiar features for each radical species are; i) anthracene radical has no visible absorption, ii) acridine N-radical has no absorption at ∼250 nm, and iii) acridine C-radical has a prominent sharp peak at 281 nm. Flash photolytic and ESR studies have also been performed on the radical species produced upon irradiation of dihydroanthracene and xanthene; the results obtained have substantiated the assignment of the intermediates observed in rigid solvents.
  • Kuniyoshi Shimizu, Yoshiaki Yoshida, Manabu Sen\={o}, Hiroshi Nozaki
    1968 Volume 41 Issue 10 Pages 2325-2330
    Published: 1968
    Released: March 27, 2006
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    The rectifying properties of the combined systems of two crystals, one being doped with a proton donor (poly(styrene sulfonic acid) or hydrogen fluoride) and the other being doped with a proton acceptor (poly(2-vinyl-N-n-butylpyridinium bromide), poly(2-vinyl-N-n-butylpyridinium hydroxide) or lithium hydroxide) are examined and discussed. In the case of the combination of the ices doped with poly(styrene sulfonic acid) and poly(2-vinyl-N-n-butylpyridinium hydroxide) or poly(2-vinyl-N-n-butylpyridinium bromide), the current versus voltage curves have the hysteresis loops and the rectification ratio defined as the ratio of the forward current to the backward current is low. The dynamic rectification effect is slightly observed. In the case of the combination of the ices doped with lithium hydroxide and hydrogen fluoride, the rectification ratios exceed 100 and the rectification mechanism is presumed to be the same as in the system of the aqueous solutions. The dynamic characteristics depend on the frequencies; the rectification phenomena are not observed when the alternating voltages with frequencies higher than 30 kc are applied.
  • Mitsuo Abe, Kuniaki Sakato, Takashi Kageyama, Masaaki Fukatsu, Michio ...
    1968 Volume 41 Issue 10 Pages 2330-2336
    Published: 1968
    Released: March 27, 2006
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    The sedimentation behavior of anionically polymerized poly (α-methyl styrene) has been studied as a function of molecular weight, concentration and speed of centrifugation under the theta condition of solvent and temperature, i. e., in cyclohexane at 39°C. Analysis of the data was made by use of Fujita’s equation for the pressure- and concentration-dependent sedimentation. It was found that the sedimentation coefficient at zero concentration and one atmosphere was given as s00=2.00×10−15 M1⁄2 sec, where M is molecular weight. The concentration dependence coefficient k and the pressure dependence coefficient p appearing in the Fujita equation were obtained as k=6.2×10−4 M1⁄2 dl/g, and μ=1.6×10−9 cm2/dyne, respectively. The intrinsic viscosity in the theta solvent was also determined as [η]θ=7.60×10−4 M1⁄2 dl/g.
  • Teijiro Yonezawa, Kiyoshi Simizu, Hiroshi Kato
    1968 Volume 41 Issue 10 Pages 2336-2342
    Published: 1968
    Released: March 27, 2006
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    The electronic structures of bicyclo(1.1.0)butane, tricyclo(3.1.0.0)hexane, tricyclo(2.1.0.0)pentane, tricyclo(1.1.0.0)butane, prismane, and spiro(2.2)pentane are studied by the extended Huckel method. The calculated total energies of bicyclo(1.1.0) butanes with various dihedral angles, θ, and bridgehead C–C–H angles, α, show that the most stable configuration of bicyclo-butane is at α=135° and θ=115–120°. It is made clear that the s-nature of the carbon atoms of the C–Haxial and C–Hequatorial depends greatly on the dihedral angle of the two cyclopropane rings. The double-bond character between the bridgehead carbon atoms in the bicyclobutane and its homologues is pointed out. The stabilities of the C–C bonds of prismane are shown to be largely dependent on the angle between the C–H bond and the four-membered-ring plane. The electronic structures of some configurations of spiropentane with different dihedral angles are discussed. The physico-chemical properties of these compounds are briefly investigated.
  • Haruo Shizuka, Ikuzo Tanaka
    1968 Volume 41 Issue 10 Pages 2343-2349
    Published: 1968
    Released: March 27, 2006
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    The photochemical rearrangement of acetanilide under 2537 Å irradiation has been studied by spectrophotometry. The quantum yield of the rearrangement in cyclohexane solution was independent of the irradiation time, concentration of acetanilide, presence of oxygen and light intensity. It was found that electronic energy transfer from the electronically excited benzene to acetanilide occurred in the mixed solution, and the transfer mechanism was explained by singlet-singlet nonradiative energy transfer. It was observed that the energy transfer rate constant was about 22 times greater than that predicted by diffusion theory (the transfer rate constant, k3=1.45×1011 l·mol−1·sec−1). From these studies, it is proposed that the rearrangement of acetanilide is an introamolecular reaction and does not occur from the triplet state but from the lowest singlet excited state.
  • Yonezo Morino, Kozo Kuchitsu, Yasur\={o} Hori, Mitsutoshi Tanimoto
    1968 Volume 41 Issue 10 Pages 2349-2352
    Published: 1968
    Released: March 27, 2006
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    The internuclear distances of cyanogen were determined by gas electron diffraction to be rg(C≡N)=1.1634±0.0019 Å and rg(C–C)=1.3925±0.0022 Å. The average moment of inertia calculated from this structure agreed with Maki’s infrared results as corrected for rotation-vibration interaction. The spectroscopic moment of inertia obtained by Maki was used for calibrating the electron-diffraction scale factor, and the zero-point average distances, with their limits of error, were obtained as rz(C≡N)=1.1552±0.0013 Å and rz(C–C)=1.3871±0.0014 Å.
  • Masako Suzuki, Takehiko Shimanouchi
    1968 Volume 41 Issue 10 Pages 2353-2356
    Published: 1968
    Released: March 27, 2006
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    Succinonitrile silver nitrate [Ag(NCCH2CH2CN)]NO3 and succinonitrile disilver nitrate [Ag(NCCH2CH2CN)Ag](NO3)2 were prepared and the infrared spectra down to 60 cm−1 were measured. It was shown that the ligand molecule takes only the trans form in these complexes. The far infrared spectra were also measured for the free succinonitrile ligand at room and liquid nitrogen temperatures and for the copper complex. The assignments of bands for the nitrate ion and the trans and the gauche forms of succinonitrile were given.
  • Hisaya Oki, Eishin Kyuno, Ryokichi Tsuchiya
    1968 Volume 41 Issue 10 Pages 2357-2361
    Published: 1968
    Released: March 27, 2006
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    Cobalt(II) tetraisothiocyanatochromate(III), Co[Cr(NCS)4(NH3)2]2, was prepared from cobalt(II) chloride and Reinecke’s salt in an aqueous solution. The absorption spectrum gave evidence that the so-called “cobalt-salt” dissociated into cobalt(II) cation and Reineck’s anion in aqueous solution. The reflection spectrum showed a remarkably strong absorption band at 14.08×1013 sec−1, which might be assigned to bonding between cobalt(II) and sulfur in an NCS ligand. The three absorption peaks observed at 2158, 2095 and 2065 cm−1 in the IR spectrum due to C–N stretching vibrations also emphasized the strong interaction between cobalt and sulfur. The effective magnetic moment estimated was 4.58 B. M. at 18.3°C. The corresponding copper(II) salt, Cu(OH)[Cr(NCS)4(NH3)2], was obtained from an aqueous solution of copper(II) sulfate and Reinecke’s salt as a yellow powder. It was a sparingly soluble in water. In the reflection spectrum, the red-shifted band covered much of the first band region of Reinecke’s salt and in the IR spectrum, the C–N band had only a small splitting. The magnetic moment was found to be 3.84 B. M. at 16.0°C, which is close to the predicted value in the complex when copper is reduced, becoming univalent. X-Ray diffraction analysis also showed a relatively stronger contraction of the unit cell in the copper salt than in the cobalt salt. On the basis of the above points, it was proposed that in the copper salt there is considerable π-bonding between copper and the two adjacent isothiocyanate groups.
  • Hisaya Oki, Eishin Kyuno, Ryokichi Tsuchiya
    1968 Volume 41 Issue 10 Pages 2362-2366
    Published: 1968
    Released: March 27, 2006
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    Nickel (II), manganese (II) and black iron(III)-tetraisothiocyanatochromate(III) were prepared by the reaction of nickel(II) nitrate, manganese (II) sulfate and iron(III) chloride with Reinecke’s salt, respectively. Each salt exhibits a gradual color change from reddish-purple to brownish-orange, red and black, respectively, when exposed to dry air after preparation, except for the orange iron(III) salt prepared in hydrochloric acid solution, which shows no color change from the original orange. Their absorption spectra give evidence that each salt will dissociate into a metal cation and Reinecke’s anion in aqueous solution. Splittings due to the C–N stretching vibration were not observed in the IR spectra. The effective magnetic moments were evaluated as 3.96, 5.13, 5.0 and 4.81 B. M. for the nickel(II)-, the manganese (II)-, the black iron(III)- and the orange iron(III)-salts, respectively. They show that the salts are nearly low spin types, or a type somewhere between low and high spin. From X-ray diffraction analyses, the unit cell of all the salts were found to be tetragonal.
  • Mitsuo Abe, Takuji Ito
    1968 Volume 41 Issue 10 Pages 2366-2371
    Published: 1968
    Released: March 27, 2006
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    The cation-exchange behaviour and surface functionality of three different antimonic acids, amorphous, glassy and crystalline, were studied by thermogravimetric measurement, infrared absorption spectrometry and change in uptake of potassium ions upon heating. The ion-exchange capacities of the amorphous and glassy antimonic acids decrease with the loss of chemically bonded water. In contrast, the capacities of the crystalline acid heated within 200°C rarely change because of the loss of the interstitial (free) water and no drastic change occurs in the surface structure of the crystal. The crystalline acid with free water removed adsorbs moisture upon exposure to the atomsphere at room temperature. Upon heating above 300°C, the tenaciously bonded water was removed and the cation-exchange capacity decreased simultaneously. The infrared absorption spectra indicated that the surface functionality of the crystalline acid, similar to that of crystalline sodium antimonate Na[Sb(OH)6], is different from those of the amorphous and glassy acids. It seems that chemically bonded water in the crystalline acid is tenaciously combined as Sb-OH.
  • Mutsuo Kodama, Mitsuko Murata, Tomohiko Noda, Akiko Kimura
    1968 Volume 41 Issue 10 Pages 2371-2375
    Published: 1968
    Released: March 27, 2006
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    This paper will present two results of experiments concerning the adsorption of brucine. We will first discuss the adsorption of brucine on D. M. E. studied tensammetrically. Brucine was found to give a tensammetric wave with two peaks, at +0.10 V and −1.15 V vs. SCE. The positive tensammetric peak can be ascribed to the usual adsorption process. The second peak, however, behaved differently from the first, probably due to the reformation of adsorbed brucine film involving the protonation and the reorientation of brucine. Secondly, we will present experimental facts concerning the depressive effects of brucine on the reduction waves of copper(II).
  • Nobuyuki Tanaka, Masaru Kimura
    1968 Volume 41 Issue 10 Pages 2375-2378
    Published: 1968
    Released: March 27, 2006
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    The kinetic study of the substitution reaction of copper(II) ions and zinc(II)-nitrilotriacetate complexes in acetate buffer solutions has been carried out with the same procedure as reported previously. The reaction was treated as to proceed through both hydrated metal ions and monoacetato complexes. The rate constants for eight elementary reaction paths, of which four involve the hydrated copper(II) ions and the others the monoacetatocopper(II) complexes, were determined at ionic strength 0.23 at 0°C. The values obtained indicate that all the reactions proceeding through hydrated copper(II) ions are faster than the corresponding reactions proceeding through monoacetatocopper(II) complexes.
  • Keshawa Chandra Pathak
    1968 Volume 41 Issue 10 Pages 2379-2381
    Published: 1968
    Released: March 27, 2006
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    Ammonium telluro-tungstomolybdate 6(NH4)2O·2TeO3·WO3·10MoO3·30H2O and the corresponding salts with silver, strontium, barium, cerium, lead, iron and guanidine have been isolated, their properties studied and the composition determined by the analytical methods. IR spectra of ammonium and guanidine salts have been recorded and the characteristic peaks assigned. Thermal decomposition studies (TGA and DTA) of ammonium salt were made. Differential thermal analysis of ammonium salt was done in nitrogen atmosphere too.
  • Jiro Kashima, Takuo Yamazaki
    1968 Volume 41 Issue 10 Pages 2382-2384
    Published: 1968
    Released: March 27, 2006
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    The inert gas extraction-gas chromatographic technique has been applied for the determination of hydrogen in ferrous metals. As this method was dependent on gas chromatography, the simplification was performed on the apparatus and the analytical operation. A procedure was evolved, according to which the extracged hydrogen was measured by means of gas chromatography using the precolumn technique, viz., (1) the hydrogen was rapidly transferred from the metal into an argon stream by means of H-F induction furnace, (2) this was concentrated into the cold precolumn for 4 min to collect the total amount of hydrogen from the extraction tube, (3) this was measured by gas chromatography. Analytical results obtained on 3 iron base metals suggest that the method can be widely used for the determination of hydrogen in ferrous metals.
  • Akira Uehara, Eishin Kyuno, Ryokichi Tsuchiya
    1968 Volume 41 Issue 10 Pages 2385-2392
    Published: 1968
    Released: March 27, 2006
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    Ammoniapropionicdiacetic acid (APDA), which belongs to a group of chelating agents similar to that of ammoniatriacetic acid, was prepared. The newly-prepared complexes containing this chelating agent were as follows: [Cr(OH)(apdaH)(H2O)2] (red purple) (I), NH4[Cr(OH)(apda)(H2O)]·2H2O (purple) (II), (NH4)3[Cr(apda)2]·2H2O (pink) (III), (Cr(apda)-(bipy)]·3H2O (brown) (IV), [Cr(apda)(o-phen)]·3H2O (brown) (V), and [Cr(apda)(py)2](pink) (VI), where apda, bipy, o-phen, and py are the abbreviations of the ammoniapropionate-diacetate ion, o-phenanthroline, 2,2′-bipyridyl, and pyridine respectively. On the basis of the chemical and thermal analyses, and on the basis of the measurements of the visible, UV, reflection and IR spectra and molar conductivities, it was concluded that the ammoniapropionatediacetate acts either as a terdentate or a quadridentate ligand in these complexes. Unlike the ATA complex, no complexes in which the nitrogen dose not coordinate with chromium could be prepared in the case of APDA. The values of the effective magnetic moments for these APDA complexes were nearly equal to the spin-only values of tervalent chromium. Further comparisons of the properties of the APDA complexes with those of the ATA complexes were also made.
  • Akira Uehara, Eishin Kyuno, Ryokichi Tsuchiya
    1968 Volume 41 Issue 10 Pages 2393-2400
    Published: 1968
    Released: March 27, 2006
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    A new chelating agent—ammoniaisopropionicdiacetic acid (abbreviated as AIPDA), one of the derivatives of ammoniatriacetic acid, was prepared. Also, the following chromium(III) complexes containing AIPDA as a ligand were newly prepared: NH4[Cr(OH)(aipda)(H2O)]·4H2O (purple) (I), NH4[Cr(OH)(aipda)(H2O)2]·2H2O (green) (II), [Cr(aipda)(o-phen)]·2H2O (brown) (III), [Cr(aipda)(bipy)]·3H2O (brown) (IV), [Cr(aipda)(l-pn)] (pink) (V), [Cr(aipda)-(py)2] (Pink) (VI) and NH4[Cr(OH)(aipda)(py)]·2H2O (reddish purple) (VII), where apipda, o-phen, bipy, l-pn and py are the abbreviations of the ammoniaisopropionatediacetate ion, o-phenanthroline, 2,2′-bipyridyl, l-propylenediamine and pyridine respectively. On the basis of the chemical and thermal analyses and the measurements of the electronic absorption spectra, the reflection spectra, and the IR spectra, it was found that, in these complexes, AIPDA can behave as a terdentate or a quadridentate ligand to chromium(III), but the 1 : 2 Cr(III) AIPDA complex like the corresponding ATA one could not be obtained because of the steric hindrance resulting from the introduction of a methyl group into ATA. Further information on the conductivities in an aqueous solution and the reflection spectra suggests that V and VI are gradually aquated. The properties of the AIPDA complexes obtained in the present study were compared with those of ammoniatriacetic acid and those of ammoniapropionicdiacetic acid complexes.
  • Mutsuo Kodama, Tomohiko Noda
    1968 Volume 41 Issue 10 Pages 2401-2405
    Published: 1968
    Released: March 27, 2006
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    The use of a hanging mercury drop electrode (HMDE) in the a.c. polarographic determination of thallium was studied systematically. Analysis was carried out by scanning anodically the potential of HMDE from the limiting-current potential region at a constant scanning rate and by measuring the a.c. peak-height for the anodic stripping process of thallium. Thallium could be concentrated effectively on the HMDE at the initial stage of this procedure and then stripped anodically. By employing this technique, a marked increase in sensitivity could be obtained and 1.0×10−6 M thallium(I) in an EDTA solution was determined accurately. The interference effects of lead, cadmium, zinc, and indium on the determination of thallium were also investigated. When the electrolysis was initiated in the limiting-current potential region of lead(II), the peak-height of thallium was found to be enhanced markedly.
  • Mutsuo Kodama, Mitsuko Murata
    1968 Volume 41 Issue 10 Pages 2405-2410
    Published: 1968
    Released: March 27, 2006
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    The a.c. polarographic determination of lanthanum(III), nickel(II), calcium (II), and magnesium(II) with diethylenetriaminepentaacetic acid was studied by using a dropping mercury electrode and a hanging mercury drop electrode as indicator electrodes. Lanthanum(III) and nickel(II) in an acetate buffer solution and calcium(II) and magnesium(II) in an ammonia buffer solution could be titrated with diethylenetriaminepentaacetic acid in the concentration range from 5×10−5 to 1×10−3 M by measuring the height of the a.c. polarographic wave of diethylenetriaminepentaacetic acid after the end point. The effect of the presence of calcium-(II) ions on the a.c. polarographic determination of lanthanum(III) in an acetate buffer solution of pH 4.0 was also examined and discussed thermodynamically.
  • Hiroshi Ogino, Nobuyuki Tanaka
    1968 Volume 41 Issue 10 Pages 2411-2416
    Published: 1968
    Released: March 27, 2006
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    The rate of the electron-transfer reactions between ethylenediaminetetraacetatochromate(II) and some acidopentaamminechromium(III), CrX(NH3)52+, has been measured at ionic strength 1.0 (NaClO4). The rate constants (l mol−1sec−1) for X=F, Cl, Br and OH are 2.07 at 25°C, >2×103 at 25°C, 2×103 at 15°C and 2.4×102 at 25°C, respectively. These reactions produce ethylenediaminetetraacetatochromate(III) ions which do not contain an anion X. The mechanisms of these reactions are discussed.
  • Shichiro Takata, Eishin Kyuno, Ryokichi Tsuchiya
    1968 Volume 41 Issue 10 Pages 2416-2418
    Published: 1968
    Released: March 27, 2006
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    Formation constants of chromium(III) complexes with β-alanine, anthranilic acid, picolinic acid and 8-hydroxyquinoline, being all (N, O)-type bidentate chelate ligands, were determined by the pH method at an ionic strength μ=0.1, and at 25°C. The formation constants are log k1=9.69 for β-alanine, log k1=4.35 and log k2=3.67 for anthranilic acid, log k1=4.76, log k2=4.38 and log k3=4.55 for picolinic acid and log k2=9.76 and log k2=8.48 for 8-hydroxyquinoline, respectively. The relationships between the formation constants of the complexes and the acid dissociation constants of the chelate ligands were discussed, including those for glycine and α-alanine complexes, and those, in addition, for the complexes with several (N, N)- and (O, O)-type ligands reported in a preceding paper.
  • Atsushi Manome, Kazuo Saito
    1968 Volume 41 Issue 10 Pages 2419-2421
    Published: 1968
    Released: March 27, 2006
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    Concentration equilibrium constants of benzoyl-thiobenzoylmethane (SdbmH) complexes of bivalent magnesium, cobalt, nickel, copper and zinc have been measured in 75% (v/v) aqueous dioxane containing 0.05 M sodium perchlorate. The values for the transition metal ions are greater than those of dibenzoylmethane (dbmH) complexes measured under the same conditions, although the pK value of SdbmH is smaller than that of dbmH. Contribution of dπ–dπ interaction seems to be responsible for such an unusual relationship.
  • Kousaburo Ohashi, Junnosuke Fujita, Bun-e Shimoyama, Kazuo Saito
    1968 Volume 41 Issue 10 Pages 2422-2427
    Published: 1968
    Released: March 27, 2006
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    Seven new optically active complexes of fac-Δ- and fac-Λ-[Co2(L-armoH)3(L-amo)3]3+ type have been prepared, where L-amoH and L-amo denote L-aminoalcohol and L-aminoalcoholate ion, respectively. The geometrical and the absolute configuration around the metal ion of these complexes have been determined on the basis of their absorption and circular dichroism (CD) spectra. The complexes are monomeric tervalent complex ions in acid solution. In organic solvents and in crystalline states, they seem to have a dimeric structure with face-to-face O···H···O hydrogen bonds between three OH groups of the triprotonated [Co(L-amoH)3]3+ and three oxygen atoms of the deprotonated [Go(L-amo)3]0.
  • Yoshinaga Oka, Toyoaki Kato, Hui-Tuh Tsai
    1968 Volume 41 Issue 10 Pages 2427-2430
    Published: 1968
    Released: March 27, 2006
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    An internal-monitor method proposed previously has been applied to the determination of trace amounts of antimony in tin by activation with thermal neutrons. After the antimony activity is chemically separated from the irradiated sample, the γ-ray spectrum corresponding to a mixture of 124Sb and 125Sb formed by the β decay of 125m,125Sn is measured. Synthetic mixtures of antimony and tin with known weight ratios have been prepared to check the accuracy of the method. Good proportionality has been obtained between the ratios of the 124Sb to 125Sb activities and the ratios of the concentrations. By using this relationship, antimony analysis can easily be carried out. The content of antimony in a sample of tin down to 0.2 ppm can be determined with a relative error of ±2%.
  • Hisao Yamamoto, Toshio Atsumi
    1968 Volume 41 Issue 10 Pages 2431-2434
    Published: 1968
    Released: March 27, 2006
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    The cyclization reaction of cyclohexanone acetylphenylhydrazone to produce a tetrahydrocarbazole derivative has been reinvestigated. Although other workers obtained only a deacylated derivative in the reaction products, we found also an acylated product. It can be concluded from the experimental results that an acyl group of the N1-position of a phenylhydrazine derivative participates only a little in the indole cyclization and that the deacetylation occurs mainly after formation of a new C–C bond.
  • Akira Misono, Tetsuo Osa, Takamasa Asano, Takeo Suzuki
    1968 Volume 41 Issue 10 Pages 2434-2439
    Published: 1968
    Released: March 27, 2006
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    The reaction of a mixture of β-chloropropionitrile, acrylonitrile, and water with a sodium amalgam was investigated. The main product was adiponitrile, which was formed mainly via a route consisting of three steps: I. The replacement of the chloride of β-chloropropionitrile with sodium. II. The addition of the organometallic intermediate formed to acrylonitrile. III. The replacement of the sodium in the final intermediate with hydrogen. The amount formed through the Wurtz reaction was small. The by-products were propionitrile, acrylonitrile, polymers of acrylonitrile, and organometallic compounds. The details of this reaction are given in this paper.
  • Tadashi Sasaki, Fujinao Matsunaga
    1968 Volume 41 Issue 10 Pages 2440-2442
    Published: 1968
    Released: March 27, 2006
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    [CoX(DH)2·P-4VP] (X: CN, Cl)-type polymeric complexes were prepared from dimethylglyoxime (DH2) and poly-4-vinylpyridine (P-4VP) by a procedure similar to that reported for the preparation of [CoX(DH)2·Pyr] (Pyr: pyridine) (T. Sasaki and F. Matsunaga, submitted to Bull. Chem. Soc. Japan). Moreover, their catalytic activities in the decomposition reaction of hydrogen peroxide were compared with those of the corresponding monomeric complexes [CoX(DH)2·Pyr]; it was found that their activities decreases in the following order:
    [CoCl(DH)_2·P-4VP]>[CoCl(DH)_2·Pyr]>>[CoCN(DH)_2·P-4VP]>[CoCN(DH)_2·Pyr]
    About the relationship between structure and activity, it was concluded that the activity is much influenced by the nature of the X ligand of cobaloximes. It increases with a decrease in the interaction between the cobalt and nitrogen of a pyridine ring and with a weakening in the basicity of the coordinated bases. The structures of the polymeric complexes are discussed on the basis of their spectral data.
  • Go Hata, Akihisa Miyake
    1968 Volume 41 Issue 10 Pages 2443-2446
    Published: 1968
    Released: March 27, 2006
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    The admixture of cobalt chloride, (RO)nPCl3−n(n=0–3), and triethylaluminum catalyzes the codimerization of 1,3-dienes with ethylene to give exclusively cis isomers of 1,4-dienes, which result from the 1,4-addition of a C–H bond of ethylene to the 1,3-dienes. The addition of ethylene to methyl-substituted 1,3-dienes occurs predominantly on the substituted sides of the 1,3-dienes. The activity of the catalyst is strongly affected by the nature of the trivalent phosphorus components.
  • Akira Misono, Tetsuo Osa, Yoshitomo Sanami
    1968 Volume 41 Issue 10 Pages 2447-2453
    Published: 1968
    Released: March 27, 2006
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    The gas-phase dehydration of tetrahydropyran-2-methanol (TPM), prepared by the hydrogenation of the acrolein thermal dimer (3,4-dihyro-2H-pyran-2-carboxaldehyde (AD)), was investigated over various catalysts under atmospheric pressure. In this reaction, some of the pyran ring was found to be rearranged rapidly to a seven- or five-membered ring. For example, the highly-purified and crystalline η-alumina without any carrier produced cyclopentanecarboxaldehyde (GPA) as the main product in the yield of 71% at 330°C. Over the commercial alumina catalyst, considerable amounts of 2,3,4,5-tetrahydrooxepine (THO) and oxepane (OXP) were produced as by-products, though CPA was the main product; in some cases, as much THO and OXP were produced as CPA. On the other hand, the use of a dehydrogenation catalyst resulted in THO as the main product and CPA as a by-product; in the case of the use of copper-chromium oxide supported on Kieselguhr, with hydrogen as a carrier gas at 430°C, the yields of THO and CPA were 44.8% and 4.7% respectively. In these skeletal rearrangements, the seven-membered carbonium ion compound produced by the Wagner-Meerwein-type rearrangement must be a reaction intermediate. From this intermediate, mainly CPA was produced over alumina, influencing the lone-electron pair of the ethereal oxygen. THO, on the contrary, was produced mainly over a dehydrogenation catalyst. Moreover, twice as high a yield of 1,6-hexanediol was obtained from the hydrogenation of the hydrated THO than from the hydrogenolysis of TPM or AD, as has been noted in a previous paper.
  • Tadashi Sasaki, Shoji Eguchi
    1968 Volume 41 Issue 10 Pages 2453-2457
    Published: 1968
    Released: March 27, 2006
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    Acetoxylation of O-acetylisophotosantonic lactone (I) and its isodihydro derivative (III) with lead tetraacetate was reinvestigated. The reaction of III in refluxing benzene afforded the known 2-acetoxy derivative (V) as the main product and α-diketone as the minor product which was isolated in its 2-keto-3-ol form (VII). The use of boron trifluoride- etherate as a catalyst in this acetoxylation, however, did not give good results. The ORD curves of dihydro-O-acetylisophotosantonic lactone (II), III, 2-bromo-isodihydro-O-acetylisophotosantonic lactone (IV), V and one of the hydrogenolysis product of I (X) were measured and some stereochemical problems of these compounds were discussed.
  • Tadashi Masamune, Masaji Ohno, Ken Takemura, Shigehiro Ohuchi
    1968 Volume 41 Issue 10 Pages 2458-2465
    Published: 1968
    Released: March 27, 2006
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    The configurations of three stereoisomers, α, β and γ, of perhydroacridine and those, α, β and γ, of perhydrophenanthridine have been assigned as trans,syn,trans, trans,anti,cis, trans,syn,cis, trans,anti,trans, trans,syn,cis and cis,syn,cis, respectively, on the basis of both the process of their syntheses and the rate of formation of methiodides of the N-methyl derivatives. These configurations are consistent with the infrared-spectral behavior of their N-methyl derivatives in carbon tetrachloride solutions containing n-butanol as well as with the result of their exhaustive methylations. The relative steric requirement of the lone pair and the hydrogen on the N atom is also discussed.
  • Tadashi Masamune, Mitsuo Takasugi, Minoru Matsuki
    1968 Volume 41 Issue 10 Pages 2466-2472
    Published: 1968
    Released: March 27, 2006
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    The infrared spectra of stereoisomers of several piperidines and their N-methyl derivatives in carbon tetrachloride have been measured in the region of 3020 to 2500 cm−1. The estimated intensities (A) of their Bohlmann bands have been analyzed, provided that Formula (1) concerning the intensity defined in the text holds for the compounds examined. The result indicates that piperidine exists mainly, but not exclusively, in the conformation with the lone pair axial.
  • Tsutomu Kagiya, Tomizo Kondo, Kenichi Fukui
    1968 Volume 41 Issue 10 Pages 2473-2479
    Published: 1968
    Released: March 27, 2006
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    The polymerization of N-phenylethylenimine was carried out using various carboxylic acid catalysts (pKa=0.23–4.87) in acetonitrile at 0°C. The number-average molecular weight was determined by measuring the allyl-group content in the infrared spectrum of the polymer initiated with allylformate. The relationship between the number-average molecular weight and the reduced viscosity was determined. Both the conversion and the number-average molecular weight increased with the reaction time when weak acid (pKa=2.85–4.87) was used. On the other hand, when strong acid (pKa=0.23–2.85) was used, conversion reached a limited value which increased in proportion to the amount of the catalyst. With the strong acid, the efficiency factor of the catalyst was almost unity, and was independent of the reaction time. On the other hand, with the weak acid, it was smaller than unity and increased proportionally with the amounts of the polymer formed. The rate constants of the elementary reactions were evaluated on the basis of the kinetic study. The rates of the initiation, propagation, and termination reaction increased with a decrease in the pKa of the acid. With a weak acid, the termination reaction is slow at a low temperature (below 50°C), and increases with the reaction temperature, whereas with a strong acid the termination reaction occurs markedly even at a low temperature (above 0°C), and increases slightly with the temperature. The mechanism of the termination reaction was discussed on the basis of a structural study of the end group of the polymer.
  • Tetsuo Kato, Nobuo Mitsuyasu, Michinori Waki, Satoru Makisumi, Nobuo I ...
    1968 Volume 41 Issue 10 Pages 2480-2483
    Published: 1968
    Released: March 27, 2006
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    A protected heptapeptide corresponding to sequence 24–30 of ribonuclease T1, namely benzyloxycarbonyl-O-benzyl-L-tyrosyl-L-glutaminyl-L-leucyl-L-histidyl-γ-t-butyl-L-glutamyl-β-t-butyl-L-aspartyl-glycine ethyl ester (XI), was synthesized by coupling of benzyloxycarbonyl-O-benzyl-L-tyrosyl-L-glutaminyl-L-leucine azide with a tetrapeptide ester, L-histidyl-γ-t-butyl-L-glutamyl-β-t-butyl-L-aspartyl-glycine ethyl ester, which is derived from Nα,Nim-dibenzyloxycarbonyl tetrapeptide ester by the catalytic hydrogenolysis. These tri- and tetrapeptide components were prepared with stepwise syntheses free from racemization.
  • Teruo Matsuura, Yoshihiko Kitaura
    1968 Volume 41 Issue 10 Pages 2483-2485
    Published: 1968
    Released: March 27, 2006
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    Stereochemistry of the photopinacolization of unsymmetrical aromatic ketones was investigated. In the photopinacolization of aromatic ketones of type PhCOR in isopropyl alcohol, the dl: meso ratio of diastereoisomeric pinacols formed tends to increase as the size of the substituent R becomes bulkier. The dl: meso ratio of pinacols obtained from p-substituted acetophenone, p-X–C6H4–COCH3, is about 1 in the cases that X is H, Cl, and CH3, whereas the ratio is 1.25 in the case of X=OCH3. The photopinacolization of acetophenone in three solvent systems cyclohexane, isopropyl alcohol, and benzene-isopropyl alcohol, was also investigated, and no solvent effect was observed on the dl: meso ratio of acetophenone pinacols.
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