bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption of Dyes, Chromate, and Metallic Ions by Poly(ethyleneimine)
Authors: Sasaki Tsunetaka , Asakawa Osamu , Kurosawa Kazuyo , Mizushima Minoru , Nakazono Teruhiro
Published: July 2006

Ion exchange and chelate properties of poly(ethyleneimine) resin (PEI) were studied. Adsorption of neucoccin anions (NC−) (maximum 1.7×10−4 mol/g) was greater than that of Crystal Violet cations (CV+) (maximum 0.17×10−4 mol/g), indicating that PEI is an anion exchanger. CV+ adsorption increased with the addition of sodium polyacrylate due to its bridging action between CV+ ions and PEI. Adsorption of CrO42− was confirmed to be much greater than that of NC− ions amounting to 4×10−3 mol/g at a sufficiently concentrated solution of CrO42−. The acid exchange capacity of PEI was found to be about the same as the maximum amount of adsorption of CrO42−. Kinetics of adsorption of CrO42− by PEI was studied at various temperatures. Adsorption followed a bimolecular reaction. Activation energy of 28.03×103 J/mol obtained is a right order of magnitude as an ion exchange adsorption. Chelating adsorption of Fe3+ and Cu2+ ions by PEI studied, the maximum amounts of adsorption being 3.1×10−3 mol/g and 3.3×10−3 mol/g, respectively. The values are greater than those for other synthetic polyethylene polyamine. PEI can be used as an anion and metallic cation adsorbent.
A Spectroscopic Study of Hydrogen-bonds Involving the 2-Thiouracil Residue
Authors: Todoriki Hidemi , Nishimura Yoshifumi , Higuchi Shigesada , Hirakawa Akiko Y , Tsuboi Masamichi
Published: July 2006

Infrared absorption spectra, ultraviolet absorption spectra, phosphorescence spectra, phosphorescence lifetimes, and phosphorescence excitation spectra have been examined of 1-propyl-2-thiouracil in various solvents, including CCl4, CH3OH, CCl4+CH3OH, and CCl4+9-ethyladenine. For 1-cyclohexyluracil, and for 2-S-propyl-2-thiouracil, similar infrared spectroscopic examinations were also made. The results obtained are as follows: (1) In CCl4, the 2-thiouracil residue forms a hydrogen-bond complex with the adenine residue, in which the C4=O is involved in the hydrogen-bond. (2) The binding of 2-thiouracil and adenine is much stronger than that of 2-thiouracil and CH3OH; the 2-thiouracil·methanol binding is stronger than the uracil·methanol binding. (3) The hydrogen-bonding of the 2-thiouracil residue (with CH3OH or with adenine) causes an elevation of the lowest singlet excited state S1, which is probably an 1(nπ*), from 2.5×104 cm−1 to 2.6×104 cm−1, and the lowest triplet excited state T15 which is probably an 1(nπ*), from 2.5×104 cm−1 to 2.6×104 cm−1. (4) The hydrogen bonding of the 2-thiouracil residue causes a great enhancement of the phosphorescence intensity. On the basis of these observations, a discussion is given on the nature of the inter-base hydrogen-bonds involving 2-thiouracil residue.
Branched-chain Sugars. XIX. On the Application of 13C NMR Spectroscopy to the Configurational Assignment of 3-C-Substituents of Aldohexopyranose Derivatives
Authors: Sato Ken-ichi , Matsuzawa Masafumi , Ajisaka Katsumi , Yoshimura Juji
Published: July 2006

It was found that 13C NMR spectroscopy is applicable to the unequivocal configurational assignment at the quarternary carbon in seven pairs of 3-C-substituted-hexopyranose derivatives. The configuration of methyl 4,6-O-benzylidene-3-C-nitromethyl-2-O-p-tolylsulfonyl-α-d-glucopyranoside reported by Jordaan et al. is revised to d-allo by a chemical method.
Pressure and Solvent Shifts of Absorption Spectra. II. Intramolecular Charge Transfer Bands
Authors: Sawamura Seiji , Taniguchi Yoshihiro , Suzuki Keizo
Published: July 2006

Absorption spectra of intramolecular CT bands of nitrobenzene, p-nitrophenol, p-nitroaniline, acetophenone, p-hydroxyacetophenone, and p-aminoacetophenone are observed in several nonpolar solvents at 1 bar, and in heptane up to 4400 bar. The fact that all solvent shifts are linearly red for the function of refractive index (n) of solvents, (n2−1)/(2n2+1), consists with the solvent shift theory. On the other hand, the pressure shifts are not straight but convex upward for (n2−1)/(2n2+1) and the red shifts by pressure exceeds the solvent shifts. The similar convex pressure shifts are found in 1Lb bands of several aromatic compounds by plotting the high pressure data of Robertson et al. in spite of the straight solvent shifts in these 1Lb bands measured by us. Therefore the convex pressure shift may be regarded as a general tendency of the electronic spectrum, being ascribed to decrease in the distance between a solute and the surrounding solvents by compression. From comparison with the pressure shift of the intramolecular CT band, it is suggested that, in the pressure shift of the intermolecular CT band of the I2 complexes shifted to red previously, the effect of decrease in the bond distance between a donor and an acceptor proposed by Offen and Nakashima contributes to not a red shift but a blue shift.
Diffusion Coefficients of Bolaform Electrolytes. Part II. Diffusion Coefficients of Magnesium 1,2-Ethanedisulfonate and Magnesium 1,4-Butanedisulfonate in Aqueous Solution
Authors: Uedaira Hisashi , Uedaira Hatsuho
Published: July 2006

The diffusion coefficients of magnesium 1,2-ethanedisulfonate and magnesium 1,4-butanedisulfonate in aqueous solutions have been measured at 25 °C. The concentration dependence of the diffusion coefficients of these salts was larger than those of the corresponding sodium salts. It has been shown that the 2:2 bolaform electrolyte behaves approximately like an ordinary 2:2 electrolyte. From these and previous results, it has been concluded that the diffusion behavior of bolaform electrolytes distinctively depend on the valency of the counterion.
Shapes of the ν1 Band of Liquid Chloroform and Intermolecular Interaction
Authors: Suzuki Tetsuo , Tsutsui Yumiko K , Fujiyama Tsunetake
Published: July 2006

The infrared absorption spectrum for the ν1 fundamental of chloroform or chloroform-d shows strong asymmetry, with a remarkable tailing on the high-frequency side. The observed band-width of the ν1 fundamental of chloroform-d is significantly narrower than that of chloroform. These asymmetric band profiles of the ν1 bands of chloroform and chloroform-d can be interpreted in terms of the existence of two different types of chloroform molecules. One is a molecule which interacts with another molecule, and the other is a non-interacting molecule. The isotope effect on the band-width can be explained in terms of the difference in the reduced mass for chloroform and chloroform-d.
Excess Volumes of Ternary Mixtures
Authors: Kato Masanao
Published: July 2006

An expression for excess volumes of multi-component mixtures was derived, and its applicability to the experimental values of ternary mixtures was demonstrated. It was found, in 1,2-dichloroethane+benzene+cyclohexane, ethanol+benzene+cyclohexane and ethanol+acetone+cyclohexane mixtures, that the agreements between the calculated and the experimental values were satisfactory.
A Study of Electronic Structure of 1,2,4,5-Tetracyanobenzene Anion Radical by Resonance Raman Effect
Authors: Yokoyama Kenji , Maeda Shiro
Published: July 2006

Resonance Raman spectrum of 1,2,4,5-tetracyanobenzene anion radical (TCNB−) was measured and compared with that of the neutral molecule (TCNB). Particularly, a Raman line assigned to C1C2 stretching vibration decreased its frequency remarkably when TCNB was converted to TCNB−. This decrease indicated that the lowest unoccupied molecular orbital (LUMO) of TCNB had a node on C1C2 bonding, showing that the LUMO belonged to an au species. Furthermore vibrational analyses of TCNB and TCNB− were carried out and the assignment of their Raman lines was confirmed.
Synthesis of a Partial Sequence of Proinsulin Using the A-Chain of Natural Insulin. III. Synthesis of a Peptide Corresponding to Positions 41–81 of Bovine Proinsulin
Authors: Aiba Hiroko , Shimonishi Yasutsugu
Published: July 2006

For the synthesis of bovine proinsulin, the S-sulfonate of the Leu–Glu–Gly–Pro–Pro–Gln–Lys[Z(2-Cl)]–Arg–A-chain, which was synthesized using the S-sulfonate of the A-chain of natural bovine insulin and which corresponds to positions 53–81 of bovine proinsulin, was coupled with Boc–Ala–Leu–Glu(OBut)–Leu–Ala–Gly–Gly–Pro–Gly–Ala–Gly–Gly–N3. After removal of the protecting groups from the resulting material the S-sulfonate of the Ala–Leu–Glu–Leu–Ala–Gly–Gly–Pro–Gly–Ala–Gly–Gly–Leu–Glu–Gly–Pro–Pro–Gln–Lys[Z(2-Cl)]–Arg–A-chain, corresponding to positions 41–81 of bovine proinsulin, was purified by chromatography on QAE-Sephadex A-25.
Kinetics of the Formation and Transformation of Alkoxy-derived Strontium Metaborate
Authors: Yamaguchi Osamu , Kamata Muneaki , Shimizu Kiyoshi
Published: July 2006

A new metastable SrB2O4 was formed by heating amorphous material prepared by the simultaneous hydrolysis of strontium and boron alkoxides. Crystallization isotherms were obtained by means of the Avrami equation ln(1−α)=−ktn with n=2, the activation energy being determined to be 351 kJ/mol. The kinetics of transformation of metastable into stable SrB2O4 is interpreted by the first-order equation −ln(1−α)=kt. Activation energies are 498 kJ/mol and 343 kJ/mol for initial and final stages, respectively.
Reactions of Halogeno-bridged Organopalladium(II) Complexes with an Electron-rich Olefin. New Cyclopalladated Carbene Complexes, and (Carbene)chloropalladium(II) Complexes Containing a σ,π-Methallyl Group or a π-Coordinated-chelating Alkyl-Palladium σ-Bond
Authors: Hiraki Katsuma , Sugino Keiichi , Onishi Masayoshi
Published: July 2006

A chloro-bridged organopalladium(II) complex, di-μ-chloro-bis(3-t-butylthio-2-methoxy-2-methylpropyl-1-C,S)dipalladium(II) reacted with an electron-rich olefin, bis(1,3-diphenyl-2-imidazolidinylidene) (L2) to yield a new dinuclear carbene complex, di-μ-chloro-bis(1,3-diphenyl-2-imidazolidinylidenato-2-C,2′-C)dipalladium(II) (4). Complex 4 was treated with thallium acetylacetonate, triisopropyl phosphite, 4-picoline, silver acetate, and L2, affording the corresponding new carbene complexes. On the basis of spectroscopic properties, these complexes were ascribed to new complexes containing cyclopalladated chelate structure in the carbene ligand. Di-μ-chloro-bis(1-3-η3-methallyl)dipalladium(II) and di-μ-chloro-bis(6-exo-methoxy-3a,4,7,7a-tetrahydro-endo-4,7-methanoindene-endo-5σ, 2π)dipalladium(II) reacted with L2 to give new mononuclear (carbene)chloropalladium(II) complexes possessing a σ,π-methallyl group and a π-coordinated-chelating alkyl-palladium σ-bond, respectively.
Synthesis of a Partial Sequence of Proinsulin Using the A-Chain of Natural Insulin. IV. Synthesis of a Peptide Corresponding to Positions 31–81 of Bovine Proinsulin
Authors: Aiba Hiroko , Shimonishi Yasutsugu
Published: July 2006

For the synthesis of bovine proinsulin, the S-sulfonate of the Ala–Leu–Glu–Leu–Ala–Gly–Gly–Pro–Gly–Ala–Gly–Gly–Leu–Glu–Gly–Pro–Pro–Gln–Lys[Z(2-Cl)]–Arg–A-chain, which corresponds to positions 41–81 of bovine proinsulin, was coupled with Boc–Arg(Tos)–Arg(Tos)–Glu(OBut)–Val–Glu(OBut)–Gly–Pro–Gln–Val–Gly–N3. The S-sulfonate of the Arg(Tos)–Arg(Tos)–Glu–Val–Glu–Gly–Pro–Gln–Val–Gly–Ala–Leu–Glu–Leu–Ala–Gly–Gly–Pro–Gly–Ala–Gly–Gly–Leu–Glu–Gly–Pro–Pro–Gln–Lys[Z(2-Cl)]–Arg–A-chain, correspoding to positions 31–81 of bovine proinsulin, was obtained in a pure form by removal of the protecting groups from the coupled product and chromatography on QAE-Sephadex A-25.
Synthetic Photochemistry. XVII. The Singlet-oxygen Oxidation of Vinylcyclopropane in the Presence of Diphenyl Sulfide. The Chemical Reduction of a Dioxetane to a cis-1,2-Glycol
Authors: Hatsui Toshihide , Takeshita Hitoshi
Published: July 2006

The singlet-oxygen oxidation of a spirocyclic vinylcyclopropane in the presence of diphenyl sulfide, a reducing agent, was shown to form a cis-glycol by the O–O cleavage of dioxetane. The determination of the stereochemistry of isomeric glycols obtained by chemical derivation led to a revision of the structure of the azido alcohol formed during the photosensitized oxygenation in a presence of the azide ion to the trans-derivative.
Synthesis of 2,11-Dehydrohomoadamantane (Tetracyclo[5.3.1.02,4.03,9]undecane) and 2,11-Dehydrohomoadamant-4-ene (Tetracyclo[5.3.1.02,4.03,9]undec-5-ene)
Authors: Katsushima Takeo , Maki Ken’ichiro , Yamaguchi Ryohei , Kawanisi Mituyosi
Published: July 2006

Bromination of tricyclo[5.3.1.04,9]undeca-2,5-diene gave endo-2,endo-6- and endo-2,exo-6-dibromotetracyclo[5.3.1.03,5.04,9]undecanes along with syn-11,endo-2-dibromotricyclo[4.3.1.13,8]undec-4-ene (10a) in a ratio of 3:3:1. A thermal treatment of the mixture of these dibromides at 140–150 °C induced a skeletal rearrangement to afford 10a and syn-11,exo-2-dibromotricyclo[4.3.1.13,8]undec-4-ene (10b) in 87% yield (10a:10b=2:5). The new “non-bridgehead” 2,11-dehydrohomoadamantane was obtained by the hydrogenation of 10a and 10b followed by Wurtz type reductive cyclization. The unsaturated analogue, 2,11-dehydrohomoadamant-4-ene was also synthesized from 10a and 10b by the similar cyclization reaction.
The Chemistry of Phenalenium Systems. XXXI. The Synthesis, Dimerization, and Trapping of 6-Methylenebenzo[cd]pyrene
Authors: Hara Osamu , Yamamoto Kagetoshi , Murata Ichiro
Published: July 2006

The acetolysis of 6-mesyloxymethyl-6H-benzo[cd]pyrene (6) gave 7,7a-dihydrospiro[benzo[ghi]perylene-5-(6H),6′-[6H]benzo[cd]pyrene] (13), whereas, on formolysis, 6 gave spiro[benzo[ghi]perylene-5(6H),6′-[6H]benzo[cd]-pyrene], 6-hydroxymethyl-6H-benzo[cd]pyrene, and 6-methyl-6H-benzo[cd]pyrene as well as 13. It might reasonably be supposed that the formation of 13 proceeds in a process involving four steps: (i) the formation of the intermediate 6H-6-benzo[cd]pyren-6-ylmethyl cation (8); (ii) the conversion of 8 into the reactive 6-methylenebenzo[cd]pyrene (5) by the loss of a proton; (iii) the head-to-head self-Diels-Alder dimerization of 5 to the initial dimer, 6,7-dihydrospiro[benzo[ghi]perylene-5(4aH),6′-[cd]benzo[cd]pyrene], and (iv) a 1,3-hydrogen shift to form 13. When 6-methylbenzo[cd]pyren-6-yl tetrafluoroborate (7) was treated with triethylamine in chloroform, the spiro-dimer, 13, was also obtained. The reaction of 7 with triethylamine in the presence of dimethyl acetylenedicarboxylate resulted in the formation of dimethyl benzo[ghi]perylene-5,6-dicarboxylate. These results strongly suggest the intermediate formation of 5 as a reactive compound.
Carbocyclic Ring Formation by the Intramolecular Reaction between Enol Silyl Ether and Allylic Acetate Moieties
Authors: Itoh Akira , Oshima Koichiro , Yamamoto Hisashi , Nozaki Hitosi
Published: July 2006

The title reaction of trans-3-acetoxy-4-(4-methyl-3-trimethylsiloxy-3-pentenyl)cyclohexene proceeds in the presence of Et2AlOAr, where Ar=2,6-di-t-butyl-4-methylphenyl, affording stereospecifically the cis isomer of 2,2-dimethylbicyclo[4.4.0]dec-9-en-3-one. In contrast, the cis-disubstituted cyclohexene compound reacts only sluggishly to produce a mixture of the cis- and trans-fused octalones. Similar stereospecific effect of the allylic double bond configuration on the ease of cyclization has been observed in the synthesis of karahanaenone from 3,7-dimethyl-6-trimethylsiloxy-2,6-octadienyl acetate and related reactions.
New Application of Crown Ethers. III. Synthesis of 4′-Hydroxybenzocrown Ethers and Their Bis(benzocrown ether)s Linked by Poly(oxyethylene) Chain
Authors: Wada Fumio , Arata Ryozo , Goto Tokio , Kikukawa Kiyoshi , Matsuda Tsutomu
Published: July 2006

Baeyer-Villiger oxidation of 4′-acetylbenzocrown ethers followed by alkaline hydrolysis was proved to be a convenient route to 4′-hydroxybenzo-15-crown-5 and -18-crown-6, which formed air-stable hydrated crystals containing three and one mole of water, respectively, on crystallization from the solvent containing a small amount of water. New bis(benzocrown ether)s, connected by poly(oxyethylene) chain, were obtained in good yields by the reaction of the sodium salts with the ditosylates of di-, tri-, tetra-, and pentaethylene glycol.
Kinetic Studies of Co(II)–Malonate, Malate, and Glycolate Complex-formation Reactions in Aqueous Solutions by the Pressure-shock Method
Authors: Harada Shoji , Kawasawa Masuo , Yasunaga Tatsuya
Published: July 2006

A pressure-shock apparatus applicable for the kinetic studies of rapid reactions in solution was constructed and used to study Co(II)–carboxylate complex-formation reactions. The chelate complex-formation reaction was interpreted in terms of a step-by-step mechanism, and the rate constants were obtained. The chelate-ring closing-and-opening process was revealed to be the rate-determining step.
ESR Spectra of Mn(II) Ions in Reversed Micellar Systems
Authors: Sen\={o} Manabu , Sawada Kiyoshi , Araki Koji , Kise Hideo , Iwamoto Kazutoshi
Published: July 2006

ESR spectra of hexaaqua complex of Mn(II) in a hexadecyltrimethylammonium bromide (HTAB)/chloroform reversed micellar system are studied. The structure of the Mn(II) complex is distorted at low water concentrations because of the dehydration due to the lack of water molecules available for the complexes. The effect of dehydration of metal ions on their catalysis for ATP hydrolysis is discussed.
The Photochemical Behavior of 3,3-Dimethyl-1,2-indanedione toward Aromatic Aldehydes
Authors: Maruyama Kazuhiro , Naruta Yoshinori , Osuka Atsuhiro , Suzuki Hitomi
Published: July 2006

The photochemical reaction of 3,3-dimethyl-1,2-indanedione with aromatic aldehydes in benzene was found to give a mixture of two diastereoisomeric 2:2 adducts, a 1:1 adduct, a 2:1 adduct, and pinacol.
Formation of C–S Bond by the Elimination of Perfluorocarboxylic Acid
Authors: Kawa Hajimu , Ishikawa Nobuo
Published: July 2006

Thiirane was readily generated from 2-mercaptoethyl trifluoroacetate or pentafluoropropionate by the intramolecular elimination of the perfluorocarboxylic acid with triethylamine. Alkyl benzyl sulfides were also prepared from benzyl trifluoroacetate or pentafluoropropionate and alkanethiols by the intermolecular elimination of the perfluorocarboxylic acid
Solubility of Some Organic Mercury(II) Halides in Water
Authors: Tajima Kooji , Kai Fumiaki , Kawahara Tetsuo
Published: July 2006

The solubilities of methylmercury(II) chloride (MMC), methylmercury(II) bromide (MMB), methylmercury(II) iodide (MMI), ethylmercury(II) chloride (EMC), and ethylmercury(II) bromide (EMB) in water have been determined over the temperature range of 10–55 °C (20–40 °C for MMC and EMC). The temperature dependence of the solubilities expressed as mole fractions x2 was given by the following equations:

& logx_2(MMC)=-1059/T+0.176 (20–40°C)

& logx_2(MMB)=-1094/T-0.263 (10–55°C)

& logx_2(MMI)=-463/T-3.246 (10–25°C)

& logx_2(MMI)=5.498×10^6(1/T)^2-3.711×10^4(1/T)+57.814 (25–55°C)

& logx_2(EMC)=-1048/T-0.612 (20–40°C)

& logx_2(EMB)=-179/T-4.293 (10–25°C)

& logx_2(EMB)=5.389×10^6(1/T)^2-3.603×10^4(1/T)+55.322 (25–55°C)

The thermodynamic parameters for the transfer process from solid to saturated aqueous solution were also determined.
Kinetic and Spectrophotometric Studies of Rhodamine 6G Dimerization in Aqueous Solution
Authors: Inaoka Wataru , Harada Shoji , Yasunaga Tatsuya
Published: July 2006

The dimerization reaction of dye, Rhodamine 6G, in aqueous solution was studied spectrophotometrically and kinetically: the equilibrium constant and the rate constants were found to be K=1.6×103 M−1, kf=1.1×109 M−1 s−1, and kb=7.0×105 s−1, respectively, at 15 °C. These rate constants, and those of other dyes are discussed. The effect of the ionic strength was also studied.
Thermal Desorption of Hydrogen Adsorbed on Copper Surface
Authors: Kojima Isao , Kiyomiya Makoto , Yasumori Iwao
Published: July 2006

The thermal desorption of hydrogen adsorbed on a clean surface of polycrystalline copper foil was studied under ultra high vacuum conditions. The presence of chemisorbed hydrogen in a dissociated state was verified in a temperature range between 193 and 573 K. During the desorption process, the adsorbed hydrogen atoms recombined into molecules; this follows second order kinetics. The activation energy for desorption was 68.6±8.0 kJ mol−1 and remained nearly constant in the range of surface coverage up to 1.6×1014 atom cm−2. The isotope effect on the desorption of deuterium was found to be straightforward. These findings showed a good agreement with the results obtained from the analysis of H2–D2 equilibration on copper powder catalyst. In addition, the necessary conditions to obtain the exact desorption spectra were inspected with the aid of computer simulation.
The Thermal Unimolecular Decomposition of Methyl Chloride behind Shock Waves
Authors: Kondo Osamu , Saito Ko , Murakami Ichiro
Published: July 2006

The thermal decomposition of methyl chloride diluted in Ar has been studied behind shock waves over the temperature range between 1680 and 2430 K and the total density range of 2.0×10−6–3.5×10−5 mol cm−3. The decomposition rate was monitored by means of the UV absorption of the CH3 radical produced. The initiation reaction was found to be the C–Cl bond fission; the process proceeded in the fall-off region under the present experimental conditions. From the fall-off data, low- and high-pressure rate constants (k0/[Ar] and k∞) were obtained by the application of a refined RRKM theory involving a weak collision effect. Thus, the Arrhenius expressions were given as:

& k_0/[Ar]=10^15.56 exp(-247 kJ mol^-1/RT) cm^3 mol^-1 s^-1,

& k_∞=10^13.86 exp(-383 kJ mol^-1/RT) s^-1.

The collision efficiency factor, βc, was obtained as 0.02 at the mean temperature of the experiment by comparing the low-pressure rate constant with the strong collision-rate constant. The high-pressure rate constant was well explained by the maximum free-energy criterion presented by Quack and Troe.
Homogeneous Hydroformylation of Methyl Acrylate Catalyzed by Co2(CO)8–Di(tertiary phosphine) Complexes
Authors: Murata Kazuhisa , Matsuda Akio
Published: July 2006

Some complexes prepared in situ from Co2(CO)8 and various di(tertiary phosphine)s as ligands have been found to be more active than Co2(CO)8 for the hydroformylation of methyl acrylate. The activity decreased in the order; Ph2P(CH2)2PPh2>Ph2PC≡CPPh2>cis-Ph2PCH=CHPPh2>Ph2P(CH2)3PPh2>none>Ph2PCH2PPh2>Ph2P(CH2)4PPh. The most active catalyst (I) was obtained when a molar ratio of Ph2P(CH2)2PPh2 to Co2(CO)8 was ca. 0.5. The catalyst (I) is also active even at low pressure, where the decomposition of Co2(CO)8 occurs.
Partner Orbitals in Hartree-Fock Theory
Authors: Hirao Kimihiko
Published: July 2006

The orbital ambiguity in the Hartree-Fock theory is removed in such a way as to improve the convergence property of the configuration interaction calculation. A practical proposal is made to obtain efficient orbitals for use in construction of wavefunctions. These orbitals are called the zeroth-order natural orbitals and their partner orbitals. It is also demonstrated by an illustrative calculation that use of partner orbitals rather than SCF orbitals gives much more rapid convergence and greater physical insight.
MO Calculation of Some Aromatic Radicals. Geometry and Spin Density of Benzyl Radical
Authors: Amano Toshihiro , Osamura Yoshihiro , Kai Eiko , Nishimoto Kichisuke
Published: July 2006

The geometry of benzyl radical, nitrobenzene anion-, benzaldehyde anion-, aniline cation-, and phenol cationradicals is optimized by means of the energy gradient method in the framework of the CNDO/2 method, and used for the calculation of spin densities by the INDO-UHF method. The geometrical change from a neutral molecule to the ion radical can be understood by considering the shape of particular MO’s. It was found that the molecular structure of benzyl radical is not a regular hexagon, the contraction of C1–C7 bond being remarkable. The correct order of the spin densities on ortho(ρ2)- and para (ρ4)-positions is obtained by the full geometry optimization. The structure of the deformed ring of benzyl radical is discussed in terms of the orbital mixing rule.
Light Scattering Study of Local Structures in Solutions. Mean Association Numbers and Concentration Fluctuations for Alcohol–Carbon Tetrachloride Systems
Authors: Kato Tadashi , Nakanishi Toru , Fujiyama Tsunetake
Published: July 2006

Light scattering spectra were observed for carbon tetrachloride solutions of methanol, ethanol, and 1-propanol. The Rayleigh intensities were reduced to concentration fluctuations. The observed concentration dependence of the concentration fluctuation was analyzed by using two distinct models: an ideal associated complex (IAC) model and a polymer chain (PC) model. In the IAC model, a group of hydrogen-bonded alcohol molecules is treated as a complex whose size is independent of the association number, l. In the PC model, on the other hand, the group of hydrogen-bonded molecules is treated as a linear polymer whose length is proportional to l. It was shown that the PC model can explain both the concentration fluctuation and the heat of mixing data, while the IAC model cannot be applied to the present systems. The mean association number obtained by the IAC model was discussed on the basis of the relation between the concentration fluctuation and the spatial correlation of microscopic density.
Reaction of Halogenonitrobenzenes with Electro-generated Superoxide Ion
Authors: Sagae Hiromitsu , Fujihira Masamichi , Komazawa Katsutaro , Lund Henning , Osa Tetsuo
Published: July 2006

The reaction of halogenonitrobenzenes (XNBs) with electrogenerated superoxide ion in N,N-dimethylformamide was studied electrochemically using cyclic voltammetry (CV) and controlled potential macro-electrolysis. It was shown in the CV that electro-generated superoxide ion reacts with all of the o- and p-isomers of iodo-, bromo-, and chloronitrobenzene in the dissolved oxygen medium. However the superoxide ion did not react with the other XNBs during CV. Controlled potential macro-electrolysis of oxygen in the presence of o- and p-bromonitrobenzene yielded the corresponding nitrophenols as the main products. The reaction mechanism via nucleophilic attack of the superoxide ion on the XNB, in the preference to an electron-transfer mechanism, is proposed.
Direct Observation of the 1,4-Biradical of Benzophenone with cis-3-Methyl-2-pentene Excited by the Fourth Harmonic of a Nd:YAG Laser
Authors: Hayashi Hisaharu
Published: July 2006

Intermolecular biradical formation between the benzophenone triplet state with cis-3-methyl-2-pentene was studied by a ns laser-photolysis technique, the fourth harmonic (266 nm) of a Q-switched Nd : YAG laser being used as an exciting light source. We succeeded for the first time in observing the transient absorption due to the 1,4-biradical in the 380–300 nm region. Its lifetime was determined to be 25±4 μs (in acetonitrile), 15±4 μs (in methanol), and 6±2 μs (in cyclohexane). Quenching experiments with methyl viologen dication were also carried out in order to assign the observed transient absorptions.
Studies on the Aqueous Solutions of Guanidinium Salts. XIII. NMR Study of the Interactions between Guanidinium Salt and Tetraalkylammonium Salts in Water
Authors: Miyajima Koichiro , Yoshida Hiromitsu , Kuroda Yoshihiro , Nakagaki Masayuki
Published: July 2006

The quadrupole relaxation of 14N nucleus of guanidinium bromide has been measured in aqueous ternary solutions containing symmetrical tetraalkylammonium salts by the 1H NMR method. By means of Pople’s line shape analysis and the Debye-Einstein equation, it has been confirmed that no complex formation takes place in the aqueous ternary solution containing symmetrical tetraalkylammonium salts. The rotational correlation time of the guanidinium ion is linearly related to the absolute viscosity of the solutions containing the homologous series of alkylammonium salts. A similar relationship was obtained for the ternary solutions with sugars or polyethylene glycols. This suggests that the correlation time depends on the microviscosity around the guanidinium ion.
The Use of Grignard Reagents in the Synthesis of Carbohydrates. I. The Synthesis of Deoxy and Branched-chain Deoxy Sugars
Authors: Kawana Masajiro , Emoto Sakae
Published: July 2006

Two branched-chain deoxy sugars, methyl 5,6-O-cyclohexylidene-3-deoxy-2-C-methyl-β-d-arabino-hexofuranoside and its α-d-ribo isomer, were easily prepared by the one-step reaction of methyl 5,6-O-cyclohexylidene-3-O-mesyl-β-d-allofuranoside (3a) with methylmagnesium iodide. Similarly, the corresponding α-mesylate (4a) gave methyl 5,6-O-cyclohexylidene-3-deoxy-2-C-methyl-α-d-ribo-hexofuranoside. It was demonstrated that these reactions involved 1,2-hydride shifts. The reaction of 3a and 4a with t-butylmagnesium bromide yielded two deoxy sugars, methyl 5,6-O-cyclohexylidene-3-deoxy-β-d-arabino-hexofuranoside and the corresponding α-d-ribo isomer, respectively. Under certain reaction conditions with the Grignard reagents, the sulfonate (3a) afforded dimeric compounds, in which two furanose rings were directly bound with a carbon–carbon bond. A convenient method for the preparation of the sulfonates (3a and 4a) is also reported.
Three-dimensional Metal Complex Structures with Ambident Propylene-diamine Ligands Serving as the Hosts of the Aromatic Guest Molecules. Hofmann-pn and pn-Td Type Clathrates
Authors: Nishikiori Shin-ichi , Iwamoto Toschitake , Yoshino Yukichi
Published: July 2006

Novel clathrate compounds, Hofmann-pn type Cd(pn)Ni(CN)4·3/2G (G=C4H5N, C4H4S, or C6H6) and pn-Td type Cd(pn)Cd(or Hg)(CN)4·3/2C6H6, have been prepared. Their host structures are analogous to those of the known Hofmann-en type Cd(en)Ni(CN)4·2G and en-Td type Cd(en)Cd(or Hg)(CN)4·2C6H6. The propylenediamine (pn: 1,2-diaminopropane) molecule ambidently bridges six-coordinate Cd atoms, as the en (ethylenediamine) does in the latter types of clathrates. The guest molecules occupy at random three quarters of the cavities in the host structures: every remaining cavity contains two methyl groups of the pn molecules. The crystal structure of Cd(l-pn)Ni(CN)4·3/2C4H5N has been analyzed in order to demonstrate the structural features. The crystal is tetragonal with the space group P422, a=7.575(2) and c=7.742(2) Å, and Z=1. The degree of disorder is extremely high with regard to the arrangement and orientation of the l-pn molecule.
Non-covalent Interactions in Metal Complexes. II. Induction of Asymmetry in Cobalt(III) Complexes with Amino Acid–Schiff Bases. Importance of CH···π-Interaction in Determining Configuration of Complexes
Authors: Okawa Hisashi , Numata Yoshihiko , Mio Ayako , Kida Sigeo
Published: July 2006

Cobalt(III) complexes, [Co(l-mop=aa)2]− and [Co(cop=aa)2]− (aa=ala−, val−, leu−, phe−), where H2(l-mop=aa) and H2(cop=aa) denote amino acid-Schiff bases of l-menthyl 3-(o-hydroxybenzoyl)propionate and cholesteryl 3-(o-hydroxybenzoyl)propionate, respectively, were prepared in solution. The intensity of the CD peak induced at 520 nm changes with the solvent used for preparation of the complex, decreasing in the order: ethanol, methanol, dimethyl sulfoxide, N,N-dimethylformamide and acetonitrile. Since the order corresponds to the increasing order of the CH···π-interaction between the solvent and benzene, it seems that the CH···π-interaction between the chiral group and the aromatic nucleus in the ligand plays an important role in determining the configuration of the complexes.
The Reaction Process between α-Iron(III) Oxide and Sulfur Dioxide in the Presence of Carbon
Authors: Araki Hiromitsu , Ryoo Young Hong , Eguchi Motonori , Matsuzaki Ryoko , Saeki Yuzo
Published: July 2006

The reaction products obtained by heating a mixture of α-Fe2O3 and carbon in a SO2 stream at various temperatures were examined. The possible reactions during the above process were also examined. The solid products obtained by heating a mixture of α-Fe2O3 and carbon in a SO2 stream were Fe3O4 at 500–700 °C, pyrrhotite and Fe3O4 at 750 °C , and pyrrhotite (Fe0.88S) alone at 800 °C. Sulfur was obtained outside the heating zone throughout the temperature range. The process of the formation of pyrrhotite by the reaction between α-Fe2O3 and SO2 in the presence of carbon can be represented as follows: The reaction between carbon and SO2 occurs even at 350 °C to form sulfur, and the reaction proceeds markedly above ca. 700 °C. Above ca. 500 °C, the reductions of α-Fe2O3 with carbon and sulfur occur to form Fe3O4. Above ca. 750 °C, pyrrhotite is formed by the reaction between Fe3O4 and sulfur. These results were supported by the thermodynamical consideration based on the chemical potential diagram for the Fe–S–C–O system.
Thiocarbonyl Ylide Intermediates Generated by Deprotonation of 2-Phenacylthio- and 2-(p-Bromophenacylthio)-1,3-dithiolylium and 2-(p-Bromophenacylthio)-1,3-dithiolanylium Bromides
Authors: Nakayama Juzo , Takemasa Toshiro , Hoshino Masamatsu
Published: July 2006

2-(p-Bromophenacylthio)-1,3-dithiolylium bromide, when treated with triethylamine, gave 2-(p-bromophenacylidene)-1,3-dithiole (17%) and bis[(p-bromobenzoyl)(1,3-dithiol-2-ylidene)methyl] disulfide (72%). Treatment of 2-phenacylthio-1,3-dithiolylium bromide with triethylamine also gave similar results. On the other hand, 2-(p-bromophenacylthio)-1,3-dithiolanylium bromide yielded 1-(p-bromophenyl)-2-(1,3-dithiolan-2-yl)-2-thioxoethanone (12%) in addition to 2-(p-bromophenacylidene)-1,3-dithiolane (49%) contrary to the reported results. These results can best be rationalized by 1,3-cyclization of thiocarbonyl ylide intermediates to the valence tautomeric episulfides.
Photochemistry of Host–Guest Complex. III. Effect of Guest Cation on the Photoreactivity of Acetophenone Oxime Derivatives Having Crown Ether Moiety
Authors: Tada Masaru , Hirano Hideki , Suzuki Atsushi
Published: July 2006

The syn-anti isomerization of acetylbenzocrown ether oximes was stimulated by the complex-formation with sodium ion. The photolysis of these oximes gave mother ketones and amides through an oxaziridine intermediate. The photolysis of the oximes was depressed by the formation of host-guest complexes. Reactivity in the photolysis of the crown ether oximes corresponds to that of 3,4-dimethoxyacetophenone oxime, whereas the reactivity of the complexed crown ether oxime with sodium ion corresponds to that of p-cyanoacetophenone oxime. Such behavior is explained by the change of the electronic properties of excited states of acetophenone oxime chromophore, which enhances the intersystem crossing.
Stereochemistry of Nucleophilic Addition Reactions. 10. Preparation of 2-C-Diacetylmethyl and 2-C-Acetylmethyl Derivatives with the Altro, Gluco, and Manno Configuration from Methyl 4,6-O-Benzylidene-2,3-dideoxy-3-nitro-α-d-erythro-hex-2-enopyranoside
Authors: Sakakibara Tohru , Seta Akinori , Tachimori Yoshifusa , Sudoh Rokuro
Published: July 2006

Reaction of the title compound with acetylacetone in the presence of a catalytic amount of sodium hydroxide afforded the 2-C-diacetylmethyl and 2-C-acetylmethyl derivatives having the altro, gluco, and manno configurations. The 2-C-diacetylmethyl derivative with the altro configuration exceptionally exists in a skew boat form. The product ratio depends on solvent and the amount of THF.
Synthesis of dl-12,15-Ethylene-13,14-dihydro-prostaglandin-F2α Methyl Ester
Authors: Hamanaka Nobuyuki , Nakai Hisao , Kurono Masayasu
Published: July 2006

A report is given on the synthesis of a spiro prostaglandin analog via triketone obtained by the double Michael addition of 1,3-cyclopentanedione to 1,4-pentadien-3-one.
Reaction of 1,2-Dimethoxybiphenylene with Dichlorocarbene. Chemical Detection of the Bond Fixation in Biphenylene Derivatives
Authors: Sato Masaru , Inaba Keiko , Ebine Seiji , Tsunetsugu Josuke
Published: July 2006

1,2-Dimethoxybiphenylene reacted with dichlorocarbene to give three chloro(methoxy)-6H-benzo[3,4]cyclobuta[1,2]cyclohepten-6-one derivatives, two chloro(methoxy)fluorenones and two dimethoxyfluorenones. The reaction with dibromocarbene gave similar products. The formation of these products serves as unequivocal chemical evidence for bond fixation of 1,2-dimethoxybiphenylene. The chloro(methoxy)-6H-benzo[3,4]cyclobuta-[1,2]cyclohepten-6-one was led to 9-chloro-5-hydroxy-6H-benzo[3,4]cyclobuta[1,2]cyclohepten-6-one, the first tropolone analogue of biphenylene. This compound was shown to exist in only one of the two possible tautomers in contrast with general monocyclic tropolones.
Preferential Solvation of Ag(I) Bromate and Iodate in Dimethyl Sulfoxide–Water Mixtures
Authors: Janardhanan Sivasankaran nair , Kalidas Chatty
Published: July 2006

The selective solvation of Ag(I) bromate and iodate was studied in dimethyl sulfoxide–water mixtures at 30 °C by solubility and EMF measurements. The solubility of silver bromate decreases down to XDmso=0.2 and thereafter increases with addition of dimethyl sulfoxide, the solubility of silver iodate continuously decreasing under the same conditions. The transfer free energy of silver cation decreases while that of halate ions increases with the addition of dimethyl sulfoxide. The solvent transport number, Δ, passes through a maximum around XDmso=0.5 in both cases. These results were interpreted in terms of a heteroselective solvation of both the salts, the silver ion being preferentially solvated by dimethyl sulfoxide and the halate ions selectively hydrated by water in the mixtures.
Polyfunctionality of α-Zr(HPO4)2·H2O. Case of H+/Ag+ and H+/Tl+ Ion Exchange Processes
Authors: Costantino Umberto , Isernia Armando , De Meo Giovanni
Published: July 2006

A detailed investigation of the ion exchange processes of silver and thallium(I) ions on α-Zr(HPO4)2·H2O has been carried out. The H+/Ag+ exchange occurs in AgNO3 or CH3COOAg solution with a single phase transition and leads to Zr(AgPO4)2·H2O (interlayer distance 8.4 Å). The H+/Tl+ ion exchange process has been performed by titrating the exchanger with 0.1 M (TlNO3+TlOH) solution, owing to the great ionic size of Tl(I). The titration curve shows essentially a single plateau. In a similar way to that for H+/Ag+ exchange, the process takes place with a single phase transition, leading to Zr(TlPO4)2·H2O (interlayer distance 9.0 Å). Since the processes are new examples in which a univalent cation is exchanged with a single phase transition in α-Zr(HPO4)2·H2O, the so called “polyfunctionality” of this exchanger has been discussed, considering the high polarizability of Ag+ and Tl+ ions. The catalytic potential applications of zirconium phosphate loaded with Ag+ ions are outlined.
Studies on Synthesis of 6-Bromo-2,3-disubstituted 4(3H)-Quinazolinones and Their Thiones
Authors: Badr Mahmoud Zarif Amin , El-Sherief Hassan Ahmed Hassan , Mahmoud Abdallah Mohamed
Published: July 2006

Synthesis of some 2,3-disubstituted 6-bromo-4(3H)-quinazolinones is described. Treatment of some 4-quinazolinones with phosphorus pentasulfide gave the corresponding 4-quinazolinethiones. The reaction of 6-bromo-2-methyl-3,1-benzoxazin-4-one with hydroxylamine hydrochloride gave 6-bromo-3-hydroxy-2-methyl4(3H)-quinazolinone which on treatment with alkyl halides, acyl chlorides and sulfonyl chlorides gave the corresponding ethers, esters, and sulfonates respectively. 2-Styryl-4(3H)-quinazolinone derivatives are obtained by condensation of aromatic aldehydes and corresponding 3-substituted-6-bromo-2-methyl-4(3H)-quinazolinones. Their antibacterial affinities are of considerable efficiency.
Electronic States of Crystalline Cation Radical Salts. Simple Salt of Phenothiazine+· Br− and Complex Salt of (Phenothiazine)2+· Br−
Authors: Iida Yôichi
Published: July 2006

Phenothiazine forms not only simple cation radical salt of Phenothiazine+· Br− but also complex salt of (Phenothiazine)2+· Br−. In this paper, less-than-half occupied Hubbard model was applied to the complex salt in order to explain its crystal electronic state.
Studies of the Separation Mechanism in Ion-exchange Chromatography. II. Inversion of the Elution Order of Tri- and Divalent Complex Cations with Increasing Concentration of the Eluent
Authors: Yoneda Hayami , Oh Chang Eon , Yamazaki Shigeo
Published: July 2006

Two pairs of tri- and divalent complex cations [Co(en)3]3+, [Ni(en)3]2+ and [Co(phen)3]3+, [Fe(phen)3]2+ were chromatographed through the SP-Sephadex cation-exchange column using various concentrations of aqueous KBr and K2SO4 solutions as eluent, and the inversion of the elution order was observed for the pair of the phen complexes when eluted with KBr and for that of the en complexes when eluted with K2SO4.
Formation of Ketone Diperoxides from Ozonation of O-Methyloximes
Authors: Ito Yoshikatsu , Yokoya Hiroaki , Umehara Yasutoshi , Matsuura Teruo
Published: July 2006

The ozonation of the O-methyloximes has been investigated. Besides the corresponding ketones, ketone diperoxides, and N-methoxyamides were produced. The stereochemistry of the ketone diperoxides was studied by the NMR technique.
Oxidation of Thujopsene with Lead Tetraacetate
Authors: Yokoi Katsumi , Matsubara Yoshiharu
Published: July 2006

We inveatigated the oxidation of thujopsene with lead tetraacetate. In the hydrolysis product, two new sesquiterpenoids were found to be afforded: 6α,10,10-trimethyl-4β-acetyltricyclo[4.4.0.01,3]decane and its C(4)-stereoisomer.
Photocyclization of o-Nitrophenyl Alkyl Ethers
Authors: Oguchi Sh\={o}shichi , Torizuka Hiroshi
Published: July 2006

o-Nitrophenyl alkyl ethers 1a, 1b, and 1c undergo photocyclization to give benzoxazoles 2a, 2b, and 2c, respectively.
Microwave Spectrum of Propyl Silane
Authors: Hayashi Michiro , Nakagawa Jun , Aguni Yasunori
Published: July 2006

The microwave spectra of propyl silane and its four deuterated species were measured. The structure of the antiperiplanar isomer was so obtained as to reproduce the observed moments of inertia. The dipole moment and its direction were determined by Stark-effect measurements of several low J transitions.
Spectroscopic and Kinetic Study of an Intramolecular Aromatic Nucleophilic Photosubstitution. Reaction Mechanism of a Photo-Smiles Rearrangement
Authors: Yokoyama Kenji , Nakagaki Ryoichi , Nakamura Junko , Mutai Kiyoshi , Nagakura Saburo
Published: July 2006

Photo-Smiles rearrangement reaction of N-[ω-(p-nitrophenoxy)alkyl]aniline was studied by measuring the absorption spectra of transient species. Two intermediates A and B were observed and were assigned to a solvated ion pair and the Meisenheimer complex, respectively. The reaction scheme, starting material→intramolecular charge transfer on excitation→A→B→final product, was derived from the relative yields and lifetimes of A and B as well as from the effects of solvent polarity, of triethylamine and oxygen, and of the alkyl chain length on each step of reaction.
On the Origin of Differences in the Phosphorescence Band Patterns of p-Benzoquinone in p-Dihalobenzene Crystals
Authors: Miyagi Yusei , Koyanagi Motohiko , Kanda Yoshiya
Published: July 2006

The phosphorescence spectra of p-benzoquinone (PBQ) have been studied at 4.2 K in isostructural crystals such as p-dichlorobenzene (DCB), p-bromochlorobenzene (BCB), and p-dibromobenzene (DBB); and in their binary mixed crystals. The variable phosphorescence band patterns observed are interpreted in terms of anisotropic local-field effects of the host environmental molecules. A similarity of the phosphorescence intensity distribution between two systems of PBQ/BCB and PBQ/(0.5 molar fraction of DCB+0.5 molar fraction of DBB) is a manifestation of the existence of effective local-fields in the crystals.
Studies on the Preparation of Cuprous Oxide. VIII. A Spectrophotometric Study of Halogenocopper(I) Complexes in Aqueous 5 M Na(ClO4) Solutions
Authors: Sugasaka Kazuhiko , Fujii Ayako
Published: July 2006

The complex formation of copper(I) with bromide and iodide ions in aqueous 5 M (1 M=1 mol dm−3) Na(ClO4) solutions was studied spectrophotometrically over a pH range from acidic to alkaline. Over the concentration range of 0.05–5 M bromide ions in acidic solutions, the CuBr2− and CuBr32− complexes were found. On the other hand, in the iodide system the CuI2−, CuI32− complexes and a higher complex were found under the same experimental conditions, although the composition and the formation constant of the last complex could not be determined in this study. The equilibrium constants for the reactions, CuX2−+X−=CuX32−, were 13 and 1.6 for the bromide and iodide complexes respectively. A hydrolyzed species of copper(I), Cu(OH)2−, was found in an alkaline solution of the two systems. The formation constants, β−22=[Cu(OH)2−][X−]2⁄[CuX2−][OH−]2, were evaluated as follows: β−22=(10.0±0.7)×107([Br−]<2M),(2.6±0.7)×107([Br−]=3M),(1.7±0.7)×107([Br−]=4M) in the bromide solutions, (4.0±0.4)×103 ([I−]<2 M), (2.5±0.4)×103 ([I−]=3 M), (2.2±0.4)×103 ([I−]=4 M) in the iodide solutions.
Voltammetric Studies of Tris(1-pyrrolidinecarbodithioato)manganese(III) and -iron(III) and Bis(1-pyrrolidinecarbodithioato)copper(II) in Nonaqueous Solvents
Authors: Ichimura Akio , Kitagawa Toyokichi
Published: July 2006

The voltammetric behavior of the title complexes has been studied. These complexes give a one-electron oxidation wave and a one-electron reduction wave in most solvents. A linear correlation between the (E1⁄2ox–E1⁄2red) values and the solubility parameters of the solvents was obtained. The (E1⁄2ox–E1⁄2red) values were interpreted in terms of the solvation energy of the complexes.
Deuteration Reaction of Malonate Hydrogens in Some Monomalonatocobalt(III) Compounds
Authors: Sakaguchi Ushio , Nakano Michie , Yoneda Hayami
Published: July 2006

The rate of deuteration at malonate hydrogens has been measured for [Co(mal)(N)4]+ and [Co(malH)(NH3)5]2+ ions in aqueous solution over the pD range of 2 to 8, where mal=malonate dianion, malH=malonate monoanion, and (N)4=(NH3)4, (ethylenediamine)2, (1,3-propanediamine)2, (1,10-phenanthroline)2, or (2,2′-bipyridine)2. For the tetraamine type complexes with a chelated malonate ligand, the deuteration process is acid-catalysed up to pD=about 4 and base-catalysed at higher pD values. This contrasts with the behavior of the unidentate malonate ligand, for which the deuteration is base-catalysed up to pD=3.5, whereupon the deprotonation of the carboxylate group takes place and the deuteration rate steps down to a constant, pH-independent value. The deuteration mechanisms are discussed.
The Kinetics of the β-Cyclodextrin-catalyzed Decarboxylation of Trichloroacetic Acid in an Alkaline Solution
Authors: Motozato Yoshiaki , Furuya Yoshiaki , Matsumoto Toshikazu , Nishihara Tsukasa
Published: July 2006

The rate of the decarboxylation of trichloroacetic acid (abbreviated as TCAH) in the presence of β-cyclodextrin(βCD) in an aqueous solution of sodium hydroxide has been followed by the determination of the remaining TCAH. The rate equation was given by

Rate=(k_1T+k_1TCC_βCD)C_TCAH^1/2+(k_2T-k_2TCC_βCD)C_TCAH.

A probable bimolecular decarboxylation mechanism which involves the unionized molecule of TCAH rather than the anion was proposed and discussed.
Thione S-Imide. Reaction with Heterocumulenes
Authors: Saito Takao , Oikawa Isao , Motoki Shinichi
Published: July 2006

9-Fluorenethione S-p-toluenesulfonimide reacted with diphenylketene to give two regioisomeric 1,3-dipolar cycloadducts. The thione S-imide and symmetrical dialkylcarbodiimides produced 3-tosylimino-1,2,4-thiadiazolidines. In the reaction with ketenimines, there occurred siteselective cycloaddition reactions on C=N vs. C=C bonds in the imines and further rearrangement of the 1,2,4-thiadiazolidine adducts.