bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogen Atom Transfer Reaction through Partial Charge-Transfer Triplet Complex. Chloranil and Mesitylene System
Authors: Kobashi Harumichi , Okada Tadashi , Mataga Noboru
Published: July 2006

Mechanism and kinetics of hydrogen atom transfer reaction from mesitylene (M) to triplet chloranil (3CA) in 1,2-dichloroethane (DCE) at room temperature have been studied by means of picosecond (ps) and nanosecond (ns) laser flash photolysis techniques. It was found that the hydrogen transfer resulting in the formation of chloranil semiquinone radical (CAH·) proceeded through a partial charge-transfer (CT) triplet complex between 3CA and M as an intermediate. No ion-pair formation was observed. The triplet complex showed transient absorption bands in the visible and near infrared regions. The association constant (KT=28 dm3 mol−1) and lifetime (τC=32 ns) of the complex were estimated from a kinetic analysis for 3CA quenching. From these results, combined with those of the quantum yield of CAH· formation, the first order rate constants for the hydrogen transfer and intersystem crossing in the triplet complex were estimated to be (1.7 and 1.4)×107 s−1, respectively.
The Synthesis of 3-Aryl-5-dialkylamino-1,4,2-dithiazol-1-ium Salts
Authors: Shibuya Isao , Yonemoto Katsumi
Published: July 2006

N-(Dialkylthiocarbamoylthio)arenecarboxamides, prepared by acylation of the corresponding S-dialkylthiocarbamoyl-substituted sulfenamides, cyclized with dehydration in a strong acidic media to form a number of 3-aryl-5-dialkylamino-1,4,2-dithiazol-1-ium salts in good yields.
Biomimetic Application of Natural Valinomycin and Nonactine Ionophores to Artificial Transport of Amino Acid Salts
Authors: Tsukube Hiroshi , Takagi Kentaro , Higashiyama Tatsuo , Iwachido Tadashi , Hayama Naomi
Published: July 2006

Biological valinomycin and nonactine ionophores showed new and interesting transport abilities for important amino acid salts in the biomimetic membrane systems, which are of biological interest and of practical significance.
Complex Formation between Heptylviologen and Cyclodextrin
Authors: Kodaka Masato , Fukaya Toshio
Published: July 2006

Complex formation between heptylviologen (1) and cyclodextrins (α and β) was confirmed indirectly. The absorption and circular dichroism (CD) spectra of p-nitrophenolate aqueous solution containing α- or β-cyclodextrin were changed, when 1 was added to the solution. Contrary to 1, methylviologen (3) did not give the spectral changes.
Cyclic Peptides. XXII. Synthesis of [2-Amino-2,3-dehydrobutanoic Acid4]AM-Toxin I
Authors: Mihara Hisakazu , Aoyagi Haruhiko , Ueno Tamio , Kato Tetsuo , Izumiya Nobuo
Published: July 2006

To investigate the role of the side chain of the 2,3-dehydroalanine (ΔAla) residue at position 4 in a cyclic tetradepsipeptide phytotoxin AM-toxin I on necrotic activity for apple leaf, [2-amino-2,3-dehydrobutanoic acid4] AM-toxin I was synthesized by two different routes. This analog showed no toxic activity, indicating that the side chain of the ΔAla residue can not be handled without loss of the activity.
Practical Synthesis of 1,1′-Binaphthyl-2-carboxylic Acids via Side Chain Oxidation of 2-Methyl-1,1′-binaphthyls
Authors: Miyano Sotaro , Okada Shin-ichi , Suzuki Toshiyuki , Handa Shigeru , Hashimoto Harukichi
Published: July 2006

Four 1,1′-binaphthyl-2-carboxylic acids were obtained in 38–53% isolated yield via three-stage oxidation of 2-methyl-1,1′-binaphthyls, that is, i) NBS-bromination to benzylic bromides, ii) treatment with sodium salt of 2-nitropropane to aldehydes, and iii) KMnO4–oxidation to carboxylic acids.
A Convenient Synthesis of (±)-Dimorphecolic Acid and Its Analogs
Authors: Tsuboi Sadao , Maeda Seiji , Takeda Akira
Published: July 2006

Dimorphecolic acid, self-defensive substances in rice plant against rice blast disease, and its analogs were prepared stereoselectively by the reaction of (2E,4Z)-2,4-decadienal with Grignard reagents.
The Formation Process of Hydrous Gallium(III) Oxide Particles Obtained by Hydrolysis at Elevated Temperatures
Authors: Hamada Shuichi , Bando Koji , Kudo Yoshiyuki
Published: July 2006

Hydrous gallium(III) oxide was produced as monodispersed spherical particles by forced hydrolysis in the presence of sulfate ions, though they partially dissolved and recrystallized. The rate of the reaction degree was empirically expressed under the given conditions as dα⁄dt=1.60α2⁄3(1−α)0.874, where α is the reaction degree. Polymeric hydroxo complexes were confirmed to act as precursors of the monodispersed spherical particles, judging from the fractional changes of the monomeric and polymeric species during the hydrolysis. The role of sulfate ions in the formation of hydrous gallium(III) oxide particles was discussed.
Three-Dimensionally-Modified Tetracyanoquinodimethanes and Their Charge-Transfer Complexes with Tetrathiafulvalene Derivatives Having a Wide Range of Ionicity
Authors: Nakasuji Kazuhiro , Nakatsuka Masakatsu , Yamochi Hideki , Murata Ichiro , Harada Shigeharu , Kasai Nobutami , Yamamura Kimiaki , Tanaka Jiro , Saito Gunzi , Enoki Toshiaki , Inokuchi Hiroo
Published: July 2006

Eight different 1:1 charge-transfer(CT) complexes were prepared using tetrahydrobarreleno-tetracyanoquinodimethane(THBTCNQ), dihydrobarreleno-tetracyanoquinodimethane(DHBTCNQ), monobenzobarreleno-tetracyanoquinodimethane(MBBTCNQ), and dibenzobarreleno-tetracyanoquinodimethane(DBBTCNQ) as tetracyanoquinodimethane(TCNQ)-type acceptors, and tetrathiafulvalene(TTF), bis(tetramethyene)-tetrathiafulvalene(OMTTF), and tetramethyl-tetrathiafulvalene(TMTTF) as TTF-type donors. The complexes can be classified into three distinct groups, I–III, on the basis of the magnitude of both the degree of CT and the electrical resistivity of compacted powders. Group-I complexes are characterized by a small band gap semiconductivity and moderate CT, group-II complexes by low conductivity and small CT, and group III complexes by low conductivity and complete CT. The stacking mode of the three groups of complexes are discussed, by comparing the electronic absorption spectra of the three groups of CT complexes with those of the complexes for which the crystal structures are known. A crystal structure analysis of OMTTF–DBBTCNQ revealed that it is the first example of a highly ionic CT complex of a TTF–TCNQ type with a regular mixed stacking mode. These three groups of complexes containing bulky acceptor groups will be of theoretical interest in studying the crystal properties of organic CT complexes.
Mössbauer Spectroscopic Studies of Mercury(II) Chloride Adducts with Binuclear Metallocenes
Authors: Watanabe Masanobu , Motoyama Izumi , Sano Hirotoshi
Published: July 2006

Biferrocene and ferrocenylruthenocene react with HgCl2 to give very stable adducts. Large quadrupole splitting values (2.93 mm s−1 for biferrocene–2HgCl2 and 2.99 mm s−1 for ferrocenylruthenocene–5HgCl2, both at 78 K) indicate the presence of a direct interaction between the Fe and Hg atoms. The stabilities of their adducts suggest a chelating effect between the Fe and Fe or Fe and Ru atoms in biferrocene or ferrocenylruthenocene, respectively.
The Syntheses, Properties, and Crystal and Molecular Structures of the Lanthanoid Mixed-Complexes of O,O′-Diisopropyl Dithiophosphate and Dimethyl Sulfoxide: [Ln{(C3H7O)2PS2}3{(CH3)2SO}2] (Ln=La or Nd), and [Eu{(C3H7O)2PS2}2{(CH3)2SO}3][Eu{(C3H7O)2PS2}4]
Authors: Imai Takashi , Nakamura Masao , Nagai Kiyofumi , Ohki Yoshiyuki , Suzuki Yasuo , Shimoi Mamoru , Ouchi Akira
Published: July 2006

Two types of the mixed complexes indicated in the title have been synthesized, and their crystal and molecular structures of the lanthanum (1) and the europium (2) complexes have been determined by the X-ray diffraction method. Both 1 and 2 are monoclinic, space group P21⁄n, and Z=4. 1, a=17.354(7), b=23.336(4), c=10.955(2) Å, β=96.04(2)°, final R value calculated from 4870 reflections is 0.069; 2, a=29.846(7), b=20.070(3), c=14.057(3) Å, β=92.13(2)°, final R value calculated from 7811 reflections is 0.077. In 1, the central metal atom is octa-coordinated, and is in a dodecahedral geometry, where all O,O′-diisopropyl dithiophosphato ligands (iPr2dtp) span m-edges of the dodecahedron, chelating through both of the respective sulfur atoms. Dimethyl sulfoxide (dmso) ligands occupy the apexes of the other m-edge. In 2, the europium(III) metal atom of the cationic species is hepta-coordinated and is in a pentagonal-bipyramidal geometry where two oxygen atoms of dmso ligate from respective ends of the axis and one oxygen atom of the remaining dmso from the equatorial direction. The central metal atom of the anion is octa-coordinated and is in a dodecahedron; where all m-edges are spanned by iPr2dtp ligands. The solid and the acetonitrile solution of 2 is orange in color due to the charge-transfer band (λmax=415 nm; εmax=1.5×102 dm3 mol(Eu)−1 cm−1).
Isomerism of the Metal Complexes Containing Multidentate Ligands. X. [CoN6]3+-Type Complexes Containing H2N(CH2CH2NH)nH (n=0–4)
Authors: Yoshikawa Yuzo , Kato Nobuyuki , Kimura Yuito , Utsuno Shunji , Natu Gopal N
Published: July 2006

The preparation, separation, and characterization of isomeric complexes of type [CoN6]3+, containing one, two, or three molecules of NH3, en, dien, trien, and tetren (n=0, 1, 2, 3, and 4, respectively for H2N(CH2CH2NH)nH) are reported. All the possible five stereoisomers for [Co(NH3)(en)(dien)]3+ and six stereoisomers for [Co(en)(trien)]3+ have been successfully isolated, but only three of four possible geometrical isomers could be obtained for [Co(NH3)(tetren)]3+. These were characterized by electronic, circular dichroism (CD), and 13C{1H} NMR spectroscopy. Conformational analyses were, also, carried out and the stability, or formation of each isomer at the equilibrium state, is discussed from the calculated strain-energy data and experimental formation ratios.
Organopalladium(II) Complexes Containing Carbon-Bonded Heterocycles as a Ligand
Authors: Isobe Kiyoshi , Nanjo Kazuharu , Nakamura Yukio , Kawaguchi Shinichi
Published: July 2006

Oxidative addition reactions of 2-chloropyridine, 2,6-dichloropyridine, 2-chloropyrazine, and 2-chlorobenzothiazole with tetrakis(triphenylphosphine)palladium(0) gave [{PdCl(R)(PPh3)}2] or trans-[PdCl(R)(PPh3)2] depending on the nature of the carbon-bonded heterocycles R. They are all stable and the chloride ligand is readily replaced by other halides and pseudohalides. These novel organopalladium(II) complexes were characterized by the analytical and molecular-weight data together with IR, 1H NMR and 13C NMR spectra, and the 2-pyridyl-bridged dinuclear structure of [{PdBr(C5H4N-C2)(PPh3)}2] was previously revealed by X-ray analysis. Both of the dinuclear and mononuclear 6-chloro-2-pyridylpalladium(II) complexes catalyze the cross coupling reaction between 2,6-dichloropyridine and methylmagnesium bromide to afford 2-methyl-6-chloropyridine selectively. The mononuclear 6-chloro-2-pyridylpalladium(II) complexes react with carbon monoxide to form the acyl complexes.
Perfluoropropylation of Furans, Thiophenes, and Pyridines with Bis(heptafluorobutyryl) Peroxide
Authors: Sawada Hideo , Yoshida Masato , Hagii Hidehiko , Aoshima Kazuyoshi , Kobayashi Michio
Published: July 2006

Bis(heptafluorobutyryl) peroxide (1) smoothly reacted with furans and thiophenes under mild conditions to regioselectively give 2-perfluoropropylfurans and thiophenes in high yields. Mechanistically, reactions with furans or thiophenes are considered to be initiated by one-electron transfers from substrates to 1. On the other hand, the perfluoropropylation of pyridine was proceeded by the usual free-radical substitution to a pyridinium salt by a heptafluoropropyl radical produced by the homolytic decomposition of 1.
13C and 1H NMR of α-Arylnitrones. Substituent Effects on the α-Position of α-(p-Substituted Phenyl)nitrones
Authors: Yijima Chino , Tsujimoto Toshio , Suda Kohji , Yamauchi Masashige
Published: July 2006

Substituent effects on the 13C and 1H NMR chemical shifts of the α-position of various α-(p-substituted phenyl)nitrones, α-phenyl-N-(1-cyano-2-methylpropyl)nitrones (1), α-phenyl-N-methylnitrones (2), and α-phenyl-N-phenylnitrones (3), have been investigated and the obtained results have been compared with data related to N-(p-substituted benzylidene)anilines (4) and reported data for p-substituted styrenes (5). The chemical shifts of the α-arylnitrones are well correlated with substituent constants by means of a linear combination of two empirical parameters, σi and σπ. Inductive effects predominate at the α-carbon but resonance effects predominate at the α-hydrogen.
X-Ray Photoelectron Spectroscopy of Rare Earth Halides
Authors: Uwamino Yoshinori , Tsuge Akira , Ishizuka Toshio , Yamatera Hideo
Published: July 2006

Rare earth (RE) halides (fluorides, chlorides, bromides, and iodides) have been studied by X-ray photoelectron spectroscopy. The binding energies (BE’s) of the RE 3d and 4d peaks for the chlorides, bromides, and iodides are related to the atomic charge calculated on the basis of Pauling’s scale of electronegativity (Pauling charge). Except for Y and Lu, the observed RE 3d and 4d BE’s for the fluorides are lower than those expected. For Y and Lu, the observed RE 3d and 4d BE’s for all halides are related to the Pauling charge. For the fluorides and chlorides, the BE’s of the ligand peak show variations with increasing atomic number of RE’s and a specific “tetrad effect” is observed in plots of BE versus RE atomic number and versus 1/R (where R is the mean distance from the ligand atom to the neighboring RE atom), except for the BE’s of the F 1s peaks from the light RE fluorides. For the iodides and bromides, no or little characteristic variations are seen in the BE’s of I and Br.
Catalytic Action of Iron and Manganese Ions in the Photochemically-Induced Oxidation of d-Fructose with Atmospheric Oxygen
Authors: Araki Koji , Shiraishi Shinsaku
Published: July 2006

d-Fructose is susceptible to photochemically-induced oxidation by atmospheric oxygen in the presence of a catalytic amount of iron or manganese cations in a neutral to weakly basic pH range. Metal hydroxide does not precipitate from a solution in this pH range because of the high sequestering ability of d-fructose. Upon irradiation of Pyrex-filtered light, d-fructose degraded into d-erythrose and other fragments. This reaction is shown to proceed by coupling with an oxidation-reduction cycle involving a metal cation, i.e., the photooxidation of d-fructose by M(III) and the subsequent reoxidation of the resultant M(II) by atmospheric oxygen.
Kinetics and Mechanism of the Extraction of Nickel(II) with 3-Mercapto-1,5-Diphenylformazan in the Presence of 1,10-Phenanthroline or Pyridine
Authors: Ohashi Kousaburo , Shoji Hidetoshi , Yamamoto Katsumi
Published: July 2006

The kinetics and mechanism of the extraction of nickel(II) with 3-mercapto-1,5-diphenylformazan (dithizone, Hdz) into chloroform in the presence of 1,10-phenanthroline (phen) or pyridine (py) were studied in the presence of 0.1 mol dm−3 or 0.2 mol dm−3 NaNO3 at 25 °C. For the nickel(II)–dithizone–1,10-phenanthroline system, the rate-determining steps were the competitive reactions of nickel(II) with dithizonate and with 1,10-phenanthroline in an aqueous phase. The second-order rate constants for the formation of [Ni(dz)]+ and of [Ni(phen)]2+ were determined to be (6.0±0.4)×103 mol−1 dm3 s−1 and (3.4±0.2)×103 mol−1 dm3 s−1 respectively. It was suggested that [Ni(phen)]2+ is more reactive toward dithizonate than toward 1,10-phenanthroline in an aqueous phase. The formation of [Ni(phen)2]2+ retards the extraction of nickel(II) with dithizone. For the nickel(II)–dithizone–pyridine system, the rate-determining step is probably the reaction of [Ni(py)]2+ with dithizonate in an aqueous phase. The second-order rate constant for this reaction was determined to be (1.7±0.3)×105 mol−1 dm3s−1.
The Crystal and Molecular Structure of Bis(4-methylpyridine)bis(thiocyanato)cadmium(II) in Polymeric Form, [Cd(SCN)2(CH3C5H4N)2]n
Authors: Taniguchi Masahiro , Shimoi Mamoru , Ouchi Akira
Published: July 2006

The crystal and molecular structure of the title complex was determined by a single-crystal X-ray diffraction technique. The crystal is triclinic with a space group P\bar1, a=11.323(4), b=18.383(10), c=9.284(5) Å, α=104.62(4), β=114.26(3), γ=77.71(4)°, Z=4; the final R value obtained was 0.034. All cadmium atoms are lined approximately along the [111] axis and each pair of metal atoms are bridged by two thiocyanate ions (SCN), one of which is S-coordinated and the other is N-coordinated to the same side metal atom. Also bonded with two nitrogen atoms of 4-methylpyridine (pic) ligands, the metal atom is 4N2S-hexa-coordinated and is in an octahedral geometry. The cadmium atoms, where the ligated respective pairs of N(SCN), N(pic), and S(SCN) atoms are all in a trans configuration, and the metal atoms where the ligated respective pairs of N(pic) and S(SCN) are in cis, while the pair of the N(SCN) in trans configuration, appear alternatively in the polymer chain.
ESR Study of Radical Halogen Abstractions. Participation of Electron-Transfer Mechanism in the Radical Halogen Abstractions
Authors: Kuwae Yoko , Kamachi Mikiharu , Hayashi Koichiro , Viehe Heinz G
Published: July 2006

The halogen-abstraction reactions of carbon radicals were investigated as a model of the chain-transfer reaction in the radical polymerization of vinyl compounds. The kinetics of the halogen-abstraction reaction of carbon radicals ((CH3)2\dotCX, X=OC6H5, OCOCH3, SC6H5, C6H5, and CN) from tetrahalomethanes(CBr4, CBrCl3, CCl4) were studied in toluene at 80 °C by the ESR method using 2-(t-butyl)thioacrylonitrile as a spin-trapping reagent. The reactivity of these radicals for each halomethane decreased in the order X: OC6H5>OCOCH3>SC6H5>C6H5>CN The reactivity of tetrahalomethanes for each radical decreased in the order CBr4>CBrCl3>CCl4. Results are explained by taking into account the electron-transfer process from carbon radicals to tetrahalomethanes. Absolute rate constants of the halogen abstraction of (CH3)2\dotCCN and (CH3)2\dotCC6H5 from CBr4 and CBrCl3, and of their additions to 2-(t-butylthio)acrylonitrile were estimated by the spin-trapping method, and they were compared with available data for similar reactions.
Microheterogeniety in Aqueous Mixtures of Hydrophobic Solutes through Viscosity Studies
Authors: Ramanamurti M V , Prabhu P V S S , Bahadur S L
Published: July 2006

Precise viscosity data for aqueous binary mixtures of ethylene glycol (EG), 2-methoxyethanol (ME), and 1,2-dimethoxyethane (DME) at different mole fractions and at various temperatures are presented. EG behaves as a structure breaker showing negative deviation in viscosity–composition curve. Hydrophobic solutes ME and DME showed typical maximum in viscosity–composition curve in water rich region; attributed to the existence of “microheterogeniety” in these mixtures.
Solvent Effect on Lifetime of Triplet Exciplex between Chloranil and Durene
Authors: Kobashi Harumichi , Kondo Tomoyuki , Funabashi Masa-aki
Published: July 2006

The triplet exciplex between chloranil (CA) and durene (DH) shows a decay which is associated with solvent viscosity rather than polarity, in spite of having a full charge-transfer (CT) character.
The Asymmetric Ullmann Coupling Reaction of (S)-2,2′-Bis(1-bromo-2-naphthoyloxy)-1,1′-binaphthyl Revisited. Formation of 24-Membered Optically Pure Cyclic Dimer as Well as 12-Membered Cyclic Monomer
Authors: Miyano Sotaro , Handa Shigeru , Tobita Masayuki , Hashimoto Harukichi
Published: July 2006

The copper-promoted Ullmann reaction of the title diester proceeded with high stereoselectivity to give 24-membered optically pure cyclic dimer of (S,S,S,S)-configuration as well as 12-membered monomeric cycle of (S,S)-configuration. The reaction also gave reduced, open-chain dimer enriched in (S,R,S)-diastereomer over (S,S,S)-counterpart (17% d.e.). Stereochemical course to the cyclic dimer was discussed considering the result that the intermolecular Ullmann coupling of chiral alcohol esters of 1-bromo-2-naphthoic acid poorly induced axial chirality in the joining of the two naphthyl units.
The Determination of a Small Amount of Biological Constituent by the Use of Chemiluminescence. VII. An Attempt of Cyclic Immunoaffinity Chromatography
Authors: Hara Tadashi , Toriyama Motohiro , Ebuchi Takashi , Imaki Masakatsu
Published: July 2006

An immunoaffinity chromatography has been established by combining a chemiluminescence detector developed by the authors with two kinds of immunoaffinity columns connected in series. According to the present method, human serum albumin and ovalbumin in the range of 100 ng to 15 μg in their mixtures could be continuously and selectively determined.
Electrochemistry of the Redox-Active Langmuir–Blodgett Films Coated on Glassy Carbon Electrodes
Authors: Fujihira Masamichi , Araki Toshinari
Published: July 2006

In order to study the electrochemical behavior of a redox species in the Langmuir–Blodgett (LB) film on a glassy carbon (GC) electrode, three kinds of amphiphilic redox compounds, each carrying an anthraquinone, a viologen, and a ferrocene moiety, were confined on the electrode surfaces. Prior to the deposition of the film on the electrode, surface pressure–area isotherms for a number of mixed films of the redox-active amphiphiles and arachidic acid were recorded and the stability of the monolayers was discussed. Finally, the cyclic voltammetric behavior of the LB film-modified electrodes was discussed in terms of the changes in the structure and the nature of the LB film caused by the redox reactions.
Mössbauer and DTA Studies of Superionic Conducting AgCl–Ag2O–B2O3 Glasses
Authors: Nishida Tetsuaki , Ogata Michiko , Takashima Yoshimasa
Published: July 2006

A structural study of silver borate glasses containing 20 or 30 mol% AgCl and 1 mol% Fe2O3 has been performed by means of Mössbauer spectroscopy. The distinct decreases in the Mössbauer parameters observed in the borate glasses with Ag2O contents higher than about 10 mol% suggest that chloride ions are covalently bonded with tetrahedral iron or boron atoms as nonbridging chlorine. On the other hand, chloride ions are considered to be ionically bonded with Ag+ ions at the interstitial sites of the three-dimensional network composed of BO3, BO4, and FeO4 units when the Ag2O content is lower than 10 mol%. Measurements of the glass transition temperatures and the electric conductivity show a good agreement with the Mössbauer results, suggesting that mobile and electric conducting Ag+ ions change their configurational sites from the interstitial sites which are close to Cl− ions to different interstitial sites which are close to the nonbridging chlorine atom.
Calorimetric and Spectrophotometric Studies of Copper(II) Chloro Complexes in Dimethyl Sulfoxide
Authors: Ishiguro Shin-ichi , Suzuki Honoh , Jeliazkova Bojana G , Ohtaki Hitoshi
Published: July 2006

Complex formation equilibria between copper(II) and chloride ions have been studied by calorimetric and spectrophotometric titrations in dimethyl sulfoxide (DMSO) containing 0.2 mol dm−3 (C2H5)4NClO4 or 1 mol dm−3 LiClO4 as a constant ionic medium at 25 °C. Both calorimetric and spectrophotometric data obtained were well explained in terms of formation of [CuCln](2−n)+ (n=1–4) in each solution, and their formation constants, enthalpies and entropies were determined. It was found that the complexation at each step was appreciably suppressed in the LiClO4 DMSO solution compared to that in the (C2H5)4NClO4 one, which was ascribed to the extensive formation of LiCl ion-pairs in the former solution. As well as in N,N-dimethylformamide (DMF), positive values of stepwise ΔHn° and ΔSn° (n=1–3) and negative ΔH4° values were observed in DMSO. However, the ΔSn° (n=1, 2, and 4) values in DMSO were appreciably smaller than the corresponding ones in DMF. The result was interpreted in terms of stronger intermolecular interactions in the bulk DMSO than those in DMF. The entropies of transfer of [CuCln](2−n)+ (n=0–4) from DMF to DMSO were significantly positive. This result also suggested that DMSO is a highly associated solvent. Electronic spectra of individual copper(II) chloro complexes were extracted from the spectra measured by varying molar ratios of chloride to copper(II) ions in solution. In contrast to the electronic spectra of Cu2+, [CuCl]+ and [CuCl2], the spectra of [CuCl3]− and [CuCl4]2− in DMSO were not appreciably different from those in DMF, indicating that solvation of these complexes are rather weak in both solvents.
Design of the Synthetic Route for Peptides and Proteins Based on the Solubility Prediction Method. I. Synthesis and Solubility Properties of Human Proinsulin C-Peptide Fragments
Authors: Narita Mitsuaki , Ogura Toshihiko , Sato Kazuhiro , Honda Shinya
Published: July 2006

The usefulness of the solubility prediction method is demonstrated using relatively small peptide fragments of human proinsulin C-peptide. The propriety of the solubility prediction method for peptides having polar side chains is also examined in the following respects: (1) Peptide intermediates smaller than a heptapeptide have high solubility regardless of their  values; (2) the  values of peptide intermediates are useful for judging solubility of peptide intermediates equal to or larger than an octapeptide level; (3) the Pro residue in a central position of a peptide chain is effective for increasing peptide solubility; and (4) there is critical chain length for peptide insolubility caused by a β-sheet aggregation. A strategy suitable for the design of the synthetic route for human proinsulin C-peptide is subsequently discussed on the basis of the solubility prediction of peptide intermediates.
Infrared Absorption Study of Human Proinsulin C-Peptide Fragments in Dichloromethane
Authors: Narita Mitsuaki , Ogura Toshihiko , Sato Kazuhiro , Honda Shinya
Published: July 2006

In connection with the relationship between the conformation and solubility of peptide intermediates having polar side chains, IR spectroscopic conformational analysis of human proinsulin C-peptide fragments was performed in dichloromethane. The polar amino acid residues involved in the peptide fragments are Glu(OBzl), Asp(OBzl), Gin, and Ser(Bzl). Especially, the N–H stretching absorption spectra have been explored over a wide range of concentration. Based on the concentration dependence of the N–H stretching bands, it has been shown that the characteristic N–H stretching band around 3330 cm−1 is due to the intramolecular hydrogen bond. Intermolecular hydrogen bonding also occurs to a small extent in these peptides, giving rise to a slight concentration dependence of the N–H stretching bands. Conformational behaviors of oligopeptides having protected polar side chains of the Glu(OBzl) and Asp(OBzl) residues are just the same as those of the corresponding homooligo(Leu)s, indicating that the protected polar side chains do not disturb conformational behaviors of the oligopeptides. Conformational analysis of the peptide in dichloromethane, which contains the Pro residue and has a high potential for the formation of an α-helical structure, distinctly suggests that the Pro residue near the N-terminal in the peptide has the great ability to promote successive intramolecular hydrogen bonds, probably corresponding to the α-helical structure of the peptide.
A Diels–Alder Cycloaddition and Electrocyclization Sequence as a New [6.5] Annelation Method to Benzene Ring
Authors: Wada Eiji , Kanemasa Shuji , Tsuge Otohiko
Published: July 2006

The Diels–Alder reactions of 1-aryl-2-methylene-3-buten-1-ols, readily available from chloroprene and aryl ketones, with olefinic dienophiles and subsequent electrocyclic reactions of the cycloadducts offer a new method of [6.5] annelation to benzene ring. By this way, tetrahydrofluorene skeletons bearing functional groups can be prepared. Stereochemical aspect of this sequence is also discussed.
Novel Regioselective Iodination of Estradiol 17β-Acetate
Authors: Horiuchi C Akira , Haga Akinori , Satoh J Yasuo
Published: July 2006

Direct iodination of estradiol 17β-acetate (3) using iodine–copper(II) acetate in acetic acid afforded the 2-iodo derivative regioselectively in high yield. The iodination of 3 using several methods was discussed. On the other hand, the reaction of 3 with iodine–copper(II) bromide gave the 4-bromo derivative (7), not the 2-iodo compound. The reaction of 3-methoxy-17β-acetoxy-1,3,5(10)-estratriene (4) with iodine–copper(II) chloride–iron(III) chloride in acetic acid gave the 2- (10) and 4-iodo (11) derivative.
[2+4] and [6+4] Type Cycloaddition Reactions of 1-Ethoxycarbonyl-1H-azepine and 1-Ethoxycarbonyl-1H-1,2-diazepine with 3,4,5,6-Tetrachloro-1,2-benzoquinone
Authors: Saito Katsuhiro , Mukai Toshio , Iida Shigenori
Published: July 2006

The reaction of 1-ethoxycarbonyl-1H-azepine with 3,4,5,6-tetrachloro-1,2-benzoquinone at room temperature gave a [6+4]-type cycloadduct as the major product and two kinds of [2+4]-type cycloadducts. In this reaction the diketone moiety of the benzoquinone derivative was used as the 4π component to form ether linkages. The [6+4]-type cycloadduct became rearranged to one of the [2+4]-type cycloadducts by heating at 90 °C. The same reaction, but using 1-ethoxycarbonyl-1H-1,2-diazepine, afforded two kinds of [2+4]-type cycloadducts. An electronic attraction between the oxygen atoms of the benzoquinone derivative and the carbons in the 2 and 7-positions of the azepine derivative is considered to be one of the driving force of the [6+4]-type cycloaddition reaction. The [2+4]-type cycloadducts are regarded to be formed via inverse electron demand Diels–Alder reactions.
Structures of Agelasines, Diterpenes Having a 9-Methyladeninium Chromophore Isolated from the Okinawan Marine Sponge Agelas nakamurai Hoshino
Authors: Wu Houming , Nakamura Hideshi , Kobayashi Jun’ichi , Kobayashi Masaki , Ohizumi Yasushi , Hirata Yoshimasa
Published: July 2006

Novel diterpenes, agelasine-A, -B, -C, -D, -E, and -F were isolated from the Okinawan marine sponge Agelas nakamurai Hoshino and their structures were established to be monocyclic and bicyclic diterpenes having a 9-methyladeninium unit by spectral analyses and chemical transformations.
Insertion of Sulfur Trioxide into the N–Si Bond of Anilinotrimethylsilane. An Improved Method for the Preparation of Free Phenylamidosulfuric Acid
Authors: Kanetani Fujio , Okada Eiji , Negoro Kenji
Published: July 2006

The reaction between anilinotrimethylsilane (1) and a variety of sulfonating agents [SO3, ClSO3H, trimethylsilyl chlorosulfate (5), dioxane–sulfur trioxide complex, ethyl chlorosulfate (10)] has been studied. With SO3, 5, or a dioxane–sulfur trioxide complex a sulfur trioxide molecule was inserted selectively into the N–Si bond of 1 to yield trimethylsilyl phenylamidosulfate (2), which on treatment with acetic acid, trifluoroacetic acid, or methanol gave free phenylamidosulfuric acid (3). The reaction of 1 with ClSO3H afforded 3 directly, but the product was contaminated with slight amounts of anilinium hydrogensulfate and anilinium chloride. The reaction of 1 with 10 yielded a mixture containing dianilinium (4-sulfonatophenylamido)sulfate, 4-aminobenzenesulfonic acid, and ethyl phenylamidosulfate as major products (after desilylation). The reaction of 1 with 5 has been found to provide an improved method for preparing 3.
Synthetic Versatility of N-(Silylmethyl)imines: Water-Induced Generation of N-Protonated Azomethine Ylides of Nonstabilized Type and Fluoride-Induced Generation of 2-Azaallyl Anions
Authors: Tsuge Otohiko , Kanemasa Shuji , Hatada Akira , Matsuda Koyo
Published: July 2006

N-(Silylmethyl)imines generate N-protonated azomethine ylides of nonstabilized type when treated with water in HMPA, which undergo stereospecific and regioselective cycloadditions with electron-poor olefins affording N-unsubstituted pyrrolidines. On the other hand, fluoride-induced desilylation of the imines leads to 2-azaallyl anions which are found to be synthetic equivalents of aminomethyl anion in the Michael additions with electron-poor olefins and nucleophilic additions with carbonyl compounds.
Photocatalytic Isomerization of Butenes over TiO2. Photo-Formed Active Species and Characteristics of Reaction
Authors: Anpo Masakazu , Yabuta Masaaki , Kodama Sukeya , Kubokawa Yutaka
Published: July 2006

It has been found that UV irradiation of powdered TiO2 catalysts in the presence of butene molecules leads to both cis-trans and double bond shift isomerization reactions with high efficiency. In the photocatalytic isomerization the reactivity of 2-butene is much higher than that of 1-butene, being in contrast to the feature in the thermal isomerization. The addition of O2 or NO molecules leads to the complete inhibition of photocatalytic isomerization of butenes. The effect of adsorbed water on the photocatalytic isomerization has been investigated. From these results together with the ESR measurements under UV irradiation of TiO2 at 77 K in the presence of butene as well as O2 or NO, the following conclusion emerges: The interaction of the photo-formed O− species or [Ti3+–O−] pairs results in opening of the C=C bond of butene, i.e. formation of a radical species, which acts as the intermediate in the photocatalytic isomerization. The O− as well as surface OH− species participates in the hydrogen shift, i.e. the double bond shift isomerization. Thus, the reaction mechanism which has been proposed for the photocatalytic isomerization of butene over ZnO has been confirmed over TiO2.
Syntheses and Properties of Copper(II) Triperchlorates with N,N′,N″,N'″-Tetrakis(2-aminoethyl)-1,4,8,11-tetraazacyclotetradecane and an Anion
Authors: Kida Sigeo , Murase Ichiro , Harada Chizu , Daizeng Liao , Mikuriya Masahiro
Published: July 2006

Copper complexes of the title ligand (taec) of the general formula Cu2(taec)X(ClO4)3 (X=F, Cl, Br, I, HCOO, CH3COO, NO2) were prepared and characterized. The formation constants for [Cu2(taec)]4++X−=[Cu2(taec)X]3+(X=F, Cl, Br, I) were determined spectrophotometrically in aqueous solution. The stabilities of the halogen-copper bonds were greatly enhanced relative to those of ordinary halogenocopper complexes, the order of the formation constants being Cl>Br>I>F. This result can be explained as that the anion is trapped in a cavity formed by two copper ions and the methylene chains of taec molecule, thereby the stability of the bound anion is enhanced and the fitness of the size of anion to the cavity is the most important factor for the formation constant.
Nonsteroidal Antiinflammatory Drugs. V. The Crystal and Molecular Structure of (±)-(2S*)-2-[4-((1S*,2R*)-2-hydroxycydopentylmethyl)phenyl]propionic Acid
Authors: Hata Tadashi , Sato Sadao , Tamura Chihiro
Published: July 2006

The crystal structure of the title compound was determined by X-ray diffraction techniques and was refined to a final R index of 0.094 for 1249 reflections. The cyclopentane ring takes a half-chair conformation in which the two substituents are attached at equatorial positions. The molecules form centrosymmetric tetramers by the two hydrogen bonds through the carboxyl and hydroxyl groups.
Preparation of Organocaldum Halides Using Calcium Ultrafine Particle
Authors: Mochida Kunio , Ogura Sei-ichi , Yamanishi Takayuki
Published: July 2006

Organocalcium halides were prepared from organic halides and calcium ultrafine particle in good yields.
An 1H NMR Study on the Motion of Guanidinium Cations in Some Crystals Formed with Tetrahedral or Octahedral Complex Anions Having Halide Ions as Ligands
Authors: Furukawa Yoshihiro , Nakamura Daiyu
Published: July 2006

The temperature dependences of 1H NMR spin-lattice relaxation times were determined at 20 MHz for [C(NH2)3]2ZnX4 (X=Cl, Br), [C(NH2)3]2MCl6 (M=Sn, Te, Pt), and [C(NH2)3]2PtBr6. Above room temperature, the D3h cation undergoes reorientational motion by 120° about the cationic C3 axis. For [C(NH2)3]2TeCl6 crystals, two phase transitions were located at 312 and 373 K.
Vacuum Sublimation Behavior of Iron(III), Cobalt(II), Nickel(II), Copper(II), and Palladium(II) Chelates with Tetradentate N,N′-Disalicylideneethylenediamine and N,N′-Bis(1-methyl-3-oxobutylidene)ethylenediamine
Authors: Honjo Takaharu , Nukui Kazuhiko
Published: July 2006

A vacuum sublimation apparatus with a continuous temperature gradient (25–200°C) along the tube (50–0cm) at 2×10−2 Torr (1 Torr=133.322 Pa) was used. N,N′-disalicylidenmhylenediamine, N,N′-bis(1-methyl-3-oxobutylidene)ethylenediamine and its metal chelates (FeIII, CoII, NiII, CuII, and PdII) were sublimed without thermal decomposition, while the chelates of FeIII, CoII, NiII, CuII, and PdII with N,N′-disalicylideneethylenediamine were thermally stable, but did not sublime completely.
Preparation and Characterization of Nickel(II) Complexes with Diethyl N,N′-Ethylenebis(2-hydroxyimino-3-iminobutanoate) and Its Analogue
Authors: Kim Soo Han , Okamoto Ken-ichi , Einaga Hisahiko , Hidaka Jinsai
Published: July 2006

The reaction of nickel(II) chloride hexahydrate and ethyl α-(hydroxyimino)acetoacetate with ethylenediamine or (R)-propylenediamine gives [diethyl N,N′-ethyIenebis(2-hydroxyimino-3-iminobutanoato)]nickel(II) or {diethyl N,N′-[(R)-1-methylethylene]bis(2-hydroxyimino-3-iminobutanoato)}nickel(II). The nickel(II) complexes with Schiff base ligands were characterized by their electronic absorption, 13CNMR, infrared, and CD spectra.
Optical Resolution of Asymmetric Selenoxides by High-Performance Liquid Chromatography Using Optically Active Column
Authors: Shimizu Toshio , Kobayashi Michio
Published: July 2006

The optical resolution of asymmetric diaryl selenoxides and the determination of the enantiomeric excess of the partially active selenoxides were found to be possible by HPLC using an optically active column.
Racemic Structures and Optical Resolution by Preferential Crystallization of Organic Ammonium Salts of (±)-Mandelic Acid
Authors: Shiraiwa Tadashi , Nakamura Mitsuhiro , Nobeoka Masanobu , Kurokawa Hidemoto
Published: July 2006

According to a thermodynamic analysis the 4-methylpiperidinium salt of (±)-mandelic acid is a conglomerate around room temperature, though the salt forms a racemic compound in the vicinity of the melting point. A successive preferential crystallization in ethanol at 10°C yields both the (+)- and (−)-salts with optical purities of over 95%.
The Point of Zero Charge and the Isoelectric Point of γ-Fe2O3 and α-Fe2O3
Authors: Watanabe Haruo , Seto Jun’etsu
Published: July 2006

The difference of the point of zero charge (PZC) and isoelectric point (IEP) values for γ- and α-Fe2O3 were measured and are quantitatively explained by the difference in crystal structure. Great care was taken to assure the purity of the samples and that measurements were taken under identical conditions. The PZC and the IEP for the “unhydrated” samples, were the same for each crystal structure, with the values for γ-Fe2O3 being more acidic, by 1.1 or 1.2 pH units, than for α-Fe2O3. This difference can be quantitatively explained by Parks’ equation, in terms of the difference in the coordinations of the Fe3+ ions in the two crystal structures.
Transport Properties of Cation-Exchange Membrane–Aqueous Electrolyte System
Authors: Nagata Yoshihiko , Kohara Kazuyuki , Yang Wong Kang , Yamauchi Akira , Kimizuka Hideo
Published: July 2006

Transport properties of a cation-exchange membrane-aqueous sodium chloride solution system have been studied. The membrane used was a sulfonated styrene–divinyl benzene copolymer, Neosepta C66-5T. The salt concentration was kept at 10−1 mol dm−3 on one side of the membrane and varied from 10−3 to 10−2 mol dm−3 on the other. The six elements of a conductance matrix have been experimentally determined according to the previous theory and the membrane properties were discussed in terms of conductance elements. All the elements of the conductance matrix were positive within the concentration range studied. This would be characteristic of a cation-exchange membrane. The electrical ion conductance was greater than the diffusional ion conductance by a factor of 10 to 100. The ion-solvent coupling coefficient was much less than the interionic one, although the electroosmotic conductance was ten-times greater than the membrane conductance. The reflection coefficient was close to unity. The electroosmotic properties were also discussed in terms of the conductance matrix.
The Phase Transition of 1,4-Dialkyl-1,4-diazoniabicyclo[2.2.2]octane Dibromides, Cn–DABCO–Cn+2–Br
Authors: Imamura Kengo , Shimizu Jun , Nogami Takashi
Published: July 2006

The phase transition of 1,4-dialkyl-1,4-diazoniabicyclo[2.2.2]octane dibromide (diquaternary salt) in which the difference in the carbon numbers of the two alkyl groups is two, was studied by means of differential scanning calorimetry, infrared absorption spectroscopy, and a study of the bromide-anion conductivities. DSC measurements revealed the existence of the metastable phase. The conversion rate from the metastable phase to the stable phase was too slow to be followed. The phase transition could be explained by the free energy-temperature relation. The temperature-dependence of the infrared absorption spectra showed that the band progressions due to two different alkyl chains disappeared at the transition temperature. This shows that the trans-zigzag conformation in the low-temperature phase is destroyed by the conformational change of the alkyl chain at the transition temperature. The free energy-temperature relation was also confirmed by the IR spectra. Discontinuous increases in the bromide-anion conductivities were observed at the transition temperatures. The conductivity jump was explained by the voids caused by the conformational change in the alkyl chain.
The Crystal and Molecular Structure of Diphenyl-2-pyridylmethyl Methacrylate
Authors: Kageyama Hiroyuki , Miki Kunio , Kasai Nobutami , Mohri Haruhiko , Okamoto Yoshio , Hatada Koichi
Published: July 2006

The molecular structure of diphenyl-2-pyridylmethyl methacrylate has been determined by means of X-ray diffraction. Crystals are monoclinic, space group P21⁄n, a=10.334(2), b=22.093(3), c=8.415(1) Å, β=110.92(2)°, and Z=4. The structure was established by the direct method, and refined by the block-diagonal least-squares procedure to R=0.052 (Rw=0.064) for 1702 observed reflections. The molecule has an antiperiplanar-synperiplanar conformation. One of the two phenyl groups attached to the C(5) atom is trans, and the other phenyl and 2-pyridyl groups are gauche to the C(1).
Azide-, Thiocyanate- or Cyanate-Bridged Di- and Trinuclear Copper(II) Complexes with N,N,N′,N′-Tetramethylethylenediamine, N,N-Diethylethylenediamine, 2,2′-Bipyridyl or 1,10-Phenanthroline
Authors: Nakao Yasuo , Nakamura Hideo , Mori Wasuke , Sakurai Takeshi , Suzuki Shinnichiro , Nakahara Akitsugu
Published: July 2006

A series of di- and trinuclear copper(II) complexes containing N,N,N′,N′-tetramethylethylenediamine(tmen), N,N-diethylethylenediamine(deen), 2,2′-bipyridyl(bpy) or 1,10-phenanthroline(phen) and azide, thiocyanate or cyanate ions have been prepared and characterized by their magnetic susceptibilities, infrared, electronic, and ESR spectra, and electric conductances. Magnetic susceptibility data for the dimeric complex [Cu2(tmen)2(N3)2] (ClO4)2 shows the presence of a ferromagnetic interaction (Weiss constant θ=+30 K) above 150 K, whereas the two copper(II) ions are apparently non-coupled below 150 K. On the other hand, the dimeric complex [Cu2(bpy)2(N3)2] (ClO4)2 shows the presence of a large antiferromagnetic exchange interaction (μeff<0.6 B.M. at room temperature). The complex [Cu3(tmen)3(NCS)3](ClO4)3·1.5H2O is estimated to have the trimeric structure; the temperature-dependence of the magnetic susceptibility for this compound indicates the existence of an antiferromagnetic exchange interaction with a J value of −175 cm−1.
Binuclear Metal Complexes. 58. Synthesis and Properties of Mixed-Valence Diiron(III,IV) Complexes of Salen Analogs with Pendant Thioether Group
Authors: Okawa Hisashi , Horiuchi Kaoru , Kanda Wakako , Oshio Hiroki , Kida Sigeo
Published: July 2006

Iron complexes of the composition [Fe2(L)2O]PF6 have been obtained with N,N′-disalicylidene-2-methyl-4-(1-methylethylthio)-1,2-butanediamine (H2L1) and N,N′-disalicylidene-2-methyl-4-ethylthio-1,2-butanediamine (H2L2). They were characterized as mixed-valence diiron(III,IV) complexes composed of high-spin iron(III) and low-spin iron(IV). Cryomagnetic measurements demonstrated the operation of an antiferromangetic spin-exchange interaction (J=−12.3–−13.9 cm−1) between the FeIII and FeIV ions. ESR signals at liquid nitrogen temperature (g=4.03 and 2.00) were reasonably attributed to the ground spin state (ST=3⁄2) in the spin-coupled dimer. In the Mössbauer spectra two quadrupole splitting doublets due to iron(III) and iron(IV) were observed. The complexes were discussed in comparison with mixed-valence complexes of N,N′-disalicylideneethylenediamine (H2salen), [Fe2(salen)2O]X, composed of high-spin iron(III) and high-spin iron(IV).
X-Ray and Neutron-Diffraction Study of a Stereoselectively Deuterated Benzyl t-Butyl Sulfoxide. A Revised Configuration Assignment for the Chiral Carbon Atom Due to Isotopic Substitution
Authors: Iitaka Yoichi , Itai Akiko , Tomioka Nobuo , Kodama Yoshio , Ichikawa Kazuo , Nishihata Ken , Nishio Motohiro , Izumi Masashi , Doi Kenji
Published: July 2006

X-Ray analysis of a stereoselectively monodeuterated benzyl t-butyl sulfoxide, PhCHDSO–tBu, revealed that the t-butyl and phenyl groups are oriented anti to each other in this molecule. Integrated intensities for ten reflections were measured on a two-circle neutron diffractometer and the relative intensity distribution was compared with the calculated neutron structure factors, assuming the atomic parameters obtained by the X-ray analysis. It is concluded that the benzylic hydrogen which is flanked by S–O and t-Bu was replaced by deuterium. The results require that the earlier assignment for the relative configuration of PhCHDSO–tBu, should be revised; an important conclusion in view of current discussions of sulfur stereochemistry.
Regioselectivity in the Catalytic Hydrogenolysis of 1-Amino-1-cyclopropanecarboxylic Acid and Its Methyl Ester
Authors: Isogai Koji , Sakai Jun-ichi , Yamauchi Keiji , Watanabe Katsuya
Published: July 2006

The title compounds were hydrogenolyzed over Pd–C. The ring-bond cleavage in the hydrogenolysis of the acid in water or methanol occurred at both the C1–C2 bond and the C2–C3 bond in nearly equal proportion, whereas the C1–C2 bond was cleaved mainly in the presence of ammonia and the C2–C3 bond was cleaved mainly in acetic acid. Selective hydrogenolysis of the C1–C2 bond of ester occurred in hexane or methanol, whereas the C2–C3 bond was hydrogenolyzed mainly in acetic acid. The role of the amino group is discussed.
Retentive Solvolysis. 13. The Number and the Stability of Carbocation Intermediate in the SN1 Phenolysis. Salt Effect on Retentive Phenolyses of Optically Active 2,2-Dimethyl-1-(p-substituted phenyl)propyl p-Nitrobenzoates
Authors: Kinoshita Tomomi , Ikai Keizo , Kashimura Tugunori , Fujiwara Masataka , Okamoto Kunio
Published: July 2006

The salt effect of (n-Bu)4NClO4 and NaOPh on the polarimetric and titrimetric rate constants (kp and kt, respectively) has been examined for the SN1 solvolyses of optically active 2,2-dimethyl-1-(p-methoxyphenyl)propyl (1) and 2,2-dimethyl-1-phenylpropyl p-nitrobenzoates (2) in pure phenol solvent. Four patterns, A, B, C, and D of the kp–kt profile against the added salt concentration have been observed for the phenolyses of 1, 2, and 2,2-dimethyl-1-(p-nitrophenyl)propyl p-nitrobenzoate (3). The patterns can specify the number of the sequential ion-pair intermediates (i.e., one or two), the product-forming stage (i.e., the 1st or the 2nd intermediate), and the species of reactant at the product-forming step (i.e., solvent phenol molecule, the phenoxide, or the perchlorate). The feature of the pattern of the kp–kt profile is predominantly controlled by two factors, (i) the stability of the carbocation intermediate derived from the substrates 1–3 and (ii) the nucleophilicity of the added salt. The patterns of salt effect on the product distribution (% of ROPh, o- and p-RC6H4OH) are also compatible with such rationalization of the four patterns.