Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 63 , Issue 2
Showing 1-50 articles out of 69 articles from the selected issue
  • Satoshi Kawai, Kiyoshi Arakawa
    1990 Volume 63 Issue 2 Pages 307-314
    Published: 1990
    Released: June 05, 2006
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    A statistical thermodynamic study of liquid organic compounds has been worked out on the basis of a liquid model: a liquid is regarded as an assembly of particles immersed in a uniform background potential resulting from the attractive forces between molecules. In the model the equation of state is expressed as a sum of the term derived from the analytical solution of the Percus–Yevick equation and that from the background potential. Calculations of thermodynamic functions for five liquids (benzene, carbon tetrachloride, toluene, chloroform, cyclohexane) have been performed. The results show the effectiveness and reasonableness of the theory with the evidence of coincidence of calculated values and observed ones.
  • Shinsaku Fujita
    1990 Volume 63 Issue 2 Pages 315-327
    Published: 1990
    Released: June 05, 2006
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    The notation based on the subduction of coset representations (the SCR notation) is presented for the systematic characterization of molecular symmetry. The positions of a parent skeleton are divided into orbits on which the corresponding coset representations (CRs) act. Each of the CRs is then subduced to the subsymmetry that characterizes a molecule derived from the skeleton. The resulting subduced representations are further reduced into CRs, which provide a basis of the SCR notation. The SCR notation is more discriminative than the point-group notation as well as than the framework-group notation. A new concept “unit subduced cycle index” is introduced in order to determine which subsymmetry is realized if we begin with a parent skeleton of a given symmetry.
  • Hiroko Suezawa, Tomoaki Yuzuri, Minoru Hirota, Yoshio Ito, Yoshiki Ham ...
    1990 Volume 63 Issue 2 Pages 328-334
    Published: 1990
    Released: June 05, 2006
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    The 15N, carbonyl 13C, and amide 1H NMR spectra of a series of substituted benzanilides, XC6H4CONHC6H4Y, measured in four solvents of different polarity were correlated with the electronic effects of substituents by the use of the Hammett equation. Except for the 13C chemical shift vs. the σx plot, the ρ-values are positive, showing that the chemical shift tends to move down-field as the substituent becomes electron-withdrawing. Substituent effects could be assumed to arise from a cross conjugation of competing amide and benzoyl resonance structures perturbed via an inductive mechanism by the substituent on the anilino ring. The 15N chemical shifts of XC6H4CONHC6H5 can be expected to be correlated with the rotational barrier, since the down-field shift of the 15N chemical shift (in reference to unsubstituted) benzanilide was ascribed to a steric inhibition of the aryl-carbonyl conjugation. This trend is actually shown by a plot of the 15N chemical shift vs. the rotational barrier of a similarly substituted N,N-dimethylbenzamide. The NH group of 2-methoxy- and 2-chlorobenzanilides was shown to be intramolecularly hydrogen bonded with the ortho substituent (CH3O or Cl) by their 1H NMR and infrared NH spectra.
  • Akio Nakamura, Masakatsu Koshinuma, Kazuo Tajima
    1990 Volume 63 Issue 2 Pages 335-339
    Published: 1990
    Released: June 05, 2006
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    The effects of the chain length of N-alkyl-β-alanine (NAA) (the number of carbon atoms in the alkyl chains; n=0, 2, 4, 6, 8, 10, 12) on the copper(II) complex formation and its properties were investigated. The complex formation constants for two-step reactions were determined by potentiometry using the selective electrodes of copper(II) and hydrogen ions. The values of the complex formation constants decreased with increasing chain length of the alkyl substituents, and became constant for the substituents longer than the butyl group. These results could be explained in terms of a steric hindrance effect of the N-alkyl substituents on these coordination reactions. Each logarithmic function of the solubility and of the solubility product of the 1(Cu):2(NAA)-complexes was found to be expressed, respectively, as a linear function of the number of carbon atoms in the alkyl group. From these data, the standard free energies of the formation and the precipitation of the 1:2-complexes from these constituent ions have been estimated, and a standard free energy diagram was constructed for 1:2-complex formation. It was concluded that the hydrophobic interaction is a driving force which promotes crystalline complex formation from the constituent ions.
  • Yasushi Murakami, Kiyoshi Otsuka, Yuji Wada, Akira Morikawa
    1990 Volume 63 Issue 2 Pages 340-346
    Published: 1990
    Released: June 05, 2006
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    The catalytic activities were examined for the partial oxidation of ethane over various metal oxides. B2O3(30wt%)-added Al2O3 showed the highest catalytic activity in the formation of acetaldehyde (yield: 1.03%) and ethylene (14.6%). Ethylene and acetaldehyde are assumed to be formed via a common reaction intermediate because of the similarity in their kinetic behavior and the similar activation-energy values observed. The second-order dependence of the formation rates for the two products on the pressure of ethane suggests that the two molecules of ethane participate in the formation of the intermediate in the chain reaction mechanism proposed. The active site for the formation of acetaldehyde from the intermediate is suggested to be a highly dispersed boron electron-donated from alumina, but that for ethylene must be different from that of acetaldehyde.
  • Lydia Bonazzola, Jean-Pierre Michaut, Jacques Roncin, Hiroaki Misawa, ...
    1990 Volume 63 Issue 2 Pages 347-352
    Published: 1990
    Released: June 05, 2006
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    γ-Irradiation of phenyl- and diphenylethenes in CFCl3 matrix at 77 K resulted in the formation of the substrate radical cations. 1,1-Diphenyl-2-methylpropene radical cations exhibit a spin density (ρ=0.45) at the β carbon much higher than those of stilbene and 2-styrylnaphthalene radical cations and comparable to those of styrene and α-methylstyrene radical cations. The spin density at the vinyl carbons appears to play an important role in governing the reactivity of the olefin radical cations with molecular oxygen.
  • Masaki Noritake, Ken-ichi Okamoto, Jinsai Hidaka, Hisahiko Einaga
    1990 Volume 63 Issue 2 Pages 353-358
    Published: 1990
    Released: June 05, 2006
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    The formation of an iron(II) complex with 8-hydroxy-7-(8-quinolyl)azo-5-quinolinesulfonic acid (QHQS,H2qhqs) has been investigated on the basis of the electronic absorption spectra, the equilibrium, and the stopped-flow kinetics in a 0.10 mol dm−3 aqueous sodium chloride solution at 25°C with a view to elucidating the coordination selectivity of the ligand. A 1:2 (metal:ligand) complex forms in an acidic medium with a selective coordination of QHQS to iron(II), with its 2-(8-quinolylazo)phenol moiety acting as a terdentate ligand. The complex formation reaction proceeds through a single pathway of Fe2+ with Hqhqs, a ligand species singly protonated at the phenolate oxygen, with the rate constant (k21) of k21=(3.16±0.20)×105 mol−1dm3s−1, to form a mono-ligand complex as the rate-determining step. The coordination of the ligand by 8-quinolyl nitrogen, followed by a rate-determining bonding of phenolato oxygen, was suggested as the reaction mechanism.
  • Itsuo Mori, Yoshikazu Fujita, Keiji Kato, Minako Toyoda, Masao Akagi
    1990 Volume 63 Issue 2 Pages 359-363
    Published: 1990
    Released: June 05, 2006
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    The fluorescence reactions among 4-(4-methyl-2-quinolyl)aminosalicylic acid (MQAS) as a diarylamine compound, hydrogen peroxide as an oxidizing agent, and various metal ions such as cobalt(II) were spectrolluorometrically investigated in the presence or in the absence of various surfactants. The MQAS–hydrogen peroxide solution in the presence of trimethylstearylammonium chloride (STAC) as a cationic surfactant was catalytically converted to a fluorescence product by the coexistence of trace amounts of cobalt(II), and its relative fluorescence intensity at 400 nm in the fluorescence reaction product was proportional to the cobalt(II) concentrations. Moreover, a highly selective and sensitive fluorimetric method for the determination of cobalt(II) using MQAS and hydrogen peroxide in the presence of STAC in basic media was proposed. The calibration graph was linear in the range of 0–45 ng cobalt(II) per 10 cm3 at an emission wavelength of 400 nm, with an excitation wavelength of 320 nm.
  • Tadashi Tokii, Naofumi Watanabe, Michio Nakashima, Yoneichiro Muto, Mi ...
    1990 Volume 63 Issue 2 Pages 364-369
    Published: 1990
    Released: June 05, 2006
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    Bis(μ-carboxylato-O,O′)-diaquabis(1,10-phenanthroline)dicopper(II) dinitrate tetrahydrates, [Cu(RCOO)(phen)(H2O)]2(NO3)2·4H2O, where R=H, CH3, and (CH3)3C, were prepared and characterized by elemental analyses, electronic spectra, magnetic susceptibilities, and X-ray structure analysis. The magnetic susceptibility data conform to the usual dimer equation. The −2J values are 125 cm−1 for formate, 86 cm−1 for acetate, and 99 cm−1 for 2,2-dimethylpropanoate. The crystal structures of [Cu(HCOO)(phen)(H2O)]2(NO3)2·4H2O (1) and [Cu(CH3COO)(phen)(H2O)]2(NO3)2·4H2O (2) were determined by the single-crystal X-ray diffraction method. The crystallographic data are: Compound 1, monoclinic, I2⁄a, a=18.850(2), b=9.775(2), c=17.752(2) Å, β=99.03(1)°, V=3230.4(8) Å3, Z=4, R=0.055 for 2511 observed unique reflections; Compound 2, monoclinic, C2⁄c, a=18.563(4), b=14.272(5), c=14.126(3) Å, β=106.72(2)°, V=3584(2) Å3, Z=4, R=0.082 for 2092 reflections. The complexes consist of dimeric [Cu(RCOO)(phen)(H2O)]22+)] cations with five-coordinated copper ions linked by two carboxylato ions in a syn-syn bridging arrangement. The Cu···Cu distances are 3.103(2) Å for 1 and 3.063(3) Å for 2.
  • Choichiro Shimasaki, Yoshinori Mutou, Eiichi Tsukurimichi, Toshiaki Yo ...
    1990 Volume 63 Issue 2 Pages 370-377
    Published: 1990
    Released: June 05, 2006
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    Thermal decomposition of diphenyl phosphoramidate (1)and phenyl phosphordiamidate (2) was investigated by DTA-TG, IR, 1H NMR, 31P NMR, mass spectroscopy, and TG-GC/MS. The DTA-TG/DTG curve showed that the thermal decomposition of 1 occurred in one stage. Compound 1 melted at about 150°C and decomposed to polyphosphates accompanied with a weight loss of about 60% in the temperature region of 200 to 350°C. It was confirmed from the results of IR, 1H NMR, and TG-GC/MS that this weight loss in TG of 1 is attributed to the liberation of ammonia and phenol and to the production of an insoluble polyphosphate through triphenyl phosphate or a soluble oligophosphate. The fragment ions of diphenyl ether (mz 170) and aniline (mz 93) were recognized in the mass spectrum of 1. This result indicates that phenyl radical and hydrogen atom in both samples transfer between three oxygen atoms and a nitrogen atom around a phosphorus atom. The activation energy of the thermal decomposition was estimated to be 151 kJ mol−1 for 1 and 220 kJ mol−1 for 2. From the DTA-TG/DTG curve of 2, the decomposition in TG showed two stages and proceeded in a similar process to 1. The cleavage of 2 by the electronic impact was also similar to that of 1.
  • Yukinori Minagawa, Fumikazu Yajima
    1990 Volume 63 Issue 2 Pages 378-382
    Published: 1990
    Released: June 05, 2006
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    A fine powder of yttrium(III) oxide has been obtained by calcination of a quasi-stable salt of NH4Y(C2O4)2· H2O, which was prepared by the rapid addition of an aqueous ammonia solution into a strongly acidic yttrium oxalate solution. The particle size distribution weakly depends on the addition time of the aqueous ammonia solution and the agitation speed, and strongly depends on the washing times with pure water and on the calcination temperature of NH4Y(C2O4)2· H2O crystal. The precipitation mechanism of NH4Y(C2O4)2·H2O is discussed in terms of kinetics in the solution.
  • Toshio Takahashi, Jesus Mallen, Dalia Lorenzo, Raj K. Khanna, Masanori ...
    1990 Volume 63 Issue 2 Pages 383-388
    Published: 1990
    Released: June 05, 2006
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    2-Carboxy-15-crown-5 has been prepared by potassium permanganate oxidation in modest yield. Its native conformation has been assessed by using infrared, NMR, and both MM2′ and MNDO calculations. Neutral cation complexes (of the form crown-COOH.MX) of this macrocycle with NaCl, NaBr, NaI, KCl, and CaCl2 have been prepared and studied. It is concluded that the carbonyl oxygen atom is a donor for the ring bound cation, an observation supported by the calculated lowest energy conformation of the non-complexed macrocycle.
  • Yoshihiro Shigemasa, Takaaki Ueda, Hiroyuki Saimoto
    1990 Volume 63 Issue 2 Pages 389-394
    Published: 1990
    Released: June 05, 2006
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    Dihydroxyacetone, DL-glycero-tetrulose, and 2,4-bis(hydroxymethyl)-3-pentulose (2,4-BH-3-P) were favorably formed in a formose reaction by choosing a suitable ratio of water to N,N-dimethylformamide used as solvent or a suitable [thiamine·HCl]/[HCHO] ratio. The formose reaction was strongly affected by the concentration of formaldehyde in the water layer. Under the reaction conditions studied, thiamine decomposed rapidly. 2,4-BH-3-P was isolated from the reaction mixture and characterized by MS, IR, and NMR techniques. A pathway for the formation of 2,4-BH-3-P was also proposed.
  • Katsuhiro Saito, Yoichi Omura, Etsuro Maekawa, Paul G. Gassman
    1990 Volume 63 Issue 2 Pages 395-400
    Published: 1990
    Released: June 05, 2006
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    The reaction of cyclooctatetraene with 1,3-diphenylisobenzofuran afforded two kinds of 1:1 [2π+4π]-cycloadducts, a cage-type 1:1 cycloadduct and two classes of 1:2 cycloadducts. The cage-type compound was formed from one of the [2π+4π]-cycloadducts via an unprecedented second [2π+4π]-cycloaddition reaction in which the double bond of the benzene moiety acted as a dienophile. A similar reaction with dimethyl cyclooctatetraene-1,2-dicarboxylate gave a 1:1 [2π+4π]-cycloadduct and a 1:2 cycloadduct. No cage-type compound was formed.
  • Gong-Xin He, Toshihiko Imato, Nobuhiko Ishibashi, Seiji Shinkai, Tsuto ...
    1990 Volume 63 Issue 2 Pages 401-406
    Published: 1990
    Released: June 05, 2006
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    13C NMR relaxation times (T1s) have been determined for monoazacrown ethers (CA15C5 and CA18C6) and bis(monoazacrown ether)s (BCA15C5, BCA18C6, BOA15C5, and BOA18C6) in the absence and presence of Na+and K+ ions. For the monoazacrown ethers with heptyl side chain and the bis(monoazacrown ether)s with pentamethylene bridge chain marked changes in T1 values are observed upon the complexation, and the changes are dependent on the cation and on the structure of the ligands. The complexation with Na+ ion can give a larger effect on the T1 values for the bis(monoazacrown ether)s of 15- and 18-membered rings, especially on the mobility of the bridging chain carbons, which is indicative of the formation of an intramolecular sandwich complex. On the other hand, the present T1 study again shows the prominent effect of the oxygen in the bridging chain on the complexation of BOA15C5 and BOA18C6. Small differences in T1 values obtained between Na+ complexes and K+ complexes of these two bis(crown ether)s suggest that the complexes take an analogous partial structure for the two cations.
  • Morio Asaoka, Kuniko Nishimura, Hisashi Takei
    1990 Volume 63 Issue 2 Pages 407-411
    Published: 1990
    Released: June 05, 2006
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    Highly diastereoselective routes to cis-fused bicyclo[4.4.0]decane-2,10-diones and bicyclo[4.3.0]nonane-2,9-diones from 5-trimethylsilyl-2-cyclohexen-1-one (1a) and its 3-methyl derivative were established by utilizing an annulation with ω-(alkoxycarbonyl)alkylzinc reagents. Bicyclo[4.4.0]decane-2,8-dione was obtained diastereoselectively by the double Michael reaction of 1a with dienol silyl ether. The diastereoselective Diels–Alder reaction of 1a with cyclopentadiene gave an endo adduct, which can be regarded as a new chiral cyclohexenone synthon, with a high optical purity.
  • Shintaro Nishimura, Nobuyoshi Yasuda, Hiroshi Sasaki, Yoshimi Matsumot ...
    1990 Volume 63 Issue 2 Pages 412-416
    Published: 1990
    Released: June 05, 2006
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    Two new 3-cyano-3-cephem derivatives, potassium 3-cyano-3-cephem-4-carboxylate (2) and potassium 7α-phenylacetamido-3-cyano-3-cephem-4-carboxylate (3), were prepared from 7β-aminocephalosporanic acid. Compounds 2 and 3 showed only weak β-lactamase inhibitory activity in contrast to sodium 7α-[(1R)-1-hydroxyethyl]-3-cyano-3-cephem-4-carboxylate (1), indicating the important role of the 7α-(1-hydroxyethyl) substituent for β-lactamase inhibitory activity.
  • Minae Mure, Kazumi Nii, Shinobu Itoh, Yoshiki Ohshiro
    1990 Volume 63 Issue 2 Pages 417-420
    Published: 1990
    Released: June 05, 2006
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    The reaction of coenzyme PQQ with aminoguanidine, which is known as an inhibitor of quinoprotein amine oxidases, was investigated in vitro. The redox reaction predominantly proceeded at pH 10.0 to give PQQH2 (quinol), whereas deactivation of PQQ occurred at pH 6.7 to give the triazine adduct. In the case of semicarbazide or acetohydrazide as the substrate, azo adduct formation was mainly observed even at pH 10.0. Importance of the C-5 carbinolamine-type intermediate a is discussed.
  • Tadashi Hanaya, Nobuyuki Shigetoh, Hiroshi Yamamoto, Margaret-Ann Armo ...
    1990 Volume 63 Issue 2 Pages 421-427
    Published: 1990
    Released: June 05, 2006
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    1,2,4-Tri-O-acetyl-5-deoxy-5-[(R)- and (S)-ethylphosphinyl]-3-O-methyl-α,β-D-xylopyranoses (8a–d) were prepared from 5-deoxy-5-[(R)- and (S)-(ethoxy)ethylphosphinyl]-1,2-O-isopropylidene-3-O-methyl-α-D-xylofuranoses in two steps. Reduction of 8a–d and their 5-(phenylphosphinyl) congeners with trichlorosilane- triethylamine in benzene smoothly afforded the corresponding title 5-deoxy-5-phosphino-D-xylopyranoses (9a–d and 14a–d) without causing inversion of the ring-phosphorus atom. Treatment of 9a–d and 14a–d with sulfur in benzene efficiently provided the corresponding (phosphinothioyl)-in-ring D-xylopyranoses. Structural and conformational assignments of these newly obtained compounds were made on the basis of mass and NMR (1H and 31P) spectral data.
  • Manabu Kuroboshi, Takashi Ishihara
    1990 Volume 63 Issue 2 Pages 428-437
    Published: 1990
    Released: June 05, 2006
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    Chlorodifluoromethyl ketones CF2ClCOR, where R is an alkyl, aryl, and 1-alkynyl group, underwent the Reformatsky-type aldol reaction with a wide variety of aldehydes or ketones in the presence of acid-washed zinc dust and copper(I) chloride or silver acetate to give the corresponding α,α-difluoro-β-hydroxy ketones in good to excellent yields. Specific activation of zinc metal with the metal salt is essential to achieve high efficiency of the reaction, depending upon the structures of the chlorodifluoromethyl ketones and the carbonyl compounds employed. In-situ formed intermediates in these reactions were successfully detected by 19F NMR spectroscopy, which suggests that their structure is not an α-metallo ketone but an oxygen-metallated species possessing the zinc(II) metal as counter cation.
  • Tetsuro Jintoku, Ken Takaki, Yuzo Fujiwara, Yoshio Fuchita, Katsuma Hi ...
    1990 Volume 63 Issue 2 Pages 438-441
    Published: 1990
    Released: June 05, 2006
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    Direct phenol synthesis from benzene is currently one of the most important problems in modern chemistry. We have reported new phenol synthesis from benzene and O2 via direct activation of a C–H aromatic bond by the Pd(OAc)2/phenanthroline catalyst system. The evidence for direct oxidation of benzene by O2 was obtained using 18O and 2H isotopes. The mechanism was proposed on the basis of these results and the reactions of Ph–Pd σ complex intermediates.
  • Kazuo Kawaguchi, Yasukazu Ohkatsu, Tom Kusano
    1990 Volume 63 Issue 2 Pages 442-446
    Published: 1990
    Released: June 05, 2006
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    Hydrolase model catalysts, N-alkyl-Nα-[2-(D-polyhydroxypentyl)-3-acetyl-4-thiazolidinylcarbonyl]-L-histidinamide (acyclic-type catalyst) and N-(N-alkanoyl-L-nistidyl)-β-D-glucosamine (cyclic-type catalyst), which easily form micelles in water by themselves, have been designed and the stereostructural effects of sugar moieties examined on stereoselective hydrolyses of p-nitrophenyl N-benzyloxycarbonyl-L-(or D-)phenylalaninates. An acyclic-type catalyst is L-selective, while a cyclic-type catalyst is L-selective. The stereorecognition of acyclictype catalysts was found to be performed by a sugar moiety, rather than the histidyl type. Comparisons of the activities of three acyclic-type catalysts having different sugar moieties show that a mannose-derived catalyst is the most stereoselective. Judging from kinetic data, it is concluded that the configuration of OH on C-3 of the sugar moiety takes a significant part in the stereorecognition of a catalyst.
  • Masayuki Hoshi, Yuzuru Masuda, Akira Arase
    1990 Volume 63 Issue 2 Pages 447-452
    Published: 1990
    Released: June 05, 2006
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    Hydroboration of 1-alkylthio-1-alkynes with dicyclohexylborane or bis(1,2-dimethylpropyl)borane proceeded smoothly, adding most of the dialkylboryl group to the α-position of the triple bond. The resulting alkenylboranes afforded either S-alkyl alkanethioates on a controlled oxidation with alkaline hydrogen peroxide in the presence of N,N,N′,N′-etramethylethylenediamine or (Z)-1-alkylthio-1-alkenes on a basic protonolysis, successive treatments with methyllithium, copper(I) iodide and water in the presence of hexamethylphosphoric triamide.
  • Min Shi, Yoshiki Okamoto, Setsuo Takamuku
    1990 Volume 63 Issue 2 Pages 453-460
    Published: 1990
    Released: June 05, 2006
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    Upon UV-irradiation in an alkaline alcohol solution, some triarylmethylphosphonic acids underwent C–P bond cleavage to give triarylmethanes and alkyl dihydrogenphosphates, while, in an acidic or a neutral alcohol solution, they afforded biaryls. Their dimethyl esters gave also biaryls and dimethyl [alkoxy(aryl)methyl]phosphonates, which were derived from the insertion of (dialkoxyphosphinyl)arylcarbenes into the OH bond of the alcohol. The carbene was generated by photo-α,α-elimination of two aryl groups of the phosphonate.
  • Naomichi Furukawa, Eri Hosono, Hisashi Fujihara, Satoshi Ogawa
    1990 Volume 63 Issue 2 Pages 461-465
    Published: 1990
    Released: June 05, 2006
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    A high stereoselectivity in the methylation of 2-pyridylmethyl p-tolyl sulfoxide (2a) with lithium diisopropylamide and iodomethane was observed at low temperature. The chelation of Li+ by both the nitrogen atom in the pyridine ring and the sulfinyl oxygen atom in 2a promotes the stereoselectivity as compared with isomeric sulfoxides.
  • Junji Tanaka, Shuji Kanemasa, Yusuke Ninomiya, Otohiko Tsuge
    1990 Volume 63 Issue 2 Pages 466-475
    Published: 1990
    Released: June 05, 2006
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    Michael addition of methyl 2-(trimethylsilyl)propenoate with organomagnesiums or organolithiums leads to 1:1 and/or 1:2 adduct anions which can be utilized in the subsequent step of Peterson olefination with carbonyl compounds. The 1:1/1:2 ratio depends upon the nature of donor molecules, the reaction conditions such as reaction temperature, polarity of solvent, and rate of addition of the acceptor molecule. Use of acceptors in excess results in the selective formation of 1:2 and/or 1:3 adducts.
  • Junji Tanaka, Shuji Kanemasa, Yusuke Ninomiya, Otohiko Tsuge
    1990 Volume 63 Issue 2 Pages 476-483
    Published: 1990
    Released: June 05, 2006
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    Michael addition of organomagnesiums or -lithiums with methyl 2-(trimethylsilyl)propenoate leads to either 1:1 or 1:2 adduct anions, depending upon the reaction conditions and the reactivity of donor molecules. The adduct anions, both 1:1 and 1:2 types, are quenched with alkyl halides or water in a highly stereoselective manner to produce α-silylated esters. A rigid intramolecular chelation working in the adduct anions is partly responsible for the high selectivity.
  • Mitsuaki Narita, Hitoshi Takegahara, Seiji Ono, Hisaya Sato
    1990 Volume 63 Issue 2 Pages 484-488
    Published: 1990
    Released: June 05, 2006
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    In order to demonstrate the usefulness of “the peptide segment separation method” for syntheses of Asn-rich proteins, the central area of circumsporozoite protein of human malaria parasite plasmodium falciparum, Boc–(Asn–Ala–Asn–Pro)n–OBzl (n=2, 3, 4, 6, 9, 12, and 18), were prepared by the coupling reactions of H–(Asn–Ala–Asn–Pro)k–OBzl (k=1, 2, 3, 6, 9, and 12) with Boc–(Asn–Ala–Asn–Pro)m–OH (m=1, 3, or 6) using DCC and HOBt as coupling reagents. The peptide chains are separated into peptide segments by the tertiary peptide bonds of Asn–Pro moieties and they are assembled by the sequence of Asn–Ala–Asn separated by a Pro residue. Regardless of the increase in the peptide chain lengths of the amino and carboxyl components, the coupling reactions in DMF or NMP were achieved in high yields. The excellent solubility of the peptides in highly polar solvents was preserved in spite of the tendency for an Asn residue to have a high potential for aggregation through hydrogen bond formed by the side-chain amide group. The purification of the peptide series by recrystallization could be completely achieved and HPLC on a gel filtration column showed all the peptides to be monodisperse.
  • Kazuya Otoda, Shunsaku Kimura, Yukio Imanishi
    1990 Volume 63 Issue 2 Pages 489-496
    Published: 1990
    Released: June 05, 2006
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    α-Helical polypeptides having a glyco moiety at one end and a fluorescent probe at the other were prepared and investigated on the interaction with a lipid bilayer membrane. A glycopeptide composed of poly(alanine) and maltose was incorporated into the lipid membrane with the glyco moiety exposed to the aqueous phase and the peptide chain buried in membrane above the phase-transition temperature of the lipid membrane. However, below the phase-transition temperature, the glycopeptide induced the aggregation of dimyristoylphosphatidylcholine (DMPC) small unilamellar vesicles (SUV). Another glycopeptide composed of poly(γ-benzyl glutamate) and glucose also induced the aggregation of DMPC SUV, indicating that such the hydrophobic peptide tends to disturb the membrane structure significantly upon binding. The arrangement of the glycopeptide in a membrane was investigated by using a fluorescent probe connected to the end of the peptide chain. The terminal region of the peptide chain was located at the hydrophobic core of lipid membrane. However, the glycopeptide composed of 25 Ala residues had a smaller fraction taking perpendicular orientation to the membrane than that composed of 15 Ala residues. It was therefore considered that a part of the former glycopeptide molecules exits on the membrane surface, forming aggregates.
  • Hidenori Chikashita, Shin-ichiro Tame, Seiji Yamada, Kazuyoshi Itoh
    1990 Volume 63 Issue 2 Pages 497-501
    Published: 1990
    Released: June 05, 2006
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    The treatment of a variety of 3-methyl-2-phenyl-2-(2-oxoalkyl)benzothiazolines with aldehydes in the presence of 2 equivalents of SnCl4 in dichloromethane at −78°C underwent a carbon–carbon bond cleavage at the 2-position of the benzothiazoline ring releasing an 2-oxoalkyl moiety followed by the concurrent aldol-type reaction with aldehydes to afford the corresponding β-hydroxy ketones. Among the Lewis acids examined, SnCl4 was found to be most effective, while a similar reaction employing trimethylsilyl trifluoromethanesulfonate as an electrophilic promoter mainly gave the corresponding aldol-condensation product. In the case of the reaction with 3-methyl-2-phenyl-2-(1-substituted 2-oxoalkyl)benzothiazolines, a diastereomeric mixture of α-substituted β-hydroxy ketones as cross aldol products was obtained and the anti preference was generally observed for reactions with the benzothiazolines possessing an aromatic ketone moiety in modest to poor selectivity ranging between 69:31 and 57:43. In contrast to this, the reaction of the benzothiazoline possessing an alkyl ketone moiety, 3-methyl-2-phenyl-2-(1-methyl-2-oxobutyl)benzothiazoline, with benzaldehyde showed syn preference in modest selectivity of 70:30.
  • Takashi Hoshino, Yoshio Imamura
    1990 Volume 63 Issue 2 Pages 502-506
    Published: 1990
    Released: June 05, 2006
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    The splitting of methylene peaks in the 1H NMR spectra of surfactants of various alkyl length was studied in aqueous solutions solubilized with aromatic compounds, as a function of the carbon numbers of alkyls. In these spectra the methylene signals of long alkyls split into doublets. The location of the solubilization site is discussed while comparing the results with previous 1H NMR observations of long-alkyl-substituted molecules in aromatic solvents.
  • Hiroshi Matsui, Akira Kunugi
    1990 Volume 63 Issue 2 Pages 507-510
    Published: 1990
    Released: June 05, 2006
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    Three types of the retardation were found for the rate of oxidation of formaldehyde at a platinum electrode in 0.5 mol dm−3 sulfuric acid. These rate retardations are attributed to the blocking of individual reaction sites by strongly chemisorbed species, the inhibition of the pairing of adjacent sites indispensable for the oxidation of formaldehyde, and the accumulation of oxidation intermediates. The oxidation rate under conditions excluding these rate retardations was independent of the potential in the potential range of about 0.4–0.6 V vs. a reversible hydrogen electrode and corresponded to first-order kinetics with respect to the formaldehyde concentrations. These kinetic data are explained in terms of a slow adsorption of formaldehyde molecules.
  • Kazutoshi Kobayashi, Kazuo Araki, Yoshio Imamura, Ryuichi Endo
    1990 Volume 63 Issue 2 Pages 511-515
    Published: 1990
    Released: June 05, 2006
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    The conformation of the copolymer of styrene and spin-labeled methyl methacrylate adsorbed on nonporous silica from solution was investigated by the use of the ESR method. The attached segment fraction of methyl methacrylate, PMMA, in the copolymer was evaluated experimentally. The attached segment fraction of styrene, PST, and the total attached segment fraction, PTOT, in the copolymer were estimated by means of numerical calculations from the value of PMMA. The amounts of saturated adsorption, AS, were obtained as a function of the mole fraction of styrene in the copolymer. The AS values of the copolymers through the mole fractions of styrene of 0.8 increased slightly with the mole fraction of styrene. The AS values of the copolymers at the mole fractions of styrene in excess of 0.8 decreased steeply to that of the styrene homopolymer. The change in the AS values of the copolymers was explicable in terms of the changes in the values of the surface coverage and the values of PTOT. The adsorbed methyl methacrylate homopolymer had a flat conformation, whereas the adsorbed styrene homopolymer had a loopy conformation. When the styrene content in the copolymer increased, the adsorbed conformations of the copolymers varied gradually from the conformation of the methyl methacrylate homopolymer to that of the styrene homopolymer.
  • Tanekazu Kubota, Bunji Uno, Kenji Kano, Toshio Kawakita, Masashi Goto
    1990 Volume 63 Issue 2 Pages 516-519
    Published: 1990
    Released: June 05, 2006
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    In this paper we discuss the oxidation and reduction potentials of a solvated redoxcouple in photoexcited states, these being the extension of our foregoing theoretical treatment pertinent to the energetics of sequential electrooxidation (E1⁄2oxd) and reduction (E1⁄2red) steps. After formulating the ionization potential and electron affinity of solvated molecules by using the E1⁄2oxd and E1⁄2red values, the equations on the oxidation (E1⁄2·excoxd) and reduction (E1⁄2·excred) potentials in excited states are derived. From these the important relation (E1⁄2·excoxd+E1⁄2·excred)=(E1⁄2oxd+E1⁄2red) obtained. For the case of a benzenoid alternant hydrocarbon (BAH) the above left-hand-side summation would become constant. Also, the mutual correlation of the E1⁄2·excoxd or E1⁄2·excred value at 1La excited state to the E1⁄2·excred or E1⁄2·excoxd potential at ground state is discussed for BAH’s. Finally the electron-transfer interaction between an electron donor and an electron acceptor has been considered in photoexcited states by virtue of oxidation and reduction potentials. The equation thus obtained is of the same type as that formulated semiempirically by Rehm and Weller. Our treatment provides theoretical background for the Rehm and Weller equation.
  • Yoshiteru Fujitani, Tetsuo Miyazaki, Kenji Fueki, Nobuyuki M. Masaki, ...
    1990 Volume 63 Issue 2 Pages 520-524
    Published: 1990
    Released: June 05, 2006
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    Recoil T atom reactions were studied in Xe–H2–D2 mixtures at 77 K. The isotope effect on the T-atom reaction with H2 and D2 (k(T+H2→HT+H)/k(T+D2→DT+D)) was measured on the basis of the HT and DT yields. The isotope effect (k(T+H2)/k(T+D2)) is 1.1 in the range of hydrogen concentrations of 0.1–1.0 mol%. Since the small isotope effect (1.1)is similar to the isotope effect (1.0) for a hot T-atom reaction in the gas phase, recoil T atoms are not thermalized at these concentrations in solid xenon and form HT and DT by means of hot-atom reactions. At concentrations of hydrogen of less than 0.1 mol%, the recoil T atoms are thermalized before they encounter the solute hydrogen. The isotope effect increases with a decrease in the hydrogen concentration and amounts to 3.1 at a hydrogen concentration of 0.01 mol%. Since a large isotope effect is expected for the tunneling reaction of T atoms, the large isotope effect (3.1) at 0.01 mol% hydrogen was interpreted in terms of the tunneling reaction of thermalized T atoms. The present results in the solid xenon–hydrogen mixtures were compared with those in the gaseous xenon–hydrogen mixtures reported previously. It was concluded that hot T atoms in the solid xenon at 77 K are deactivated much less effectively than in the gas phase and that they migrate long distances with excess kinetic energies.
  • Hironobu Sakamoto, Kazumasa Yoshikai, Takao Maruyama, Yoshinori Nibu, ...
    1990 Volume 63 Issue 2 Pages 525-532
    Published: 1990
    Released: June 05, 2006
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    Assignment of the normal vibrations of 1,2,3- and 1,3,5-trichloro- and tribromobenzenes was made through the vibrational analyses of the polarized Raman and infrared spectra and also through the normal coordinate calculation. Substitutional effect on the vibrational frequencies and modes of the hydrogen bending and wagging vibrations induced by the halogen atoms is discussed.
  • Toshihiro Tominaga, Shigetoshi Matsumoto
    1990 Volume 63 Issue 2 Pages 533-537
    Published: 1990
    Released: June 05, 2006
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    Interdiffusion coefficients of 1,2-butanediol, 1,4-butanediol, meso-erythritol, xylitol, mannitol, and myo-inositol in water, and of 1-butanol, 1,2-ethanediol, 1,2-butanediol, 1,4-butanediol, 1,2,3-propanetriol, water, and benzene in ethanol have been measured at concentrations close to infinite dilution and temperatures between 278 and 373 K. In water, activation energies are not sensitive to the solutes, decrease with increasing temperature, and are close to that for the self-diffusion of pure water. In ethanol the activation energy is largest for water and smallest for benzene. The quantity Dη⁄T (D, η and T are diffusivity, viscosity, and absolute temperature, respectively) is not sensitive to temperature in water, but shows strong dependence on the temperature for benzene and water in ethanol. Using the corrected Stokes–Einstein equation, the effective radii of the solutes were obtained in ethanol. Some differences in diffusion behavior in ethanol and water are discussed.
  • Hiroyuki Tajima, Masafumi Tamura, Haruo Kuroda, Takehiko Mori, Hiroo I ...
    1990 Volume 63 Issue 2 Pages 538-543
    Published: 1990
    Released: June 05, 2006
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    The reflectance spectra of (BEDT-TTF)5Hg3Br11 and (BEDT-TTF)HgBr3 were measured by using the microspectrophotometric technique in the spectral range from 450 cm−1 to 25000 cm−1. In the former salt, the gap formation due to a metal-insulator transition was observed in the reflectance spectrum at 100 K. In the latter salt, the effective Coulomb interaction and the intra-dimer transfer integral were estimated and compared with the corresponding values of BMDT-TTF and TTF.
  • Joichi Ueda, Midori Takagi
    1990 Volume 63 Issue 2 Pages 544-547
    Published: 1990
    Released: June 05, 2006
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    A method for the coprecipitation of bismuth(III) with hafnium hydroxide followed by a graphite-furnace atomic absorption spectrometric determination is described. Hafnium hydroxide coprecipitates quantitatively 0.05–3 μg of bismuth(III) from 50–400 cm3 of sample solution at pH 5.8–11.2. The presence of 2.5–50 mg of hafnium in 25 cm3 does not affect the atomic absorbance of bismuth(III). The calibration curve is linear for 0.05–3 μg of bismuth(III) in 25 cm3 and passes through the origin. Interference from the presence of large amounts of silver can be eliminated by removing silver as the ammine complex produced by the coprecipitation procedure at above pH 11 with aqueous ammonia. Several other matrix ions investigated do not interfere with the determination in at least a 500-fold mass ratio to bismuth(III). This method was successfully applied to the determination of trace bismuth(III) in commercial metal silver (purity: 99.99%), and is also applicable to the determination of trace amounts of bismuth(III) in water sample.
  • Tetsuaki Nishida, Hiroshi Ide, Yoshimasa Takashima
    1990 Volume 63 Issue 2 Pages 548-553
    Published: 1990
    Released: June 05, 2006
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    The isomer shift in the 57Fe-Mössbauer spectra of xCaO·(90−x)Ga2O3·10Fe2O3 (x=40–60) and xBaO ·(90−x)Ga2O3·10Fe2O3(x=65–70) glasses decreases gradually from 0.28 to 0.16 mm s−1 with increasing CaO or BaO contents. This indicates a formation of nonbridging oxygen atoms in the GaO4 and FeO4 tetrahedra. Large quadrupole splitting (Δ) values ranging from 0.98 to 1.24 mm s−1 indicate a noticeable distortion of the GaO4 and FeO4 tetrahedra. Mössbauer parameters of xCaO·(95−x)Al2O3·10Fe2O3 glasses (x=55–60) are comparable to those of the xCaO·(90−x)Ga2O3·10Fe2O3 glasses, suggesting that the local structures are essentially the same with each other. The glass transition temperatures (Tg) of the calcium gallate, barium gallate, and calcium aluminate glasses are 702–728, 580–583, and 750–773 °C, respectively. It is found that the Tg of several oxide glasses is proportional to the Δ, being expressed by Tg=+b, where “a” is 680 °C mm1 s and “b” is −180°C when the Fe3+ ions are present at substitutional sites of the network former (NWF). The “TgΔ rule” is also applicable to the Fe3+ ions present at interstitial sites, in which case “a” and “b” are 35°C mm−1 s and 260°C, respectively. These findings indicate that the Tg is primarily determined by the distortion of NWF–oxygen polyhedra.
  • Kensei Kobayashi, Tasuku Akagi, Hiroki Haraguchi
    1990 Volume 63 Issue 2 Pages 554-558
    Published: 1990
    Released: June 05, 2006
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    Concentration of trace metals forming complexes with large organic molecules in natural waters have been determined. Natural water samples (sea water and lake water) were filtered through a membrane filter (pore size: 0.45 μm) just after sampling, and concentrated by ultrafiltration. The concentrated natural water samples were fractionated by high performance gel filtration chromatography, and metal ion concentration in each fraction was determined by inductively coupled plasma atomic emission spectrometry and/or by graphite furnace atomic absorption spectrometry. Concentration of zinc forming large molecular complexes (LMC) in sea water was 0.07 ngmL−1, and that in lake water was 0.06 ngmL−1. Copper, iron, vanadium, and molybdenum forming LMC in natural waters were also determined. The present results suggest the existences of LMC-forming metal ions, some of which may be metalloenzymes dissolved in natural waters.
  • Mitsuru Sugita, Masamichi Tsuji, Mitsuo Abe
    1990 Volume 63 Issue 2 Pages 559-564
    Published: 1990
    Released: June 05, 2006
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    Hydrous titanium dioxides in amorphous form (Am-HTDO ) were prepared in a state demineralized as much as possible through different processes. The equiadsorption point (EAP) for anion and cation was determined at an ionic strength of 0.1 with the use of alkali metal chloride solution. The EAP values were strongly affected by the synthetic method, especially hydrolysis pH, and by the kind of probing cations, ranging from 2.7 to 4.5. Chloride ion uptake was not dependent on the kind of coexisting cations. The EAP value of Am-HTDO prepared at pH>13 was appreciably lower than that of Am-HTDO prepared at pH 7–8. The “ion-free” Am-HTDO prepared by using the sol–gel method with Ti[OCH(CH3)3]4 showed approximately the same EAP value as that of Am-HTDO hydrolysed at a similar pH by NaOH solution.
  • Katsura Mochizuki, Asako Iijima, Yumiko Endoh, Yoshihito Ikeda
    1990 Volume 63 Issue 2 Pages 565-570
    Published: 1990
    Released: June 05, 2006
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    Bismacrocyclic Ni(II)Ni(II) and Cu(II)Ni(II) complexes, i.e., 7,7′-polymethylenebis[2,12-dimethyl-3,7,11,17-tetraazabicyclo[1 1.3.1]heptadeca-1(17),2,11,13,15-pentaene]dinickel(II) perchlorates and 7,7′-polymethylenebis[2,12-dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-l(17),2,11,13,15-pentaene]copper(II)nickel(II) perchlorates with polymethylene bridges 2–6-C long, were found to exist in an equilibrium between square planar and octahedral Ni(II) ions in water. The equilibrium constants and the thermodynamic parameters, ΔH and ΔS, for the Cu(II)Ni(II) complexes were evaluated on the basis of the analyses of the temperature-dependent absorption spectra. The formation of octahedral species was found to be exothermic; this reflects the predominant contribution of an exothermic change to the formation of Ni(II)–water bonds. The absolute values of ΔS corresponding to those expected for the liberation of two molecules of water are not in conflict with the equilibrium proposed. For both the Ni(II)Ni(II) and Cu(II)Ni(II) complexes, the equilibrium shifts toward the octahedral side as the polymethylene bridge is shortened.
  • Nagao Kobayashi, Keigo Sudo, Tetsuo Osa
    1990 Volume 63 Issue 2 Pages 571-575
    Published: 1990
    Released: June 05, 2006
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    The iron and cobalt phthalocyanines included in the title have been synthesized. Their absorption spectra are unusual compared to other metallophthalocyanines, showing intense hypochromism in the Q band region. The cobalt and iron derivatives show 4-electron reduction capability in the electroreduction of oxygen over the entire range of pH values and in neutral and alkaline pH, respectively, although the potentials are not necessarily positive enough.
  • Takashi Hayashita, Takahiko Kurosawa, Shinji Ohya, Tatsuo Komatsu, Man ...
    1990 Volume 63 Issue 2 Pages 576-580
    Published: 1990
    Released: June 05, 2006
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    Extractive permeation is demonstrated in the permeation of Zn(II) and Cd(II) chloride complexes through an anion-exchange membrane. A selective permeation between Cd(II) and Zn(II) was observed. This selectivity well corresponded to the sorption selectivity with an anion-exchange resin. Under the large concentration gradient of chloride ions across a membrane, Cd(II) chloride complex was selectively enriched in the receiving solution. The concentration ratios between the source and the receiving solution after 40 h reached 5.8 for Cd(II) and 1.2 for Zn(II) when chloride ions of 0.5 mol dm−3 were added to the source solution.
  • M. S. K. Niazi, M. Zafar Iqbal Khan, J. Ali, M. Ahmad
    1990 Volume 63 Issue 2 Pages 581-585
    Published: 1990
    Released: June 05, 2006
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    Molar conductances of dilute solutions of 2-, 3-, 4-nitrobenzoic and benzoic acids are reported at 25°C in ethanol–water (EtOH–H2O) mixtures over composition range from 0 to 70 wt% of ethanol. The ionization constants and limiting molar conductances of these acids have been computed from the data using Fuoss 1978 conductance equation. Solvent effect on the ionization of acids in EtOH–H2O mixtures has been discussed in terms of free energy of transfer of respective anions of the acids from H2O to EtOH–H2O mixtures. It is found that the order of ionization of these acids in EtOH–H2O system is 2-nitrobenzoic acid>3-nitrobenzoic acid \simeq4-nitrobenzoic acid>benzoic acid.
  • M. M. Abdel-Kader
    1990 Volume 63 Issue 2 Pages 586-589
    Published: 1990
    Released: June 05, 2006
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    The diamagnetic susceptibilities of benzamide, methylbenzamides, and hydroxybenzamides have been accurately measured. From these measurements and the calculated values of the in-plane susceptibilities, the semi-experimental anisotropies have been obtained. The magnetic data are correlated with the arrangement of these molecules in the crystals.
  • D. Klissurski, R. Dimitrova
    1990 Volume 63 Issue 2 Pages 590-591
    Published: 1990
    Released: June 05, 2006
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    A distinct correlation between the reducibility of metal oxides in hydrogen and the strength of the oxygen bond in their surface layer has been found. Simultaneously it has been shown that the widely accepted concept for a correlation between the melting points of oxides and their reducibility needs a critical reconsideration.
  • Takuzo Kurotu
    1990 Volume 63 Issue 2 Pages 592-596
    Published: 1990
    Released: June 05, 2006
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    The polarographic behavior of Cu(II), Pb(II), Tl(I), Sn(II), In(III), Cd(II), and Zn(II) was investigated in the presence of polyethylene glycol (PEG) in 0.1 mol dm−3 potassium chloride. PEG was adsorbed on mercury drops within the potential range from ca.−0.2 through −1.50 V vs. SCE, and shifted the half-wave potentials of Sn(II), In(III), Cd(II), and Zn(II) toward the negative direction, leaving the wave heights unchanged. On the other hand, the polarograms of Cu(II), Pb(II), and Tl(I) were not affected by the presence of PEG. Linear relationships between the wave heights for Cu(II), Pb(II), In(III), Cd(II), Zn(II), and their concentrations were obtained in the presence of PEG. Among these ions, the polarographic waves of In(III) and Cd(II), whose reduction potentials are very close together, became well separated in the presence of PEG. It is, therefore, possible simultaneously determine In(III) and Cd(II) in this medium. Interference between In(II) and Pb(II) was observed in freshly prepared solutions. It is, however, feasible to precisely determine both ions by using PEG as a reduction potential-shift reagent for In(III) in order to eliminate the interference.
  • Takuzo Kurotu
    1990 Volume 63 Issue 2 Pages 597-600
    Published: 1990
    Released: June 05, 2006
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    The simultaneous determination of In(III) and Cd(II) was investigated by d.c. polarography in the presence of polyethylene glycol (PEG) in 0.1 mol dm−3 hydrochloric acid. The PEG shifts the half-wave potential of Cd(II) from −0.67 to −0.82 V vs. SCE and reduces the wave height. A linear relationship between the wave height for Cd(II) and the concentration was obtained in the presence of various molecular weights of PEG. An increase in the molecular weight of PEG also causes a decrease in the wave height. On the other hand, a reduction wave of In(III) was not observed down to the reduction potential for hydrogen at a certain concentration of PEG. It is, therefore, possible to determine In(III) and Cd(II) separately, since Cd(II) can be determined by multiplying by a calibration factor. In(III) can also be determined by the difference between the merged-wave height for In(III) plus Cd(II) and the wave height for the determined Cd(II).
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