Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 62 , Issue 10
Showing 1-50 articles out of 70 articles from the selected issue
  • Akimi Ayame, Goro Sawada
    1989 Volume 62 Issue 10 Pages 3055-3060
    Published: 1989
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Regarding aluminas chlorinated at 973–1223 K, which have only a Lewis acidic character without hydroxyl groups and basic sites, the IR spectra of the adsorbed 1-butene were measured and the isomerization of 1-butene and cis-2-butene was performed at 273–323 K. The obtained results were compared with those for aluminas dehydrated at the same temperatures. The IR spectra of the adsorbed 1-butene well resembled that of cis-2-butene, including the absence of peaks due to double-bond and π-allyl carbanion species, observed even after outgassing at 473 K. During isomerization at 273 K, the initial isomerization reaction rates and cis/trans ratios were greater than those for dehydrated alumina. The ratio decreased rapidly with increasing reaction temperature. The specific reaction rates and the ratio were independent of the chlorination temperature. In the isomerization of cis-2-butene the most thermodynamically unstable molecule, 1-butene, was formed preferentially. The obtained results could be interpreted by an isomerization mechanism through a doubly bonded intermediate, i.e., the allylic butenyl cation.
  • Shigenobu Hayashi, Kikuko Hayamizu
    1989 Volume 62 Issue 10 Pages 3061-3068
    Published: 1989
    Released: June 27, 2006
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    High-resolution solid-state 31P NMR spectra have been measured for inorganic alkali phosphates with different condensations in the PO4 units, and the isotropic chemical shift and anisotropy have been determined. The isotropic chemical shifts in alkali orthophosphates do not correlate directly with the cation size. The hydration effects have been carefully examined by means of a 1H decoupling experiment and by the heat treatment of the materials, accompanied by thermogravimetric analysis. Hydration causes an upfield shift in Na3PO4, K3PO4, and Na4P2O7, while it causes a downfield shift in Rb3PO4 and Cs3PO4. All the five peaks observed in the K4P2O7 sample can be ascribed to anhydrous species; this is in contrast to the findings of previous works. The field-dependence experiments definitely demonstrate that the splittings in K4P2O7 and (KPO3)n are caused by inequivalent sites.
  • Kohshin Takahashi, Tetsuo Terashima, Teruhisa Komura, Hiroto Imanaga
    1989 Volume 62 Issue 10 Pages 3069-3074
    Published: 1989
    Released: June 27, 2006
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    The fluorescence of parent porphyrins in ZnPC2bpy+(n), (PC2bpy+(n), 5-[n-[2-[4-(4-pyridyl)pyridinio]ethoxyl]phenyl]-10,15,20-triphenylporphyrin bromide, n=2,3, and 4), and ZnPC8bpy+(3), (PC8bpy+(3), 5-[3-[8-[4-(4-pyridyl) pyridinio]octyloxy]phenyl]-10,15,20-triphenylporphyrin bromide), was effectively quenched in non-coordinating solvents, such as o-dichlorobenzene and dichloromethane, because the pyridyl group in bpy+ (ω-[4-(4-pyridyl)pyridinio]alkyl group) was coordinated to zinc in porphyrin. On the other hand, the fluorescence of parent porphyrins in ZnPC2bpy+(3), ZnPC2bpy+(4), and ZnPC8bpy+ (3) was partly quenched in such coordinating solvents as N,N-dimethylformamide and pyridine. However, only the fluorescence of the parent porphyrin in ZnPC2bpy+(2) was effectively quenched, even in coordinating solvents. The hydrophobic interaction between the porphyrin ring and bpy+ in ZnPC2bpy+(2) may be considerably large, for bpy+ in ZnPC2bpy+(2) is covalently linked to the ortho position of the phenyl group in ZnTPP, (TPP 5,10,15,20-tetraphenylporphyrin), by a short chain. The emission was effectively quenched by the photoinduced electron transfer from the porphyrin ring to bpy+, because the axial coordination or the hydrophobic interaction gave bpy+ access to the porphyrin ring.
  • Shoji Yamashita, Arthur G. Szabo, Donald T. Krajcarski, Nobuyuki Yamas ...
    1989 Volume 62 Issue 10 Pages 3075-3080
    Published: 1989
    Released: June 27, 2006
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    Interactions of a basic tripeptide, lysyl-tryptophyl-lysine (LTL) with dimyristoylphosphatidylserine (DMPS) were investigated by fluorescence spectroscopy. An interacting LTL–DMPS complex assumes two distinctly different conformations in the lipid bilayer depending on the thermotropic phase of lipid. At temperatures below the gel–liquid crystalline phase-transition temperature (Tc), LTL binds to the polar head groups of DMPS through electrostatic force, and the tryptophan residue is located on the surface of the membrane because of the rigidity of the head groups. Above Tc, it assumes a conformation such that the tryptophan residue slips deeply into the DMPS bilayer. The temperature dependence of the fluorescence quenching by acrylamide supported the penetration of the tryptophan upon the phase transition of DMPS. A fluorescence decay analysis based on the photophysical deactivation mechanism of tryptophan residue has revealed a peculiar interaction of LTL with DMPS in the bilayer.
  • Masakazu Kita, Kazuaki Yamanari, Yoichi Shimura
    1989 Volume 62 Issue 10 Pages 3081-3088
    Published: 1989
    Released: June 27, 2006
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    A series of mixed complexes [Co(pyt)3−n (diamine)n]n+ (n=0, 1, and 2; pyt=2-pyridinethiolate(1—) and diamine=ethylenediamine, (R)-propylenediamine, or 2,2′-bipyridine) have been prepared and characterized by means of their visible and ultraviolet absorption, circular dichroism, and magnetic circular dichroism spectra. In the [Co(pyt)3] or [Co(pyt)2(diamine)]+ complex, only one geometrical isomer, mer(S) or trans(S) respectively, has been obtained. The [Co(pyt)(en)2](ClO4)2 complex, which was spontaneously resolved, had an orthorhombic space group of P212121, with a=12.406(1), b=12.754(1), c=11.621(4) Å, V=1838.7(6) Å3, and Z=4. The refinement of 2276 reflections (Mo Kα radiation) led to R=0.049. The Co–N bond trans to the pyt sulfur atom was longer by 0.023(11) Å than the cis one. The novel oxidation product [Co(2-pyridinesulfenato-N,S)(en)2]2+ was photochemically converted into the N,O-chelated linkage-isomer [Co(2-pyridinesulfenato-N,O)(en)2]2+ in the solid state, accompanied by ring-expansion from a four- to a five-membered chelate ring.
  • Toshio Nakamura, Hisakazu Higuchi, Kosuke Izutsu
    1989 Volume 62 Issue 10 Pages 3089-3092
    Published: 1989
    Released: June 27, 2006
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    The response of organic polymer membrane electrodes, constructed by coating a platinum disk with polyacrylamide (PAA) coupled to acyclic poly(oxyethylene) derivatives, tetraethylene glycol monododecyl ether (POE4) and hexaethylene glycol monododecyl ether (POE6) was studied in acetonitrile (AN) and N,N-dimethylformamide (DMF). The PAA–POE4 electrode showed Nernstian response to the lithium ion in AN and the magnesium and barium ions in DMF, while the PAA–POE6 electrode showed near Nernstian response to the barium ion in DMF. The PAA–POE4 electrode was applied to study the complexation of the lithium ion in AN with DMF. The formation constants, β1=17 and β2=1.2×102, obtained agreed well with the values obtained previously with an univalent cation sensitive glass electrode. The response of the PAA-POE4 electrode in barium bis(2-ethylhexyl) sulfosuccinate (Ba(DSS)2)–DMF solution has been studied and the results are explained by taking the conductometrically determined association constant (K1A=5.2×102) between Ba2+ and DSS ions.
  • Mutsuo Kodama, Eiichi Kimura
    1989 Volume 62 Issue 10 Pages 3093-3097
    Published: 1989
    Released: June 27, 2006
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    We have investigated the equilibria of complexation reactions of mercury(II) ions with 16-membered macrocyclic dioxopentamine (dioxo[16]aneN5), 18-membered macrocyclic dioxohexamine (dioxo[18]aneN6), and their related compounds by employing a polarographic method and pH-metric titration. Dioxo[16]aneN5, dioxo[18]aneN6, and other dioxo ligands except dioxotetramines were found to form solely 1 : 1 ratio mercury(II) complexes designated as HgH–1L+ with displacement of one amide proton, while the macrocyclic 16-membered monooxopentamine(monooxo[16]aneN5) forms HgL2+ in addition to HgH–1L+. The substitution of amine nitrogen of dioxo[16]aneN5 by the sulfur donor unexpectedly gave no increase in the stability of mercury(II) complex of dioxo ligand, HgH–1L+.
  • Isao Sanemasa, Tatsuyoshi Takuma, Toshio Deguchi
    1989 Volume 62 Issue 10 Pages 3098-3102
    Published: 1989
    Released: June 27, 2006
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    Complex formation using cyclodextrins (CyDs) as hosts and anthracene, phenanthrene, and naphthacene as guests has been studied in aqueous medium at 25 °C by measuring the guest volatilization rate. The results obtained are compared with those previously determined for benzene and naphthalene. Factors governing the host–guest association are discussed based on the dehydration energy of the guest derived from the Henry’s law constant. It was suggested that van der Waals force is the main factor to stabilize the polynuclear aromatic hydrocarbons in the CyD cavity and that the contribution of hydrophobic interaction is less important. The additional van der Waals stabilization does not work fully for naphthacene of the longest molecular axis among the guests studied.
  • Ikunori Azuse, Masahiro Tamura, Keisuke Kinomura, Hideo Okai, Katsushi ...
    1989 Volume 62 Issue 10 Pages 3103-3108
    Published: 1989
    Released: June 27, 2006
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    In order to increase the applications of the water-soluble active ester method, water-soluble acylating reagents, [p-(benzyloxycarbonyloxy)phenyl]dimethylsulfonium methyl sulfate, [p-(t-butoxycarbonyloxy)phenyl]dimethylsulfonium methyl sulfate and [p-(9-fluorenylmethyloxycarbonyloxy)phenyl]dimethylsulfonium methyl sulfate, were synthesized from of p-hydroxyphenyldimethylsulfonium methyl sulfate. These compounds had high solubility (more than 30%) in water and were found to act as excellent water-soluble acylating reagents for the synthesis of N-benzyloxycarbonyl, N-t-butoxycarbonyl, N-9-fluorenylmethyloxycarbonyl amino acid derivatives in aqueous solution. They converted dipeptides to N-acyl-dipeptides in aqueous media as well as amino acids. In addition, they were found to be efficient reagents for protecting the side chains of lysine, ornithine, and cysteine.
  • Yoshinobu Nagawa, Midori Goto, Koichi Honda, Hiroshi Nakanishi
    1989 Volume 62 Issue 10 Pages 3109-3113
    Published: 1989
    Released: June 27, 2006
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    Photolysis of 1,1′-(1,8-naphthylene)-bis(1H-1,2,3-triazole)s (1) in methanol has given new heteroaromatic system compounds, indolo[6,7-g]indoles (2). The spectral properties of these compounds were studied in comparison with those of the corresponding benz[g]indoles (4) obtained from the similar photolysis of 1-(1-naphthyl)-1H-1,2,3-triazoles (3). The 1H NMR and IR spectra of 2 and 4 suggest the existence of a strong intramolecular hydrogen bonding in 2. The X-ray crystallographic analysis of tetraethyl 1H, 10H-indolo[6,7-g]indole-2,3,8,9-tetracarboxy late, 2a, indicates that the molecule has almost twofold rotational symmetry, and the framework is distorted due to the steric overcrowding.
  • Tomoyoshi Mita
    1989 Volume 62 Issue 10 Pages 3114-3121
    Published: 1989
    Released: June 27, 2006
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    The thermotropic behavior of different proteins with phospholipids in monolayers was investigated by measuring the surface pressure and the surface viscosity. When phospholipids, such as dipalmitoylphosphatidylcholine (DPPC) and dimyristoylphosphatidylcholine (DMPC), were mixed with the hydrophobic proteins, such as hemoglobin and β-casein, below their phase transition temperatures (Tc), a considerable expansion of monolayers was observed. On the other hand, when phospholipids were mixed with the hydrophilic proteins, such as bovine serum albumin (BSA) and lysozyme below Tc, no expansion was observed. When DMPC was mixed with different proteins at Tc or above, all mixtures formed slightly deviated monolayers from ideal mixing, independent of a variety of proteins. This type of behavior suggests that the hydrophobic proteins perturb the structure of boundary lipids near the protein molecule below Tc, while the hydrophobic proteins do not perturb the phospholipid structure below Tc because of their low hydrophobicities. At Tc or above the membrane properties are independent of a variety of proteins, because all lipid hydrocarbon chains cause a disordering, even without proteins. In addition, when DPPC was mixed with a hydrophobic protein, such as hemoglobin, the fluidity of monolayer increased significantly.
  • Masahiro Nakada, Chihiro Miura, Hideaki Nishiyama, Futoshi Higashi, To ...
    1989 Volume 62 Issue 10 Pages 3122-3126
    Published: 1989
    Released: June 27, 2006
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    Polychlorobenzenes, polybromobenzenes, and polychloropolybromobenzenes (C6H6−nXn) were photolyzed in benzene solutions; the products were analyzed by the GC/MS method. Both dehalogenation and phenylation were shown to take place competitively, producing (poly)halobenzenes bearing one less halogen atom (C6H7−nXn−1) and (poly)halobiphenyls (C6H6−nXn−1–C6H5) as the major products. Besides these products, terphenyl was produced by a consecutive phenylation of the halobiphenyl formed. Polychlorobenzenes were shown to form the corresponding terphenyls only when a pathway via 2-chlorobiphenyl is possible; however, polybromobenzenes can produce terphenyls through any of the isomeric bromobiphenyls intermediarily formed. Isomerization through m-migration of a chlorine atom was also shown to occur to a considerably lesser extent.
  • Shuntaro Mataka, Hisao Eguchi, Kazufumi Takahashi, Taizo Hatta, Masash ...
    1989 Volume 62 Issue 10 Pages 3127-3131
    Published: 1989
    Released: June 27, 2006
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    Benzotris- (3) and benzobis[1,2,5]thiadiazole (4) were prepared in a moderate yield, respectively, by the reaction of tetrasulfur tetranitride (5) with halocatechols (6) and -resorcinols (7). The reduction of 3 and 4 with Sn powder in a mixture of concentrated hydrochloric acid and dioxane gave benzenehexamine (1) and 1,2,3,4-benzenetetramine (2a) and its 5-methyl derivative (2b) in good yields, as a stable tri- (1·3HCl) and dihydrochloride (2·2HCl), respectively.
  • Masahiro Tsuji, Shinji Yokoyama, Yoji Tachibana
    1989 Volume 62 Issue 10 Pages 3132-3137
    Published: 1989
    Released: June 27, 2006
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    1α, 25-Dihydroxyvitamin D2 (1a) was synthesized by irradiation and subsequent thermal isomerization of (22E)-5,7,22-ergostatriene-1α,3β,25-triol (16a). The triol 16a was obtained via 22-oxo-5α,8α-(4-phenyl-3,5-dioxo-1,2,4-triazolidine-1,2-diyl)-23,24-dinor-6-cholene-1α,3β-diyl diacetate (12) starting from (22E)-5,7,22-ergostatriene-1α,3β-diyl diacetate (10), a precursor of 1α-hydroxyvitamin D2. Introduction of the new side chain with the desired stereochemistry was carried out selectively by the reductive elimination of the β-hydroxy sulfone derived from the C-22 aldehyde (12) and an optically active sulfone, prepared via (S)-2,3-dimethyl-1,3-butanediol from methyl (S)-3-hydroxy-2-methylpropionate. Similarly a C-24 epimer of 1a was synthesized.
  • Kiyoshi Matsumoto, Shiro Hashimoto, Takane Uchida, Tadashi Okamoto, Sh ...
    1989 Volume 62 Issue 10 Pages 3138-3142
    Published: 1989
    Released: June 27, 2006
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    The preparation of hydroxy amides from a wide variety of lactones and amines has been achieved at 9 kbar and 30 or 65 °C. The yields of hydroxy amides were moderate to excellent. Some limitations were encountered in the reaction of 6-hexanolide; for example, diethylamine gave only a 15% yield of the corresponding amide at 8 kbar and 60 °C. 4-Pentanolide did react with extremely unreactive amines such as 4-nitroaniline and diphenylamine, and the product was a mixture of the hydroxy amide and 3-aminobutyric acid.
  • Sadao Arai, Yoshio Hashimoto, Takamichi Yamagishi, Mitsuhiko Hida
    1989 Volume 62 Issue 10 Pages 3143-3149
    Published: 1989
    Released: June 27, 2006
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    The reaction rate of the Ullmann condensation reaction of haloanthraquinone with ethylenediamine (EN) by copper(I) halide catalyst decreased along with the formation of inactive Cu(II) species [Cu(EN)2X2] by one-electron transfer from Cu(I) to haloanthraquinone. However, the combination of Cu(I) and Cu(II) salts, having an OH, OCH3, or OCOR group, enhanced the reaction rate in the following order: CuCl<CuCl–CuCl(OCH3)<CuCl–Cu(OCH3)2<CuCl–Cu(OH)2. In condensation using Cu(OR)2 or CuCl(OCH3) alone, the Cu(II) species was reduced to Cu(I) to form an active catalyst system [Cu(I)+Cu(II)]. On the other hand, CuBr2 or CuCl2 was not reduced and was ineffective for the reaction. These were confirmed by ESR measurements and the presence of a dehalogenation product. Mixed valence species bridged by the alkoxo or hydroxo group was proposed as an active species.
  • Kahee Fujita, Tsutomu Tahara, Toshitaka Koga, Taiji Imoto
    1989 Volume 62 Issue 10 Pages 3150-3154
    Published: 1989
    Released: June 27, 2006
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    Specifically modified linear oligosaccharides were prepared by enzymatic hydrolysis of 6- or 2-O-substituted γ-cyclodextrin by Taka amylase A. These results suggest that the importance of the interactions between hydroxyl groups and the subsites (P–V) of Taka amylase A decreases in the following order; for C-6-OH, S>R>T>Q, U and for C-2-OH, R,S>T>Q, U.
  • Yoshiteru Sakata, Hiroyuki Higuchi, Kazuo Doyama, Takayuki Higashii, M ...
    1989 Volume 62 Issue 10 Pages 3155-3160
    Published: 1989
    Released: June 27, 2006
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    Four types of purinophanes (1, 2, 7, and 10) where a 6-thiopurine ring is bridged between S6- and 9-positions or between S6- and 7-positions were synthesized. Among them (6,9)purinophanes (1, 7, and 10) showed unusual high reactivity toward nucleophiles (MeNH2, Me2NH, OH) at 6-position to give acyclic compounds. The increased rate constants of these compounds against (6,7)purinophanes 2 and 9-methyl-6-(methylthio)purine could not be explained by molecular strain, neighboring group participation, or some electronic effect due to faced π-systems, but successfully explained by the stereoelectronic effect proposed by Deslongchamps. The rate of the reactions in 1, 7, and 10 was increased with an increase in rigidity of the tetrahedral intermediate where lone pairs of two adjacent heteroatoms orient antiperiplanar to the departing group.
  • Jun Nishimura, Motoharu Takeuchi, Hideo Takahashi, Eiji Ueda, Yasuhiro ...
    1989 Volume 62 Issue 10 Pages 3161-3166
    Published: 1989
    Released: June 27, 2006
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    [2+2] Photocycloaddition, cationic cyclocodimerization, and reductive ring enlargement were developed for the syntheses of [2.n]-, [3.n]-, and [4.n]naphthalenophanes, respectively, from α,ω-bis(vinylnaphthyl)alkanes as a single starting material. Using the exclusive syn selectivity of the former two methods, the room required for the intraannular naphthalene-ring rotation in the ring system is determined.
  • Kazuhiro Maruyama, Toshi Nagata, Noboru Ono, Atsuhiro Osuka
    1989 Volume 62 Issue 10 Pages 3167-3170
    Published: 1989
    Released: June 27, 2006
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    A new synthetic method of porphyrins via bis(hydroxymethyl)dipyrromethanes is described. This new method can be utilized for preparation of several unsymmetric porphyrin dimers.
  • Yukie Mori, Yuji Ohashi, Koko Maeda
    1989 Volume 62 Issue 10 Pages 3171-3176
    Published: 1989
    Released: June 27, 2006
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    Crystal structures of 2,2,4,6-tetraphenyldihydro-1,3,5-triazine (1), which shows photocoloration, and its photostable propylamine solvate (2) have been determined. The molecular structure of the dihydrotriazine in 1 and 2 showed that it exists in 2,3-dihydro form in the crystals, but the bond distance of N(3)–C(4) was shorter than a normal C–N single bond, indicating that lone-pair electrons on N(3) interact with the π system of C(4)=N(5)–C(6)=N(1). Comparison of crystal structures of 1, 2, and other inclusion compounds previously determined revealed that the difference in the photochemical behavior of the crystals is attributable to different hydrogen bonding schemes. Photolysis of 1 in the solid state, which was carried out in connection with the structural investigation of the photocolored species, gave 2,4,6-triphenyl-1,3,5-triazine as a main product.
  • Tatsuo Oshikawa, Mitsuji Yamashita
    1989 Volume 62 Issue 10 Pages 3177-3181
    Published: 1989
    Released: June 27, 2006
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    Optically active 1-aminoalkylphosphonic acids were successfully synthesized from chiral carbamate and urea derivatives which were prepared from such chiral substrates as (−)-menthol, (+)-camphor, and (R)-(+)-and (S)-(−)-(1-phenylethyl)ureas by the actions of aldehydes and triaryl phosphites. 1-Aminoalkylphosphonic acid derivatives, thus prepared, have an (R)-(+)- or (S)-(−)-configuration, depending on the chiral source via a retention of the configuration; i.e., (+)-products were prepared from chiral (+)-carbamate and (+)-urea derivatives, and (−)-products from chiral (−)-carbamate and (−)-urea derivatives.
  • Yasuo Futami, Hiroshi Nishino, Kazu Kurosawa
    1989 Volume 62 Issue 10 Pages 3182-3186
    Published: 1989
    Released: June 27, 2006
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    The reactions of 1-arylethene, 1,1-diarylethenes, and 1,1-diarylpropenes with iodine(III) tris(trifluoroacetate) gave 1,2-diaryl-1-alkanones, 1-aryl-2-(4-iodophenyl)-1-alkanones, benzoins, benzils, and iodoethenes. A similar reaction of 1,1,4,4-tetraaryl-1,3-butadiene yielded 1,2,4,4-tetraaryl-3-buten-1-one. The reactions of 1,1,5,5-tetraaryl-1,4-pentadienes and 1,1,6,6-tetraaryl-1,5-hexadienes also gave dicarbonyl compounds. The reaction involves aryl migration. The mechanisms and the utility of the reaction for organic synthesis are discussed.
  • Fumihiro Ojima, Tetsuo Osa
    1989 Volume 62 Issue 10 Pages 3187-3194
    Published: 1989
    Released: June 27, 2006
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    The cyclic condensation of active methylene compounds such as diethyl malonate, dimethyl malonate, ethyl acetoacetate, or acetylacetone and dibromoalkanes such as 1,2-dibromoethane, 1,3-dibromopropane, 1,4-dibromobutane, 1,5-dibromopentane, 1,6-dibromohexane, 1,3-dibromobutane, or 1,4-dibromopentane with electrogenerated superoxide ion was studied electrochemically in N,N-dimethylformamide (DMF) using cyclic voltammetry (CV) and controlled potential macro-electrolysis. The CV shows that electrogenerated superoxide ion reacts with both active methylene compounds and dibromoalkanes in the dissolved oxygen medium. Controlled potential macro-electrolysis of the above components generally yielded cycloalkanes as the main products. In comparison, the chemical method using sodium ethoxide was also carried out. Two reaction mechanisms via the proton abstraction of active methylene compounds with electrogenerated superoxide ion and via the nucleophilic attack of the superoxide ion on dibromoalkanes are presented.
  • Reiji Ohtsuka, Yoshio Morioka, Jun-ichi Kobayashi
    1989 Volume 62 Issue 10 Pages 3195-3201
    Published: 1989
    Released: June 27, 2006
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    The dehydration of t-butyl alcohol (TBA) using various heteropoly compound (HPC) catalysts has been studied. Taking the adsorption of water on the surface of the catalyst into consideration, it is presumed that the dehydration of liquid TBA is governed by a Langmuir–Hinshelwood-like mechanism. Also, the change in the catalytic activity with the amount of HPC supported on the silica suggests that TBA is dehydrated through a pseudo-liquid mechanism in which a few layers of the HPC supported take part in the catalytic reaction. The layer thickness, regarded as a pseudo-liquid phase, depends markedly on the kind of HPC supported. For the dehydration of gaseous TBA, on the contrary, the reaction is found to be of the zero-order; it proceeds through in outer-surface mechanism in which only the outer layer of HPC is effective.
  • Shigeru Sugiyama, Shinji \ {O}higashi, Ryûichi Sawa, Hiromu Haya ...
    1989 Volume 62 Issue 10 Pages 3202-3206
    Published: 1989
    Released: June 27, 2006
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    In the equimolar reaction of acrylonitrile with hydrogen peroxide to 2,3-epoxypropanamide (glycidamide), the selectivity and the yield of the epoxide were improved by adding aq. NaOH solution continuously at a constant rate. The conventional literature procedure, by controlled pH from 7.0 to 7.5, resulted in an unfavorable decomposition of hydrogen peroxide. 2,3-Epoxypropanamide could be easily converted to 2,3-dihydroxypropanamide (glyceramide) by a catalytic amount of commercially available acidic resins.
  • Yasuzo Sakai, Hidefumi Taguchi, Fujio Takahashi
    1989 Volume 62 Issue 10 Pages 3207-3210
    Published: 1989
    Released: June 27, 2006
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    Magnetic anisotropic gel beads (MA gel beads) were prepared by the gelation of a ferrite suspension in a static magnetic field. MA gel beads were found to oscillate in an alternating magnetic field. This oscillation can possibly reduce the thickness of the diffusion layer on the interface between the gel beads and the surrounding solution, so that the substance can be transferred more quickly across the gel–liquid interface. MA gel beads consisted of alginate gel containing ferrite powder and toluidine blue as a pigment. MA gel beads were loaded into a dual glass tube to make a column bed, which was inserted into a coreless coil which produced the alternating magnetic field. The concentration change of the pigment in the effluent from the column was measured during a lapse in time with repeating off and on the input of the alternating magnetic field. The pigment concentration in the effluent upon exposure to the alternating magnetic field increased to twice the maximum value obtained without a magnetic field. The stronger was the static magnetic field at the time of gelation and the alternating magnetic field, the larger was the increase in pigment concentration in the effluent. Also, the higher was the concentration of ferrite in gel beads, the larger was the increase in pigment concentration in the effluent.
  • Kenji Okuyama, Chiyo Mizuguchi, Guiqing Xu, Masatsugu Shimomura
    1989 Volume 62 Issue 10 Pages 3211-3215
    Published: 1989
    Released: June 27, 2006
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    Totally synthetic azobenzene-containing amphiphiles C10AzoC5N+Br and C8AzoC5N+Br (C31H50N3O3Br and C29H46N3O3Br respectively) were crystallized from their solutions by the solvent-evaporation method. Both crystals are triclinic, with the space group of P\bar1 and Z=2. The unit cell dimensions of the former crystal are a=3.233(5), b=0.854(2), c=0.608(1) nm, α=106.96(8), β=86.6(1), and γ=88.3(1)°. Those of the latter crystal are a=3.0098(6), b=0.8553(2), c=0.6084(1) nm, α=72.99(1), β=92.57(2), and γ=95.64(2)°. The crystal structure of C10AzoC5N+B was solved by the direct method and refined by the block-diagonal least-squares method: R=0.082 for 2927 observed reflections (2θ<120°, Cu Kα, λ=0.15418 nm). On the other hand, that of C8AzoC5N+Br was refined by the full-matrix least-squares method: R=0.058 for 2993 reflections (2θ<120°, Cu Kα). The molecular and crystal structures of these compounds are quite similar to those of the homologous compounds, C12AzoC5N+Br and C6AzoC5N+Br. That is, the CnAzoC5N+Br molecules incline about 30° to the bilayer surface to pack in a tail-to-tail fashion. The azobenzene chromophore has a pronounced planarity which makes possible the parallel stacking of adjacent phenyl groups.
  • Kayako Hori, Yuji Ohashi
    1989 Volume 62 Issue 10 Pages 3216-3220
    Published: 1989
    Released: June 27, 2006
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    Two crystal forms 1 and 2 were found for the title compound. DSC measurements showed that the two crystals transform to different mesophases (Sm* I and Sm* J). Crystal data. 4′-Heptyloxy-4-biphenylyl p-[(S)-2-methylbutyl]benzoate, 1, Mr=458.61, C31H38O3, monoclinic, P21, T=298 K, a=15.065(3), b=45.59(2), c=5.636(1) Å, β=95.51(2)°, V=4109(2) Å3, Z=6, dx=1.118 Mg m−3, μ=0.475 mm−1, F(000)=1488; 2, triclinic, P1, a=13.37(2), b=22.96(2), c=10.213(5) Å, α=105.55(5), β=105.22(6), γ=102.31(9)°, V=2775(5) Å3, Z=4, dx=1.102 M gm−3. The crystal structure of 1 has been determined by single crystal X-ray analysis. Final R was 0.109. The crystal has a distinct layer structure similar to that of a smectic liquid crystal. Two of the three crystallographically independent molecules with extended paraffin chains have parallel arrangement, to which the third molecule with a twisted and highly disordered chain is antiparallel. The paraffin chains of the parallel molecules in a layer have close contacts with each other. Such contacts would enhance the intra-layer interaction which causes the transition to Sm* I.
  • Hiroaki Sakurai, Kazuo Urabe, Yusuke Izumi
    1989 Volume 62 Issue 10 Pages 3221-3228
    Published: 1989
    Released: June 27, 2006
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    By the use of fluor-tetrasilicic mica (TSM) as a starting material, La3+-modified pillared TSM was prepared by calcining La3+-exchanged TSM followed by Al-pillaring. Nonmodified pillared TSM managed only a 0.1% conversion for toluene alkylation with methanol, but the alkylation activity was greatly enhanced by the modification to give more than a 7% conversion, the activity level of which was roughly comparable to that of the conventional pillared montmorillonite. The effect of modification greatly depended on the calcination temperature at the pretreatment of La3+-exchanged TSM prior to a pillaring operation; the optimum calcination temperature was between 300 and 400 °C. Other multivalent cations with large ionic radii, such as Ce3+, Ca2+, and Sr2+, were also useful as modifiers. On the basis of the results of measurements involving X-ray diffraction, cation-exchange capacity and IR spectra of the adsorbed pyridine, it was concluded that a part of the thermally dehydrated La3+ ions lost their exchangeability to be fixed on the cation exchange sites of layers, remained between layers even after Al-pillaring, and took charge of the genesis of acidic sites.
  • Hiroshi Sekiya, Yusuke Nagashima, Yukio Nishimura
    1989 Volume 62 Issue 10 Pages 3229-3231
    Published: 1989
    Released: June 27, 2006
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    The laser fluorescence excitation spectrum and the single vibronic level fluorescence spectra from the \ ildeA1B2 state of tropolone have been measured in a supersonic free jet. Some vibronic bands observed in the region of 270–450 cm−1 from the 000 band have been assigned. A tunneling doublet separation for the ν′14 in-plane ring deformation mode has been measured to be 30 cm−1, which is significantly larger than 19 cm−1 for that for the zero-point level, suggesting that the average geometry of the ν′14 mode deviates significantly from that of the zero-point level.
  • Yoshihito Osada, Kayo Umezawa, Aizo Yamauchi
    1989 Volume 62 Issue 10 Pages 3232-3238
    Published: 1989
    Released: June 27, 2006
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    The responses of the current oscillation of the water-swollen polymer gels generated by dc current to the sinusoidal stimulation were investigated. The current oscillation was semiquantitatively analyzed by fast Fourier transform and the phase diagram was made up from power spectra. It was found that the entrainment of oscillation occurred in the polymer gels when the frequency of sinusoidal stimulation was closed to that of parent current oscillation. It was also found that the stronger sinusoidal voltage caused the entrainment in wider frequency range.
  • T. Ken Miyamoto, Kojiro Okude, Kazuyuki Maeda, Hikaru Ichida, Yukiyosh ...
    1989 Volume 62 Issue 10 Pages 3239-3246
    Published: 1989
    Released: June 27, 2006
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    The four optical isomers of mandelato(trans-1,2,-diaminocyclohexane)platinum(II) have been prepared. The CD and NMR spectra of these compounds in solution indicate that the mandelate coordinates to platinum(II) to form a five-membered chelate ring. The X-ray crystal structure analyses of a pair of diastereomers, (R)-mandelato[(1R,2R)-1,2-diaminocyclohexane]platinum(II) and (S)-mandelato[(1R,2R)-1,2-diaminocyclohexane]platinum(II), have confirmed that the skeletal configuration of (R)- or (S)-mandelic acid is retained during the chelation of platinum(II). As a whole, the structural features of both diastereoisomers are analogous to each other. However, slight differences in hydrogen bonding are noticeable in relation to the solubilities. A preliminary animal test against mice leukemia L1210 was carried out using these compounds. The four isomers show different activities. All these facts together support the conclusion that the chiralities of both ammine (carrier) and mandelate (leaving group) influence the antitumor activities of the platinum agents.
  • Makoto Nagase, Yasuhiko Yukawa, Yoshie Inomata, Toshio Takeuchi
    1989 Volume 62 Issue 10 Pages 3247-3251
    Published: 1989
    Released: June 27, 2006
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    Several complexes with the formula of ML2·2H2O (HL=racemic 2-thiazolidinecarboxylic acid, (Remark: Graphics omitted.)–COOH, M=Co, Ni, Zn), anhydrous CdL2 and CdCl2(HL) were synthesized and characterized by means of their infrared absorption and reflection spectra, magnetic susceptibility, thermal analyses, and powder X-ray patterns. In addition, the crystal structure of ZnL2·2H2O was also determined. Crystals of this complex are monoclinic, with the space group P21n with a=7.224(1), b=18.246(4), c=5.306(1) Å, and β=104.57(1)° and Z=2. The structure was solved by the heavy atom technique and refined by a block-diagonal least-squares method to a final R value of 0.056 for 1774 unique reflections. The zinc environment consists of two carboxylic oxygen atoms and two thiazolidine nitrogen atoms from two centrosymmetrically related organic ligands in a square-planar arrangement. Two water molecules in the axial positions complete a tetragonal bipyramidal coordination around the metal atom. No sulfur atom is coordinated to the zinc atom. The infrared absorption spectra and the structure of this zinc(II) complex are discussed in comparison with those of zinc(II) complexes with (S)-4-thiazolidinecarboxylic acid and racemic 4-thiazolidinecarboxylic acid.
  • Kyohko Kobayashi, Yuichi Satsu, Yoshimasa Hoshino, Shinji Arai, Kiyosh ...
    1989 Volume 62 Issue 10 Pages 3252-3259
    Published: 1989
    Released: June 27, 2006
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    Nine complexes of type [RuII(R–CO–CH–CO–R′)3] were examined; only those with R=–CF3 underwent the facial–meridional isomerization in N,N-dimethylformamide (DMF) at the reflux temperature. Qualitative examination of the occurrence of isomerization of the complex with R=–CF3 and R′=–CH3 in various solvents supports the presence of solvent-assisted bond-rupture mechanisms. This complex did not isomerize photochemically in acetonitrile. The isomerization of four complexes with R=–CF3 and R′=–CH3, –C2H5, –CH-(CH3)2, and –C(CH3)3 in DMF at 70–100 °C followed the reversible first-order kinetics. The equilibrium constants, which were temperature independent, decreased from 4.27 to 1.74 in the order cited above. The enthalpies of activation, ranging from 66.4 kJ mol−1 (R′=–CH(CH3)2) to 96.0 kJ mol−1 (R′=–CH3), depended linearly on the atomic bond populations of the Ru–O bonds calculated by means of a modified extended Hückel method.
  • Yoshikazu Fujita, Itsuo Mori, Minako Toyoda, Yoshihiro Nakahashi, Keij ...
    1989 Volume 62 Issue 10 Pages 3260-3265
    Published: 1989
    Released: June 27, 2006
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    A sensitive and selective spectrophotometric determination of palladium(II) based on ternary-complex formation with Phloxine and thiamine was established. The apparent molar absorptivity of the proposed method, which does not require an extraction procedure, was 1.02×105 dm3 mol−1 cm−1 at 565 nm. Only gold(III) in an equimolar ratio of palladium(II) among the metal ion examined interfered. The method was applied to a determination of palladium in palladium carbon and palladium asbestos; the results were in good agreement with those obtained by potassium iodide method, the Michler’s thioketone method and ICP-AES. The sensitivity could be further enhanced by about 20 times over that of spectrophotometry and/or fluorimetry by combining it with a membrane filter preconcentration technique. It was suggested that the collection of an aggregate on a membrane filter depends on the molecular size through observing by an scanning electron microscope.
  • Masatsugu Kajitani, Ryuji Ochiai, Kakushi Dohki, Norikazu Kobayashi, T ...
    1989 Volume 62 Issue 10 Pages 3266-3271
    Published: 1989
    Released: June 27, 2006
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    A one-pot-reaction of (η-cyclopentadienyl)(1,5-cyclooctadiene or dicarbonyl)cobalt(I) with alkyne (diphenylacetylene and phenylacetylene) and a mixture of S8 and Se8 gives (η-cyclopentadienyl)(2-selenolatoethylenethiolato-S,Se)cobalt(III) complex in addition to the corresponding dithiolato and diselenolato complexes. When phenylacetylene was used as an alkyne, a (2-phenyl-2-selenolatoethylenethiolato-S,Se)cobalt(III) complex was formed preferentially rather than the (1-phenyl-2-selenolatothiolato-S,Se)cobalt(III) complex. The separation of the diselenolato and selenolatothiolato complexes from the dithiolato complex was successfully done by utilizing the difference in how these complexes form adducts with tributylphosphine. The dithiolato complexes have more negative reversible half-wave potentials (for reduction) than the diselenolato complexes; the selenolatothiolato complexes have intermediate half-wave potentials.
  • P. P. Mahapatra, L. M. Mahapatra, Bagmi Mishra
    1989 Volume 62 Issue 10 Pages 3272-3277
    Published: 1989
    Released: June 27, 2006
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    Samples of arsenic hydroxyapatite and its solid solutions with calcium hydroxyapatite are synthesized in aqueous media. The samples are characterized by X-ray, infrared spectra, the assignments of phosphate, arsenate, and hydroxyl bands are recorded. The possibility of anion migration in the apatite lattice is proposed. Presence of water, adsorbed in nature, is indicated in the TGA and DTA analysis of the samples. The solubility product, Ksp, of the samples of arsenic hydroxyapatite Ca10(AsO4)6(OH)2, and the solid solutions, Ca10(PO4)6−x(AsO4)x(OH)2, (x=1 to 5) are determined considering the formation of ion pairs [CaHAsO4]0, [CaHPO4]0, [Ca(H2AsO4)]+, and [Ca(H2PO4)]+ in solution. The instability of the samples in solution is indicated from the experimental ΔG0soln. values.
  • Nitya Ranjan Das, Putul Chattopadhyay
    1989 Volume 62 Issue 10 Pages 3278-3282
    Published: 1989
    Released: June 27, 2006
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    A quaternary ammonium salt reagent, Aliquat 336 has effectively been used for radioanalytical separations of molybdenum and tungsten through the techniques of solvent extraction and reversed phase extraction chromatography (RPEC). Studies on solvent extraction revealed that quantitative separations of the elements in a mixture can be achieved by extracting tungsten with ca. 10−4 mol dm−3 solution of Aliquat 336 in cyclohexane from an aqueous solution of 1 mol dm−3 H3PO4. The efficiency of separation of the elements which form varieties of metal salts of poly- and heteropolyanion species in aqueous solution is very much dependent on the types of acids as well as on the reagent concentration. In RPEC system, both the elements were found to be quantitatively extracted by an Aliquat 336 impregnated column of Kieselguhr from an alkaline solution containing a hydroxy compound like tartaric acid. The extracted species were subsequently separated by eluting molybdenum and tungsten respectively with HCl solutions of 0.05 mol dm−3 and 0.1 mol dm−3 concentrations. The purity of the separated species at various stages of their separations was verified by means of gamma-ray spectrometry.
  • Ranjit S. Sarpal, Sneh K. Dogra
    1989 Volume 62 Issue 10 Pages 3283-3290
    Published: 1989
    Released: June 27, 2006
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    The longest wavelength transition in the absorption spectra of β-hydroxy-substituted 1-naphthylamines is long axis polarised, whereas the fluorescence occurs from the more polar, short axis polarized state. This is based on the spectral characteristics in different solvents. Five different prototropic species are formed in the ground state and six species are obtained in the S1 state. The ground state precursor for the formation of zwitterion is the monocation. pKa values for the different prototropic reactions have been calculated in the ground and excited singlet states.
  • Kamaluddin, Nath Mala, W. Deopujari Sushama
    1989 Volume 62 Issue 10 Pages 3291-3297
    Published: 1989
    Released: June 27, 2006
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    The transition state, where primary ligands like CN partially replaced by biomolecules, has been assumed to be interesting from point of view of chemical evolution of oxidoreductase enzymes. Complexes of type [Fe(III)(CN)5(L)]n (where n=2, 3 and L=glycine, imidazole, triglycine, and histidine) are proposed as models for peroxidases and catalases. Detailed kinetic investigations of decomposition of hydrogen peroxide catalyzed by [Fe(III)(CN)5(L)]n complexes at 40 °C over a wide pH range 6.0–11.0 are discussed. The decomposition reaction is highly pH dependent. In alkaline media, initially L is substituted by OH in [Fe(III)(CN)5(L)]; subsequently HOO binds to OH through weak intramolecular hydrogen bonding, formation of peroxo complexes has been proposed to be an active intermediate responsible for accelerating the reaction. Decomposition of hydrogen peroxide catalyzed by [Fe(III)(CN)5(L)]n complexes conforms to Michaelis Menten type of kinetics.
  • Nurul Islam, Girija Maheshwari
    1989 Volume 62 Issue 10 Pages 3298-3302
    Published: 1989
    Released: June 27, 2006
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    The Flory theory has successfully been employed to predict the excess volume, viscosity of mixtures, surface tension, and the ultrasonic velocities of mixtures of molten tetrahydrates of calcium and cadmium nitrates. The agreement in the computed and the experimental values has been good. The excess volume as well as the excess adiabatic compressibility suggest maximum solute–solvent interactions at ca. 0.55 mole fraction of Cd2+.
  • B. Thimme Gowda, P. Jagan Mohana Rao
    1989 Volume 62 Issue 10 Pages 3303-3310
    Published: 1989
    Released: June 27, 2006
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    Kinetics of oxidations of several amino acids (alanine, leucine, aspargine, glutamine, and proline) by N,N-dichloro-p-toluenesulfonamide (generally known as dichloramine-T) have been studied in 1:1 (v/v) water–methanol medium in the presence of perchloric acid. The oxidations of alanine and leucine showed second order kinetics in [oxidant], first order in [amino acid] and inverse fractional order in [H+] over the entire range of [HClO4](0.0005–0.10 mol dm−3) used. But the kinetics of oxidations of aspargine, glutamine, and proline were [H+] dependent. The rate dependence in [oxidant] was second and first orders in [H+] ranges 0.0005–0.005 mol dm−3 and 0.005–0.10 mol dm−3, respectively. The kinetics in [amino acid] for these oxidations were also different. Variation in ionic strength of the medium or addition of the reduced product of the oxidant had no or negligible effects on the rates of reactions. Decrease in dielectric constant of the medium by increasing the methanol composition of the solvent decreased the rate in all the cases. Activation parameters have been computed from the Arrhenius plots. Plausible mechanisms consistent with the observed kinetics have been discussed.
  • Anil Kumar
    1989 Volume 62 Issue 10 Pages 3311-3314
    Published: 1989
    Released: June 27, 2006
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    Densities of aqueous KCl–KBr and NaBr–KBr mixtures are reported from the ionic strengths 0.5 to 4 mol kg−1 of water. The results are analyzed in the light of Pitzer theory of specific interactions. The deviations of experimental quantities from the Young rule (excess volumes) are discussed in terms of interactions between the ions of like charges. The excess volumes showed weak dependence on temperature.
  • T. K. Pal, G. K. Mallik, T. Ganguly, S. B. Banerjee
    1989 Volume 62 Issue 10 Pages 3315-3319
    Published: 1989
    Released: June 27, 2006
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    In the ground state 5,6,7,8-tetrahydro-2-naphthol (ThOH) forms with triethylamine (TEA) simple hydrogen bond, hydrogen-bonded ion pair or solvent-separated ion pair complex depending on the polarity of solvents. Fluorescence emission of ThOH is quenched by TEA in all solvents. The quenching rate constant kq is large in weakly polar solvents than in highly polar solvents and there is no evidence of formation of solvent-separated ion pair in latter solvents. It is suggested that restricted electron delocalization in excited ThOH molecule lowers the tendency of deprotonation of the OH group. The likely pathway of energy depletion is through intermediate singlet contact CT exciplex of the type AD+ between ThOH and TEA.
  • Swapan K. Saha, Prabir Bhattacharya, Mahammad Ali, Pradyot Banerjee
    1989 Volume 62 Issue 10 Pages 3320-3327
    Published: 1989
    Released: June 27, 2006
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    The kinetics of reduction of dodecatungstocobaltate(III) by iminodiacetate (IDA), nitrilotriacetate (NTA), and ethylenediaminetetraacetate (EDTA) have been studied in aqueous solution at 50 °C, 30 °C, and 15 °C respectively. In general, the reactivity of the amine-N-carboxylates is in the order EDTA>NTA>IDA. All the anionic species have been found to undergo oxidation via both a spontaneous and an alkali metal ion-catalyzed pathway, while molecular form of the acids are oxidized only via spontaneous pathway. The rate of oxidation is given by a general expression kox=k°+k[M+]n where kox=kobs/2[L]T([L]T=total concentration of a particular amine-N-carboxylate) and n may have values 1 or 2 depending on the nature of M+. The terms k° and k account for the rate constants of the spontaneous and catalyzed paths respectively. A general trend K+>Na+>Li+ for the catalyzed path has been observed for the oxidation of these amine-N-carboxylates. Reactivities of different species present in the experimental pH range have been evaluated by carrying out experiment at different pH and using these data in appropriate rate expressions. The reactivities (50 °C) of Hida are k°=4.70×10−5 dm3 mol−1 s−1 and k1=3.44×10−4 dm6 mol−2 s−1 for the spontaneous and Na+ catalyzed paths respectively. For NTA oxidation (30 °C), rates are k10°(H3nta)=1.11×10−3 dm3 mol−1 s−1, k11°(H2nta, spontaneous)=7.00×10−3 dm3 mol−1 s−1, k11(H2nta, Na+ catalyzed)=3.50×10−2 dm6 mol−2 s−1, k12°(Hnta2−, spontaneous)=7.20×10−3 dm3 mol−1 s−1, k12(Hnta2−, Na+ catalyzed)=4.01×10−2 dm6 mol−2 s−1. The corresponding reactivities (15 °C) for EDTA oxidation are k20°(H4edta, spontaneous)=6.80×10−3 dm3 mol−1 s−1, k21°(H3edta, spontaneous)=4.80×10−2 dm3 mol−1 s−1, k21(H3edta, Na+ catalyzed)=0.48 dm9 mol−3 s−1, k22°(H2edta2−, spontaneous)=0.21 dm3 mol−1 s−1, k22(H2edta2−, Na+ catalyzed)=1.70 dm6 mol−2 s−1, k23°(Hedta3−, spontaneous)=1.71 dm3 mol−1 s−1, k23(Hedta3−, Na+ catalyzed)=30.00 dm6 mol−2 s−1. A plausible mechanism considering an outersphere association between the complex and reductant has been suggested where the alkali metal ions are assumed to act as a bridge between the reactants.
  • Nanhai Singh, Nand Kishore Singh, Chetna Kaw
    1989 Volume 62 Issue 10 Pages 3328-3333
    Published: 1989
    Released: June 27, 2006
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    A series of heterobimetallic complexes of the form M[M′(Etxant)3] and M[M′(Etxant)3]2 have been prepared by the reaction of K[M′(Etxant)3] [M′=Ni(II), Cd(II), or Pb(II)] and metal nitrate or sulfate [Ma=Co(II), Ni(II), Cd(II), Tl(I), Pb(II), or Ag(I), Etxant=ethylxanthate]. These complexes have been characterized by elemental analysis, molecular weight, molar conductance, magnetic susceptibility, (1H, 13C) NMR, electronic, and infrared spectral studies. Magnetic moment and electronic spectral data indicate square planar geometry around Co(II) or Ni(II), except Tl[Ni(Etxant)3] in which Ni(II) is octahedrally coordinated. NMR spectra of M[M′(Etxant)3]2 clearly indicate the presence of two different ethylxanthate moieties, one attached to the diamagnetic Ni(II), Cd(II), or Pb(II) and the other to the paramagnetic Co(II) centre. Electrical conductance values indicate their nonelectrolytic behavior. Interaction of heterobimetallic complexes with different solvent have been studied and solvent characteristics (donor number, dielectric constant, EB (electrovalent) and CB (covalent) parameters) have been related to the structural properties of the complexes. On the basis of these studies, monomeric structure for M[M′(Etxant)3]2 and polymeric structure for M[M′(Etxant)3] have been suggested.
  • S. N. Balasubrahmanyam, N. Rajendran, D. K. Singh
    1989 Volume 62 Issue 10 Pages 3334-3342
    Published: 1989
    Released: June 27, 2006
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    C-1′, C-1″, C-3, and C-4 13C shifts in 3,4-di(4′-or/and 4″-X)phenyl-1,2,5-oxadiazole 2-oxides (3,4-diarylfurazan 2-oxides; three series: X=NMe2, OMe, Me, Cl, H, and NO2) were correlated vs. seven different divided substituent parameter sets. Results have implied that i) the C-3–C-4 bond does not transmit mesomeric effects efficiently; ii) no effects can be specifically attributed to the possibility that the C-3 aryl maintains a higher dihedral angle with respect to the furoxan ring than the C-4 aryl; iii) there appears to be a directionality to the propagation of localized π-polarization due to lesser ability of C=N(O)→O to convey effects compared with C=N(O); and, iv) the furazan N-oxide ring, being generally an electron acceptor, transmits substituent effects nonlinearly.
  • Puttaswamy, Dandinasivara Siddalingaiah Mahadevappa, Kanchugarakoppal ...
    1989 Volume 62 Issue 10 Pages 3343-3348
    Published: 1989
    Released: June 27, 2006
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    Kinetics of oxidation of indigo carmine (IC) by sodium N-haloarenesulfonamidates (RNXNa, where R=CH3C6H4SO2 or C6H5SO2 and X=Cl or Br) chloramine T (CAT), bromamine T (BAT), chloramine B (CAB), and bromamine B (BAB) in alkaline buffer (pH 9–11) has been followed spectrophotometrically at λmax=610 nm. Rate law, –d[IC]/dt=k[OX]0[IC]0[OH]x where x<1, is obeyed. The reaction products, benzenesulfonamide and toluenesulfonamide retard the rate. Sulfonated anthranilic acid formed was quantitatively determined. Variation of ionic strength or dielectric constant of medium and addition of halide ions have no effect on the reaction. A two pathway mechanism is proposed in which the hypohalous acid (HOX) and the anion of N-haloamine RNX interact with the substrate in rate limiting steps. The rate increases in the order: BAT>BAB>CAT>CAB, which is attributed to the difference in electrophilicities of halogen cations Br+ and Cl+ involved in the oxidation process and the ease with which these species are formed in reactions.
  • D.V. Ramana, N. V. S. Rama Krishna
    1989 Volume 62 Issue 10 Pages 3349-3354
    Published: 1989
    Released: June 27, 2006
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    Oxygen transfers from nitro group to both the sulfur and acetylenic triple bond are noticed in parallel fragmentation pathways during the electron impact induced decompositions of 3-(o-nitrophenylthio)-1-propynes. Single oxygen transfer from nitro group to sulfur leads to abundant ions corresponding to o-nitrosobenzenesulfinyl cation and [M–SO] while a concerted double oxygen transfer to sulfur followed by ejection of SO2 from the rearranged molecular ion affords intense quinoline radical cation. Further, a single oxygen transfer to acetylenic triple bond, followed by a simple cleavage produces intense fragments corresponding to o-nitrosobenzenethiol radical cation at m/z 139 and o-nitrosophenylthio cation at m/z 138. The proposed fragmentation pathways and ion structures are established through high-resolution data, collisioninduced dissociation (CID) mass-analyzed ion kinetic energy (MIKE) spectra, B/E linked scan spectra and chemical substitution.
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