Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 53 , Issue 10
Showing 1-50 articles out of 77 articles from the selected issue
  • Jun-ichi Aihara
    1980 Volume 53 Issue 10 Pages 2689-2694
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The ω-technique of Wheland and Mann was introduced into the graph theory of aromaticity in order to improve the resonance energies of nonalternant hydrocarbons. For these compounds, the ω-technique resonance energy was more or less smaller than the resonance energy calculated on the basis of the simplest Hückel MO model. Especially, several compounds thus far considered to be aromatic were predicted to be substantially olefinic with much reduced resonance energies. They are calicene, sesquifulvalene, azulene, dibenzo[cd,gh]pentalene, and cyclohepta[def]fluorene. Many aspects of their chemistry were evidently consonant with the improved resonance energies. Possible limitation of the use of electrophilic substitution as a criterion of aromaticity was discussed. Resonance energies of alternant hydrocarbons are not modified by application of the ω-technique.
  • Kazuo Mukai, Noriko Inagaki
    1980 Volume 53 Issue 10 Pages 2695-2700
    Published: 1980
    Released: April 19, 2006
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    ENDOR observations were carried out for 2,6-di-t-butyl-4-phenylphenoxyl and some of its derivatives. Based on the proton hyperfine splittings, the structure of the aryloxyl monoradicals was investigated in terms of the McLachlan MO calculation. A new stable π-conjugated bis(aryloxyl) biradical, 4,4′-(biphenyl-3,3′-diyl)bis(2,6-di-t-butylphenoxyl), was prepared, and the g- and D-tensor values of the biradical in toluene have been determined from its asymmetric frozen ESR spectrum. The D-tensor values were calculated for the twisted “cis” and “trans” conformers of the biradical molecule, using the McLachlan spin densities of 2,6-di-t-butyl-4-phenylphenoxyl, which is a monoradical half of the biradical.
  • Michiro Hayashi, Hiroshi Kato
    1980 Volume 53 Issue 10 Pages 2701-2710
    Published: 1980
    Released: April 19, 2006
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    18O enriched samples of chloromethyl methyl ether and chloromethyl ethyl ether were prepared and their microwave spectra were measured. The rS structures of fluoromethyl methyl ether, fluoromethyl ethyl ether, chloromethyl methyl ether, chloromethyl ethyl ether, and methyl 2-propynyl ether were re-evaluated from the observed rotational constants obtained under the common constraints and assumptions on the structures of the molecules. A comparison of the rS structures was made between the five molecules and between the molecules and their related molecules.
  • Hiroyoshi Kanai, Kenji Kushi, Kei Sakanoue, Nobuji Kishimoto
    1980 Volume 53 Issue 10 Pages 2711-2715
    Published: 1980
    Released: April 19, 2006
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    Selective cis-isomerization of 1-pentene was carried out by NiX(PPh3)3 (X=halogen and pseudohalogen). First-order plots were obtained except for the iodo-complex. The addition of tin(II) chloride increased both activities and ratios of cis-2-pentene to the trans-isomer. Protic solvents accelerated the isomerization. Isotopic exchange between C2D4 and C2H4 or 1-pentene reveals that a metal hydride addition-elimination mechanism is operative.
  • Yoshiharu Usui, Ei-jurou Kobayashi, Akira Kazami, Shinobu Sakuma
    1980 Volume 53 Issue 10 Pages 2716-2720
    Published: 1980
    Released: April 19, 2006
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    Kinetic studies of the photosensitized formation of hydrogen peroxide and hyperoxide ions in a mixed aqueous solution of eosine, oxygen, and EDTA have been attempted on the basis of a switch-over of the primary processes, i.e., the so-called DD, DR, and DO mechanisms. The rate constants for reactions of E+···E and E+···O2 intermediates with oxygen and EDTA were obtained. The yield of hydrogen peroxide via the DO-initiated mechanism was enhanced as much as one order of magnitude (≈0.012) by the addition of 0.15 mol dm−3 of sodium borate or sodium carbonate. The maximum yield, 0.08, of hydrogen peroxide was obtained in an aerated aqueous solution of 1.0×10−4 mol dm−3 of eosine, 5.0×10−2 mol dm−3 of EDTA, and 8.8×10−2 mol dm−3 of sodium borate.
  • Tsutomu Okuda, Hiroshi Ohta, Hideta Ishihara, Koji Yamada, Hisao Negit ...
    1980 Volume 53 Issue 10 Pages 2721-2723
    Published: 1980
    Released: April 19, 2006
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    We observed the 81Br NQR of several molecular complexes of AlBr3 with amines such as (CH3)3N, C5H5N, C6H5NH2, and (C6H5)2NH. All the 81Br resonance lines were found in the frequency range of 78–86 MHz at room temperature except for AlBr3·2C5H5N. From the Zeeman analysis, it was proved that AlBr3·2C5H5N should be expressed with the molecular formula 2AlBr3·4C5H5N and contains cation species AlBr2(C5H5N)4+ with two 81Br resonance lines near 70 MHz and anion species AlBr4 with four 81Br resonance lines near 80 MHz. The two 81Br resonance lines of AlBr3·(CH3)3N disappeared at about 40 °C due to hindered rotation of the whole molecule. The lower two 81Br resonance lines of AlBr2(C5H5N)4+ have positive temperature coefficients.
  • Akio Takenaka, Minoru Ohki, Yoshio Sasada
    1980 Volume 53 Issue 10 Pages 2724-2730
    Published: 1980
    Released: April 19, 2006
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    Crystals of cytosine: N,N-phthaloyl-DL-glutamic acid complex dihydrate were obtained from an aqueous solution of the two components. The space group is P21/c with unit-cell dimensions of a=5.243(1), b=39.133(6), c=9.192(1) Å, β=93.66(1)°, and Z=4. The structure was solved by the direct method and its parameters were refined by a block-diagonal least-squares method. The complex is formed by the two hydrogen bonds between the oxygen atoms of the ionized α-carboxyl group of glutamic acid and the nitrogen atoms, N(4) and protonated N(3), of cytosine. This binding mode is the same as that found in cytidine: N-benzyloxycarbonyl-L-glutamic acid complex, but quite different from that of 5-bromocytosine: N-acylglutamic acid complexes. The substituted bromine atom at C(5) of cytosine is thought to prescribe the binding mode in complex formation. The binding mode between cytosine and glutamic acid, which might be a possible elementary pattern of protein: nucleic acid interactions, is discussed in terms of dissociation constant.
  • Nobuatsu Watanabe, Satoshi Koyama, Hiroki Imoto
    1980 Volume 53 Issue 10 Pages 2731-2734
    Published: 1980
    Released: April 19, 2006
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    The mechanism of thermal decomposition of graphite fluoride, (CF)n in a vacuum was studied by means of chemical and gas analyses, and the measurement of crystallinity. The crystallinity of (CF)n was slightly improved in the step of initial decomposition. The fluorine/carbon atomic ratio of initial gaseous product evolved by decomposition was about 2. The product is CF2 or C2F4, and then it gives several compounds by secondary reaction. Every second layers of (CF)n are decomposed, and the evolved molecules or radicals abstract fluorine atoms which are bonded to the neighboring two layers.
  • Akira Fujishima, Yasuhisa Maeda, Kenichi Honda
    1980 Volume 53 Issue 10 Pages 2735-2741
    Published: 1980
    Released: April 19, 2006
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    Quantum efficiencies of photoelectrochemical reactions on n-type and p-type semiconductor electrodes can easily be determined by the measurement of temperature changes of the surface of semiconductor electrodes by use of thermistors. The quantum efficiencies are intrinsic, since only the absorbed light quanta contribute to temperature change. The merits of the method, simplicity and applicability to the semiconductor of large surface reflectance, are discussed. The intrinsic quantum efficiencies were compared with those obtained by the usual chemical actinometric method.
  • Seiichi Sumi, Tadashi Watanabe, Akira Fujishima, Kenichi Honda
    1980 Volume 53 Issue 10 Pages 2742-2747
    Published: 1980
    Released: April 19, 2006
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    Flatband potential (Efb), which coincides with the Fermi level in energy, was determined for AgCl and AgBr electrodes by electrochemical measurement of the capacitance of the space charge layer of a semiconductor in contact with a solution. The values of Efb for both AgCl and AgBr electrodes in an electrolyte solution were −4.8 V vs. vacuum. The energy levels of the electrodes could be determined from this value. The behavior of the AgCl electrode is somewhat like an n-type semiconductor, and that of the AgBr electrode very much like an intrinsic semiconductor. The Efb values for the AgCl and AgBr electrodes change cathodically in electrolyte solutions with Cl and Br ions, respectively, but not with H+ or OH ions. This seems to be associated with the Ag+ ion effect in spectral sensitization. It is concluded that the Ag+ ion effect arises from a downward shift of the band edge of silver halides.
  • K\={o}ji Kishimoto, Hiroshi Suga, Syûzô Seki
    1980 Volume 53 Issue 10 Pages 2748-2754
    Published: 1980
    Released: April 19, 2006
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    A computerized adiabatic calorimeter system operating in the temperature range 13–300 K is described. A digital voltmeter is used for energy measurement and the duration of energy input is determined by a program unit operated by 1 Hz pulse. Temperatures of the calorimeter are measured by a 25 Ω platinum resistance thermometer and an automated ac double bridge. The measured resistance is converted into temperature (IPTS-68) by a calibration table stored in a mini-computer. Criterion for the realization of thermal equilibration is that a temperature drift calculated from the latest six data becomes smaller than a preset value, usually 7×10−8 Ω s−1. The system is able to measure the heat capacity of solid and liquid in an intermittent heating mode and gives the computed results during measurement. Some examples of the test runs on cyclohexanol crystal are shown and the results are compared with those obtained by manual measurements by use of dc Müller bridge. A relaxational heat capacity anomaly observed in glassy crystalline state of cyclohexanol is discussed in correlation with a secondary relaxation observed by previous dielectric measurement.
  • Nobuo Nakamura, Hiroshi Suga, Syûzô Seki
    1980 Volume 53 Issue 10 Pages 2755-2761
    Published: 1980
    Released: April 19, 2006
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    Low-temperature calorimetric quantities were determined for cyclohexene oxide and cyclohexanone in the temperature range between 13 and 300 K. Molar heat capacity at saturation pressure of the condensed phases, transition and melting temperatures, and enthalpies of transition and melting were measured by an on-line automated adiabatic calorimeter with intermittent heating mode. Purities of both calorimetric specimens were determined from their melting behavior. The following thermodynamic quantities, CS°, SS°, [HS°(T)−HS°(0)]/T, and −[GS°(T)−HS°(0)]/T were tabulated at selected temperatures. The entropies of melting of both compounds were compared with those of cyclohexanol and cyclohexane. A factor affecting the entropy of melting was discussed from the viewpoint of non-globularity of the constituting molecules. The discussion was extended to the thermal stability of a number of orientationally disordered crystals so far studied.
  • Tomoko Sato-Toshima, Minoru Sakiyama, Syûzô Seki
    1980 Volume 53 Issue 10 Pages 2762-2767
    Published: 1980
    Released: April 19, 2006
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    Enthalpies of combustion of 1,2-, 1,3-, and 1,4-dicyanobenzenes were determined by precision oxygen-bomb calorimetry. Enthalpies of sublimation of these compounds were obtained by the measurement of temperature dependence of vapor pressure. The standard enthalpies of combustion ΔHc°(298.15 K)/kJ mol−1 and the standard enthalpies of sublimation ΔHS(298.15 K)/kJ mol−1 are as follows: −4000.36±0.67 and 86.9±1.5 for 1,2-dicyanobenzene; −3992.29±0.75 and 90.1±1.5 for 1,3-dicyanobenzene; −3988.04±0.59 and 88.8±1.5 for 1,4-dicyanobenzene, respectively. Thermochemical destabilization energies were estimated by comparing the derived standard enthalpies of formation in gaseous state with those estimated for hypothetical non-destabilized molecules. They were discussed in terms of electrostatic interactions between highly electronegative and dipolar cyano substituents on one and the same benzene ring. Dipole moments of the dicyanobenzenes in benzene and dioxane solutions are reported in Appendix.
  • Junzo Sunamoto, Tadashi Nomura, Hiroshi Okamoto
    1980 Volume 53 Issue 10 Pages 2768-2772
    Published: 1980
    Released: April 19, 2006
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    The permeation of a novel pyrene-labeled phosphatidylcholine, DPDL (1,2-bis[10-(1-pyrenyl)decanoyl]-sn-glycero-3-phosphatidylcholine), into the dipalmitoyl and egg phosphatidylcholine liposomes was studied. DPDL can adopt a sandwich conformation at the ground state, which comes in the fluorescence excimer emission. The fluorescent probe undergoes the initial rapid adsorption onto the liposome surfaces along with the instantaneous fluorescence enhancement followed by the relatively slow permeation into and diffusion in the liposomal bilayers. Through monitoring the relative quantum efficiency, IeIm (see text), during the permeation, suggestive information about the bilayer structure is obtained at least around the probe. The initial binding to and the subsequent diffusion in the membrane occur mostly as the monomeric form of the probe. At lower temperature without cholesterol the bilayer structure seems to be a lipid-separated conformation (Fig. 1 (c)) and above the chain-melting transition the bilayer seems to exist as a lipid-intimate conformation (Fig. 1 (b)). These results completely coincide with those obtained in our previous study on the codispersion of the probe with phospholipids (J. Sunamoto, et al., J. Am. Chem. Soc., 102, 1146 (1980)).
  • Junzo Sunamoto, Tomiko Hamada, Hiroki Murase
    1980 Volume 53 Issue 10 Pages 2773-2777
    Published: 1980
    Released: April 19, 2006
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    It was found that several lipophilic agents, such as cis-, trans-ethyl decaprenoate and their structural analogues, significantly induce the liposome-liposome fusion when incubated together a set of two different liposomes, the A-liposome containing a marker and the B-liposome involving a lipophilic agent. The rate and extent of fusion were followed spectrophotometrically by monitoring the leakage of an amphiphilic marker, Bromothymol Blue, from the fused liposomes. Fusion was also visualized directly by electronmicrographic technique. When only A-liposome was incubated or when a blank liposome containing no lipophilic agents was added to the A-liposome after the preincubation, neither the fusion nor the marker release was observed at least in periods of several hours. Also, neither fusion nor the marker release was observed when either A- or Bliposome or both were multicompart-ment liposome. Removing cholesterol from liposome significantly depressed the fusion. The effect of cholesterol was more prominent on the A-liposome side. trans-Ethyl decaprenoate was more effective about three-fold to induce the fusion than the cis-isomer. Interestingly, the effect was parallel to the antihypertensive activity of the agent.
  • Junzo Sunamoto, Masaharu Shironita, Noriaki Kawauchi
    1980 Volume 53 Issue 10 Pages 2778-2781
    Published: 1980
    Released: April 19, 2006
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    The efficiency of encapsulation of several divalent metal ions, mainly Zn(II) ion, into egg lecithin liposomes has been investigated with particular attention to the stability of liposomal membranes against the transition metal(II) ions. The stronger interaction of metal ions to lecithins led to the less formation of liposomes. The addition of a suitable amount of nonionic detergent, 2-[ω-hydroxypentadeca(oxyethylene)-α-yl]-1,3-bis(dodecyloxy)propane (2C1215G, see text), enhanced the encapsulation of Zn(II) and Cu(II) ions in liposomes. The stoichiometric measurement for the binding of Zn(II) ion to single compartment liposomes of egg lecithin suggested that a Zn(II) ion is interacting with three or four lecithin molecules on the average in both halves of liposomal bilayers. Even under the circumstances, the bilayer structure of liposomes was certainly kept stable, which was electron micrographically visualized.
  • Kazuaki Harata
    1980 Volume 53 Issue 10 Pages 2782-2786
    Published: 1980
    Released: April 19, 2006
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    The crystal structure of α-cyclodextrin–m-nitroaniline hexahydrate complex was determined by X-ray analysis. The crystal is monoclinic and the space group is P21 with Z=2. The cell dimensions are: a=8.054(1), b=13.508(1), c=25.331(2) Å, and β=103.90(1)°. The structure was solved by an inspection of a Patterson map and by a trialand-error method. The refinement was done by the block-diagonal least-squares method to the final R-value of 0.11 for 2351 reflections (sinθ⁄λ<0.49). α-Cyclodextrin molecules are stacked along the a axis in the head-to-tail fashion to form a channel-type structure. Most of the primary hydroxyl groups of α-cyclodextrin are in a gauche-gauche conformation and linked by hydrogen bonds directly or through water molecules to the secondary hydroxyl groups of the next α-cyclodextrin molecule along the channel. The guest m-nitroaniline molecules are linearly arranged in the channel. The α-cyclodextrin ring includes the nitrophenyl group, while the amino group protrudes outside from the secondary hydroxyl side of α-cyclodextrin and is hydrogen-bonded to a primary hydroxyl group of the next α-cyclodextrin molecule. Along the channel, m-nitroaniline molecules are linked to each other by a weak N–H···O hydrogen bond between the amino group and the nitro group. Columns formed by the stack of α-cyclodextrin are closely packed in the crystal, and intermolecular spaces are filled with water molecules which form many hydrogen bonds with each other and with α-cyclodextrin.
  • Kan Kanamori, Tsutomu Morikawa, Kiyoyasu Kawai
    1980 Volume 53 Issue 10 Pages 2787-2791
    Published: 1980
    Released: April 19, 2006
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    Solid and aqueous Raman spectra of the nitroammine series of cobalt(III) complexes, [Co(NO2)n(NH3)6−n](3−n)+ (n=1–6), have been measured for the region of 1500–100 cm−1. The assignments of the Raman bands due to the skeletal vibrations of the complexes have been made on an empirical basis and compared with those of the infrared bands in the literature.
  • Kazuo Nakamura
    1980 Volume 53 Issue 10 Pages 2792-2795
    Published: 1980
    Released: April 19, 2006
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    ESR spectra of the ion pairs of the 9-fluorenone anion radical with 18-crown-6 complexed sodium and potassium ions were examined. From the dependence of the carbonyl 13C hyperfine splitting of the fluorenone anion on temperature and solvent, it was conclude that an ethereal solvent molecule can solvate the crown complexed cation on the opposite side of the anion with respect to the plane of the crown ether ring, equilibrium taking place between the solvated and unsolvated ion pairs in ethereal solution. The unsolvated species of both the potassium and the sodium ion pairs and the solvated species of the sodium ion pair are classified as contact ion pairs, the solvated species of the potassium ion pair a crown separated one. The equilibrium constant between the solvated and unsolvated ion pairs changes with temperature and solvent. From this change the enthalpy changes of solvation process were estimated for several solvents.
  • Yoshio Matsunaga, Kazuhiro Takayanagi
    1980 Volume 53 Issue 10 Pages 2796-2799
    Published: 1980
    Released: April 19, 2006
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    The electrical resistivity of the 5,6: 11,12-bis(epidithio)naphthacene-bromine system (TTT–Brn) was examined over the composition range from n=0.3 to 2.0 using polycrystalline compactions. The room-temperature resistivity shows a minimum of about 7 Ω cm near n=0.5, suggesting the formation of a mixed-valence compound, (TTT)(TTT+)Br. The resistivity increases monotonously with n. No anomaly was found at the composition of (TTT+)Br. The formation of another mixed-valence compound, the ideal composition of which may be expressed by the formula (TTT+)(TTT2+)(Br)3, is indicated by an abrupt change of the resistivity from 100 to 4000 Ω cm around n=1.5. This change is accompanied by an increase of the activation energy for semiconduction by a factor of almost two and also by the change of sign in the variation of the Seebeck coefficient with the temperature from positive to negative. A further increase of the resistivity by a factor of ten was observed between n=1.5 and 2.0. The electronic and vibrational spectra support the coexistence of the TTT molecule and the TTT+ ion near n=0.5 and that of the TTT+ and TTP2+ ions near n=1.5.
  • Yoji Miwa, Kazuo Tsutsumi, Hiroshi Takahashi
    1980 Volume 53 Issue 10 Pages 2800-2803
    Published: 1980
    Released: April 19, 2006
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    Differential heats of the adsorption of carbon monoxide on Cu(II)Y zeolites were calorimetrically determined. The heat of adsorption was larger on Cu(II)Y zeolites than on the NaY zeolite, and increased with the degree of Cu(II) ion-exchange. Repeated adsorption-desorption measurements revealed an increase in the heat of adsorption, which is considered to be due mainly to the migration of copper(II) ions from inaccessible sites for carbon monoxide to accessible ones in the process of adsorption-desorption.
  • Keiko Nishikawa, Nobuko Kitagawa
    1980 Volume 53 Issue 10 Pages 2804-2808
    Published: 1980
    Released: April 19, 2006
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    The energy-dispersive X-ray diffractometer has been applied to the structural study of liquid water. The intensity data are in good agreement with those obtained by the use of an angle-dispersive method. Water has a structural correlation up to only 8 Å at 25 °C.
  • Kenji Shimomura, Toshikazu Nagashima, Akira Sanjoh, Makoto Yoshida, Hi ...
    1980 Volume 53 Issue 10 Pages 2809-2814
    Published: 1980
    Released: April 19, 2006
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    The proton spin-lattice relaxation times T1 and T1D along the static and dipolar magnetic fields have been measured at 18 MHz for the water molecule in powdered hemihydrate gypsum CaSO4·(1/2)H2O. The minima of T1 and T1D were observed at 103T=4.3(233 K) and 7.0(143 K) respectively. These are ascribed to the 180° flip motion of water molecules, with an activation energy of 15.1 kJ/mol. At higher temperatures, the translational diffusion of water molecules becomes dominant; this is not observed in gypsum CaSO4·2H2O. The activation energy of this motion is estimated to be 32.2 kJ/mol. In hemihydrate gypsum, though the diffusion is supposed to be anisotropic, the jumping distance of the water molecule is tentatively examined by Torrey’s lattice diffusion theory.
  • Katsuhiko Miyoshi, Chang Eon Oh, Hayami Yoneda
    1980 Volume 53 Issue 10 Pages 2815-2820
    Published: 1980
    Released: April 19, 2006
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    Outer-sphere association constants KA of inherently achiral cobalt(III)–amine complexes, [Co(NH3)6]3+, [Co(NH3)4(en)]3+, and trans-[Co(NH3)2(en)2]3+ with (R,R)-tartrate anion (d-tart2−) were determined by measuring their weak CD spectra induced when they were dissolved in aqueous d-tart2− solutions at 25 °C. It was found that the KA values are not so different among these three complexes, whereas their molar CD intensity ΔεMX gained by the association with d-tart2− increases with increasing number of their chelate rings. This was tentatively interpreted to mean that the distortion of the Co(III)–N bonds brought about by outer-sphere association with chiral d-tart2− is greater when bidentate ligands (en) are coordinated than when unidentate ones (NH3) are, i.e., when the complex has more chelate rings. Also it was found that the KA value thus obtained for [Co(NH3)6]3+ is much smaller than that determined by measuring the magnitude of its charge-transfer band which newly appears upon the addition of d-tart2−. From the above finding and other experimental results, it was suggested that induced CD is well developed in these achiral amine complexes when the two hydroxyl oxygen atoms of d-tart2− simultaneously form hydrogen-bonds with amine protons of the ligands.
  • Ushio Sakaguchi, Kaiji Morito, Hayami Yoneda
    1980 Volume 53 Issue 10 Pages 2821-2828
    Published: 1980
    Released: April 19, 2006
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    The deuteration rates at malonate methylene groups have been measured for several [Co(mal)2(N)2] ions over the pD range of 2 to 9 at 36.4 °C, where mal=malonate ion, (N)2=ethylenediamine, cis-(NH3)2, 1,3-propanediamine, N,N′-dimethylethylenediamine, cis-(pyridine)2, and 1,10-phenanthroline. The malonate deuteration is acid-catalysed at pD less than about 4 and base-catalysed at higher pD in all the compounds. In the aminocontaining compounds (the first four compounds), the reaction proceeds stereoselectively in both high and low pD regions. Though the degree of the stereoselectivity depends upon the compound, the fast-exchanging hydrogen is, for all the amino-containing compounds, the one which is adjacent to the coordinating nitrogen atom. The mechanisms of acid- and base-catalysed deuteration, as well as the origin of the stereoselectivity, are discussed. For the ethylenediamine and cis-(NH3)2 compounds, reversal of the stereoselectivity takes place at around pD=8 and 9, respectively, and the fast-exchanging hydrogen becomes the one farthest apart from the coordinating nitrogen. Concomitant with this reversal, both malonate and amine exchange rates fall together. Thus, the rate of hydrogen-deuterium exchange at the NH3 groups does not show the usual first-order dependence upon the OD concentration. These observations are explained by a mechanism in which equally reactive malonate and amine hydrogens compete for OD catalyst.
  • Masahiro Takeuchi
    1980 Volume 53 Issue 10 Pages 2829-2833
    Published: 1980
    Released: April 19, 2006
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    The electron capture coefficients, K, defined by Wentworth et al. were measured on several samples in various carrier gas flow-rates at the detector temperatures of 200–320 °C. The effect of the flow-rate on the value of K was considered. The results revealed that the flow-rate dependence of K for each sample was closely related to one of the three electron capture reaction processes. In a sample undergoing the non-dissociative electron capture reaction, the values of K were generally not affected by the flow-rate; they decreased slightly with increasing the flow-rate at higher temperatures. In a sample undergoing the dissociative electron capture reaction, the values of K increased significantly with increasing the flow-rate at all temperatures. In a sample undergoing the dissociative electron capture reaction through an anion radical intermediate, the values of K were slightly or not at all affected by the flow-rate at lower temperatures, but increased gradually with increasing the flow-rate at higher temperatures.
  • Takashi Shibahara, Hisao Kuroya, Masayasu Mori
    1980 Volume 53 Issue 10 Pages 2834-2838
    Published: 1980
    Released: April 19, 2006
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    The aquation rate of trans(NO2,O2)-[(NO2)(en)2CoO2Co(en)2(NO2)]2+ has been measured in acidic aqueous solution at [H+]=0.003–0.25 M and I=0.50 M (LiClO4), the final products being trans-[Co(NO2)(OH2)(en)2]2+ and H2O2 in marked contrast to the acid decomposition of [(NH3)5CoO2Co(NH3)5]4+ where the final products are Co(II) and O2. The reaction consists of two stages, each of which has preequilibrium of protonation. The observed rate constants for the first and second stages are consistent with the formula, k1obsd=k1K1[H+]⁄(1+K1[H+]) (i=1, 2), indicating the existence of protonated reactive forms in both stages. The rate constants, activation parameters and equilibrium constants are k1=7.46 s−1 (25 °C), ΔH1\ eweq=66.9±1.3 k J mol−1, ΔS1\ eweq=−2.9±4.2 J K−1mol−1, and K1=3.44 M−1 (25 °C) for the first stage and k2=0.400 s−1 (25 °C), ΔH2\ eweq=85.4±2.1 kJ mol−1, ΔS2\ eweq=33.5±7.1 J K−1 mol−1, and K2=2.98 M−1 (25 °C) for the second stage. The solution of the reaction intermediate [Co(NO2)(O2H)(en)2]+ has been obtained by ion exchange technique and characterized by the UV and visible spectra. The factors which decide the reaction path are discussed.
  • Toshitaka Gamo, Yoshio Horibe
    1980 Volume 53 Issue 10 Pages 2839-2842
    Published: 1980
    Released: April 19, 2006
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    A gas chromatographic system is applied to shipboard measurement of dissolved argon, oxygen, nitrogen, and total inorganic carbon dioxide in sea water. Gases are stripped from acidified sea water with helium carrier gas, separated by passing through silica-gel and molecular sieve 5A columns, and subsequently analyzed with a thermal conductivity detector and an ultrasonic detector. Ca. 15 min is required to analyze a 3 cm3 sea water sample. Intercalibration by other analytical techniques for oxygen and total carbon dioxide confirmed the accuracy of this method. Vertical profiles of the gases in the Pacific Ocean demonstrate the merit of the method.
  • Akimasa Yajima, Ryoko Matsuzaki, Yuzo Saeki
    1980 Volume 53 Issue 10 Pages 2843-2846
    Published: 1980
    Released: April 19, 2006
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    The reactions of VCl2O and VCl3 with chlorine, and the reaction of VCl3O, formed by the chlorination of VCl2O, with chlorine in the presence of carbon were examined. The products formed by the reaction between gaseous VCl4 and hydrogen at various temperatures, and the behavior of VCl3 and VCl2 on heating in a hydrogen stream were examined. The reaction between VCl2O and chlorine occurs above ca. 120 °C and proceeds markedly above ca. 170 °C to form VCl3O. VCl4 can be obtained by passing the gaseous VCl3O together with chlorine through a carbon bed held at ca. 700 °C. The reaction between VCl3 and chlorine occurs above ca. 80 °C and proceeds markedly above ca. 170 °C to form VCl4. The hydrogen reduction process of VCl4 in the vapor phase may be represented as follows: The reaction between VCl4 and hydrogen, 2VCl4(g)+H2(g)→2VCl3(s)+2HCl(g), proceeds above ca. 500 °C to form VCl3. Subsequently, the hydrogen reduction of the VCl3, 2VCl3(s)+H2(g)→2VCl2(s)+2HCl(g), and the disproportionate of the VCl3, 2VCl3(s)→VCl2(s)+VCl4(g), proceed to form VCl2. Above ca. 620 °C, the reaction between the VCl2 and hydrogen, VCl2(s)+H2(g)→V(s)+2HCl(g), proceeds to form vanadium.
  • Naoyasu Oishi, Yuzo Nishida, Kazuhiko Ida, Sigeo Kida
    1980 Volume 53 Issue 10 Pages 2847-2850
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The electron transfer reactions between various copper(II) complexes and two-electron donors, such as ascorbic acid and 3,5-di-t-butylcatechol, were investigated. Mononuclear copper(II) complexes with a distorted tetrahedral and a trigonal bipyramidal structure, and some binuclear complexes were readily reduced to copper(I) complexes by the two-electron donors, but not mononuclear planar copper(II) complexes. The catalytic activities of these copper(II) complexes for the oxidation of 3,5-di-t-butylcatechol by O2 were studied in relation to the above reactions.
  • Taitiro Fujinaga, Tooru Kuwamoto, Satoshi Okazaki, Masashi Hojo
    1980 Volume 53 Issue 10 Pages 2851-2855
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Electrochemical reduction of elemental sulfur (S8) has been carried out in acetonitrile using a platinum electrode. The products were identified by means of spectrophotometry and ESR. Sulfur is reduced voltammetrically in two steps:
    S_8+2e→S_8^2-, S_8^2-+2e→2S_4^2-
    These products turns into more stable species by the succeeding chemical reactions in a bulk solution as follows:
    2&S_8^2\oversetK\ ightleftarrowsS_6^2-+1/4S_8& &(K=1.6×10^-2)
    &S_6^2-\oversetK_d\ ightleftarrows2S_3^\ ewdot& &(K_d=1.2×10^-3)
    The S42− species was enough active to react with S8 into S82−, which was regarded as the cause of a current maximum on the current-time curve in a controlled potential coulometry of S8 at a potential of the second reduction step.
  • Masashi Hojo
    1980 Volume 53 Issue 10 Pages 2856-2860
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    S4(NH)4 has been prepared in a good yield (80% or more) by the electrolytic reduction (4-electrons) of S4N4 in the presence of a proton donor in acetonitrile. In the proton donor, a fairly high acidity (acetic acid or a stronger acid) and a much higher concentration than would be expected from the stoichiometry was needed. With a low acidity (e.g., phenol) or a low concentration of the proton donor, a side reaction occurred with the formation of H2S and NH3. Under these conditions, a blue species was produced in the course of the electrolysis; this species was confirmed to be S3. The re-oxidation of S4(NH)4, the oxidation of S4N4, and the reduction of S4(NH)4 were also examined in this connection.
  • Yoshinobu Shiokawa, Akiko Sat\={o}, Shin Suzuki
    1980 Volume 53 Issue 10 Pages 2861-2864
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    An adsorption method for determining the distribution of the oxidation states of neptunium in sodium hydroxide solutions is proposed. In the range of sodium hydroxide concentrations of 1–2 M (1 M=1 mol dm−3), the Np(V) was almost entirely adsorbed on zirconium(IV) hydroxide, while both Np(VI) and Np(VII) remained in the supernatant. By means of this adsorption method, it was found that Np(V) in tracer quantities, though it was most stable in acidic or neutral solutions, was not the most stable state in sodium hydroxide solutions. Also, the oxidation and reduction of Np in sodium hydroxide solutions were investigated.
  • Hitoshi Ohtaki, Masayuki Zama, Hidemi Koyama, Shin-ichi Ishiguro
    1980 Volume 53 Issue 10 Pages 2865-2867
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The complex formation of silver(I) ion with glycine and β-alanine was studied at 25 °C in an aqueous solution containing 3 mol dm−3 LiClO4 as a constant ionic medium by means of potentiometric titrations. At a relatively low pH region, the AgHL+ complex (L represents glycinate and β-alaninate ions) was formed, in which the silver ion was coordinated with the carboxyl group of the ligands. At a medium pH range, the AgL and AgL2 complexes were formed. From the formation constants of the complexes, it is suggested that the silver ion within the complexes may be coordinated with the amino group of the ligands and the interaction between the metal ion and the carboxyl group within the complexes is so weak that the interaction does not appreciably stabilize the complexes. At the highest pH region, the hydrolyzed species Ag(OH)L was formed.
  • Junichi Shida, Tsutomu Matsuo
    1980 Volume 53 Issue 10 Pages 2868-2870
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A highly sensitive indirect spectrophotometric method for phosphate was developed. The ion-association complex of molybdophosphate with Methylene Blue was precipitated in a nitric-acid medium. The complex was adsorbed on (1+4 v/v) cyclohexane–MIBK. The excess of Methylene Blue was removed by washing the organic phase with water. The complex was solubilized with a Zephiramine acidic aqueous solution. By measuring the absorbance of Methylene Blue in the aqueous solution at 660 nm, the phosphate was determined. The calibration curve was linear in the 0.31–3.1 μg range of phosphate, and the molar absorptivity was 2.5×105 l·mol−1·cm−1. The absorbance of the reagent blank was 0.019±0.001, and the recommended procedure was applied to the repetitive determination of 1.55 μg of phosphorus. The ten determinations produced a coefficient of variation of 1.6%. Arsenic, germanium and silicon, which form heteropolyacids like phosphorus, interfered seriously.
  • Masahiro Mikuriya, Hisashi Okawa, Sigeo Kida
    1980 Volume 53 Issue 10 Pages 2871-2877
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Binuclear copper(II) complexes with 2-[2-(dialkylamino)ethylthio]ethanol, Cu{R2N(CH2)2S(CH2)2O}X (abbreviated as Cu(R-nso)X, where R=CH3, C2H5, n-C3H7, n-C4H9; X=Br, Cl, NO3), were prepared and characterized by elemental analyses, infrared and electronic spectra and magnetic susceptibilities (80–300 K). They exhibit a band at 22–26×103 cm−1 characteristic of alkoxo-bridged structure. The magnetic data of Cu(n-C4H9-nso)Cl indicate that a strong antiferromagnetic interaction is operating between the copper ions. However, temperature dependence of magnetic susceptibilities of the other complexes do not obey the equation based on a binuclear structure. The crystal structure of Cu(CH3-nso)Br was determined by the single-crystal X-ray diffraction method. The crystals are monoclinic, space group P21/c, a=10.133(2), b=7.858(2), c=14.893(3) Å, β=118.8(1)°, and Z=2. The structure was solved by the heavy atom method and refined by the block-diagonal least-squares method to an R factor of 0.042. The structure consists of alkoxo-bridged binuclear units, Cu2(CH3-nso)2Br2. The coordination geometry of the copper ion is distorted square pyramid. Since the distances between the binuclear clusters are too long to give rise to an intercluster magnetic interaction, it is suggested that some structural change takes place at low temperature.
  • Kunio Ohzeki, Toshiaki Sakuma, Tomihito Kambara
    1980 Volume 53 Issue 10 Pages 2878-2880
    Published: 1980
    Released: April 19, 2006
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    A rapid and sensitive method has been developed for the determination of a trace amount of chromium(VI). It is based on the pre-concentration of chromium(VI) as the diphenylcarbazide (DPC) complex on a mixed resin prepared from finely divided anion and cation exchangers and the subsequent measurement of absorbance of the resin phase after collection on a filter paper as a uniform thin layer. The sensitivity of the method is approximately 100 times higher than the ordinary solution method using 1-cm cell. The extraction of chromium(VI) with tributyl phosphate followed by back extraction into water is effective for reducing the influence of interfering ions.
  • Hideaki Kanno, Kazuo Kashiwabara, Junnosuke Fujita
    1980 Volume 53 Issue 10 Pages 2881-2884
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Bis(1,10-phenanthroline)- and bis(2,2′-bipyridine)chromium(III) complexes containing a seven-membered chelate ligand, 2,2′-bipyridine N,N′-dioxide(bpdo) or 3,3′-dimethyl-2,2′-bipyridine N,N′-dioxide(mbdo) were prepared. Each complex gave only one of two possible pairs of enantiomers resolved by SP-Sephadex column chromatography. On the basis of the circular dichroism spectra, molecular models, and recovery of the optically active free mbdo ligand from the resolved mbdo complexes, it was found that all the enantiomeric pairs consist of Δ(δ) and Λ(λ) isomers involving the skew dioxide chelate ligands in the ob configuration.
  • Kazuo Ando, Takashi Tokoroyama, Takashi Kubota
    1980 Volume 53 Issue 10 Pages 2885-2890
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The substituent effect in the base-catalyzed cyclization reaction of 2,3-bis(2-cyanophenyl)propionitriles (1) to 5-amino-11-cyano-11H-indeno[1,2-c]isoquinolines has been studied and the result is discussed in terms of the dichotomic carbanion reactivities of 1. Preparation of 1 and the tautomerism of 5-acetamido-11-cyanoindeno[1,2-c]isoquinolines between 5H and 11H structures are described.
  • Eizo Matsumura, Masahiro Ariga, Yasuo Tohda
    1980 Volume 53 Issue 10 Pages 2891-2894
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The reactions of 1-substituted 3,5-dinitro-4-pyridones [1-substituents: methyl (1a), 2-pyridyl (1b), 6-methyl-2-pyridyl (1c), and 4-pyridyl (1d)] with diethyl sodio-3-oxopentanedioate give 1-substituted 3,5-bis(ethoxycarbonyl)-4-pyridones and sodio-1,3-dinitro-2-propane. On the other hand, the reactions of the 4-pyridones (1b, 1c, and 1d) with ethyl sodioacetoacetate give ethyl 4-hydroxy-3,5-dinitrobenzoate together with aminopyridine homologues, and that of la gives furo [3,2-b] pyridine derivative. On the basis of the concept of soft and hard acids and bases, a stepwise nucleophilic attack of the anion of β-keto esters at the electrophilic center of the 2 and 6-positions or 2 and 3-positions of the 4-pyridones is proposed to interpret the variations of the reaction courses.
  • Tadashi Masamune, Shingo Sato, Atsushi Abiko, Mitsunori Ono, Akio Mura ...
    1980 Volume 53 Issue 10 Pages 2895-2904
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A number of 3,4-epoxy alcohols, involving critical structural factors for oxetane formation by intramolecular cyclization, were prepared and treated with base under aqueous (KOH in 75% aq DMSO) and anhydrous conditions (NaH in THF). The result of the reactions of cis- and trans-4,5-epoxy-2-rnethyl-2-undecanols, coupled with that of 1-(2,3-epoxybutyl)- and 1-(2,3-epoxy-3-methylbutyl)-1-cyclohexanols (1a and 1b), indicated that the regioselective oxetane formations of 3,4-epoxy alcohols with alkoxide anions are much insensitive to steric hindrance at the attacked oxirane rings, compared with the corresponding reactions with carbanions, while that of 1-(2,3-epoxypropyl)-1-cycloalkanols revealed that the relevant reactions depend on bulkiness of attacking alkoxide anions. Moreover, the result of the reactions of 1-(1,2-epoxycycloalkyl)-2-methyl-2-propanols under the aqueous conditions demonstrated that the oxetane formations are affected seriously by steric hindrance at the attacked oxirane rings, although the result was in striking contrast with the corresponding result with carbanions. On the other hand, the reactions of 3,4-epoxy alcohols under the anhydrous conditions proceeded in different manner, depending on the structures of the epoxides; namely, fragmentation took place as major reactions with some epoxides, while intramolecular cyclization occurred predominantly with other epoxides.
  • Yasuchika Yonezawa, Chung-gi Shin, Yuji Ono, Juji Yoshimura
    1980 Volume 53 Issue 10 Pages 2905-2909
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    N-Cbz- or N-Tos-α-dehydroamino acid (DHA) and its ester were prepared by the condensation of 2-oxo carboxylic acid or ester with benzyl carbamate or p-toluenesulfonamide. Subsequently, the N-protected DHA and its N-free ester thus obtained were coupled with several L-α-amino acid esters and N-protected (Boc or Cbz)-L-α-amino acid respectively by the usual peptide synthetic methods to give a number of different types of dehydrodipeptide. The configurations of all the new DHA and dehydrodipeptides obtained were shown to have (Z)-geometry.
  • Kazuhiko Tanaka, Hideki Uneme, Nobuyuki Yamagishi, Rikuhei Tanikaga, A ...
    1980 Volume 53 Issue 10 Pages 2910-2916
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    The lithium enolates of O-ethyl S-(tetrahydro-2-oxo-3-furanyl) dithiocarbonate and thiocarbonate were found to be efficient reagents for the stereoselective synthesis of α-alkylidene-γ-butyrolactones from carbonyl compounds. The dianion of α-mercapto-γ-butyrolactone was successfully generated by treatment of α-mercapto-γ-butyrolactone with 2.2 equivalents of lithium diisopropylamide in the presence of N,N,N′,N′-tetramethylethylenediamine at −78°C in THF. The dianion thus formed has been utilized for the efficient and stereoselective synthesis of α-alkylidene-γ-butyrolactones from carbonyl compounds.
  • Shigeru Kobayashi, Tsunehiko Fukuda, Hidefumi Yukimasa, Isuke Imada, M ...
    1980 Volume 53 Issue 10 Pages 2917-2920
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Incorporation of an amino acid into the 6 position of the muramic acid moiety of muramyl dipeptide has been achieved, providing an effective means for the synthesis of various new derivatives. Six new muramyl dipeptide derivatives with an N-acylated amino acid were synthesized using these intermediates and their immunological activity was examined. All the derivatives exhibited adjuvant activity on the induction of delayed-type hypersensitivity to N-acetyl-3-(4-arsonophenylazo)-L-tyrosine.
  • Shizen Sekiguchi, Reiko Hikage, Kenmi Obana, Kohji Matsui, Yumiko Ando ...
    1980 Volume 53 Issue 10 Pages 2921-2925
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    In the reactions of 2,4-dinitro- and 2,4,5-trinitro-1-(1-piperidyl)naphthalenes with piperidine in dimethyl sulfoxide, the 1,1-disubstituted anionic σ complex was confirmed to exist with visible absorption and NMR spectra. Especially in the latter case the 1,3-disubstituted anionic σ complex was formed, the cause of formation of which was ascribed to the deactivating effect of 1-piperidyl group on C1-position of a napthtalene ring and the steric effect of 1-piperidyl group on the nucleophilic attack of piperidine on C1-position. These factors make the 1,1-disubstituted anionic a complex unstable.
  • Akio Hashimoto, Haruhiko Aoyagi, Nobuo Izumiya
    1980 Volume 53 Issue 10 Pages 2926-2928
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    A heptapeptide, H–Cly–Pro–Phe–Pro–Ile–Ile–Val–OH (1), was synthesized and found to be indistinguishable from the natural peptide (2), isolated from a tryptic hydrolysate of Hammersten casein by means of chromatography, amino acid analyses, and mass spectrometric measurements. Both peptides (1 and 2) have a strong bitter taste.
  • Masayoshi Isobe, Kazuyuki Yano
    1980 Volume 53 Issue 10 Pages 2929-2932
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Solvolytic reactivity of endo-tetracyclo[5.2.0.02,4.03,5]non-8-en-6-yl p-nitrobenzoate(1-OPNB), endo-bicyclo-[4.1.0]hept-2-yl p-nitrobenzoate(2-OPNB), and endo-bicyclo[4.2.0]oct-7-en-2-yl p-nitrobenzoate(4-OPNB) was investigated in 50% aqueous acetone. 1-OPNB was less reactive than 2-OPNB that has no cyclobutene ring and more reactive than 4-OPNB that has no bicyclobutane ring. Product study in solvolysis of 1-OPNB was undertaken leading to the rearranged tricyclic alcohol as a major product. The importance of conformational factor for anchimeric assistance by bicyclobutane ring is discussed.
  • Akira Yabe
    1980 Volume 53 Issue 10 Pages 2933-2937
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    It was found that the unexpected phenazines were formed as minor products by the low-temperature photolysis of 2,2′-diazidobiphenyls in a rigid matrix. The phenazine formation results from the 1,1′-C–C bond fission of the biphenyl nucleus and suggests the aziridine intermediates. The low-temperature photolysis of 2-azido-2′-methylbiphenyl and 2-azido-2′,4′,6′-trimethylbiphenyl leads to the triplet-derived phenanthridine derivatives as major products.
  • Ryoka Matsushima, Tsuneo Kishimoto, Morio Suzuki, Motonobu Morioka, Hi ...
    1980 Volume 53 Issue 10 Pages 2938-2942
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Parent and substituted flavanones undergo photochemical opening of the pyrone ring to give corresponding 2′-hydroxychalcones in benzene, pyridine, acetonitrile etc., the yields varying from 0 to 70% with substituents. The reaction is depressed by the addition of 1,3-pentadiene, nitrosobenzene, or acrylonitrile. On the other hand, flavanone and 4-chromanone undergo photoreduction in 2-propanol to give reductive coupling products and solvent adducts as isomeric mixtures. 7,8-Benzoflavanone does not undergo photoreduction in 2-propanol but the ring opening reaction instead. Mechanisms have been discussed in terms of the relative contribution and π,π* character in the lowest triplet states.
  • Hideki Machida, Hitoshi Tatemitsu, Tetsuo Otsubo, Yoshiteru Sakata, So ...
    1980 Volume 53 Issue 10 Pages 2943-2952
    Published: 1980
    Released: April 19, 2006
    JOURNALS FREE ACCESS
    Three isomeric triple-layered and two isomeric quadruple-layered charge transfer cyclophanes containing benzoquinone and dimethoxybenzene moieties have been synthesized together with two triple-layered and two quadruple-layered paracyclophanequinones. The structures of the isomers were determined by 1H- and 13C-NMR spectra and/or alternative syntheses. By comparing the CT bands of a series of dimethoxycyclophanequinones with those of the corresponding cyclophanequinones, it is concluded that the CT stabilization of multilayered dimethoxyquinones should be attributed mainly to the π-basicity of the durene ring which faces the acceptor quinone ring and partly to the decreasing π-basicity of dimethoxybenzene ring as the layer number increases. No orientational dependence of quinone and dimethoxybenzene moieties on GT transition was observed in the multilayered series.
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