bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the Social Supportive Role of Third Places in Consumers' Lives
Authors: Rosenbaum Mark S.
Published: July 2006

Using grounded theory methodology, a framework that illustrates how and why third places—that is, places such as diners, coffee shops, and taverns—become meaningful in consumers'lives is offered. The framework suggests that some consumers patronize third places to satisfy not only their consumption needs but also their needs for companionship and emotional support. These supportive needs are prevalent in older-aged consumers, who often experience events that diminish relationships. Therefore, these consumers may turn to their “commercial friendships” in third places for support. On the basis of the consumer needs that a third place satisfies, consumers identify a third place as place-as-practical, place-as-gathering, or place-as-home. The framework is verified with the Social Support Questionnaire for Transactions instrument. The data reveal that as the frequency to which consumers obtain companionship and emotional support from their commercial friendships increases, so too does their loyalty.
Phosphodiesterase 4 inhibition of β2-integrin adhesion caused by leukotriene B4and TNF-α in human neutrophils
Authors: Meliton A. Y. , Muñoz N. M. , Lambertino A. , Boetticher E. , Learoyd J. , Zhu X. , Leff A. R.
Published: June 2006

Phosphodiesterase (PDE)4 inhibition attenuates neutrophilic inflammation in chronic obstructive pulmonary disease. The objective of the present study was to examine the efficacy and mechanism by which PDE4 inhibition blocks adhesion of β2-integrin to an endothelial counterligand.

Neutrophils (polymorphonuclear leukocytes (PMNs)) were isolated from humans receiving no medication. Adhesion was analysed by myeloperoxidase activity. The effects of cilomilast±salmeterol on the following were determined: 1) surface CD11b expression; 2) adhesion; 3) intracellular cyclic adenosine monophosphate (cAMP) concentration; and 4) extracellular signal-regulated kinase (ERK)-1/2-mediated group IVA-phospholipase A2(gIVA-PLA2) phosphorylation caused by leukotriene (LT)B4or tumour necrosis factor (TNF)-α activation.

Either cilomilast or rolipram±salmeterol caused concentration-related blockade of LTB4-induced adhesion to counterligand, but had no effect on TNF-α-activated PMNs. A comparable increase in intracellular cAMP concentration for PMNs activated with LTB4and TNF-α was caused by 1 μM cilomilast and 0.1 μM salmeterol. Upregulation of surface CD11b expression and ERK-1/2 phosphorylation were blocked by cilomilast or rolipram±salmeterol for PMNs activated by LTB4, but not for cells stimulated by TNF-α. Cilomilast±salmeterol also blocked gIVA-PLA2phosphorylation caused by LTB4but not TNF-α.

In conclusion, the current study demonstrates that both leukotriene B4and tumour necrosis factor-α upregulate cyclic adenosine monophosphate. However, cyclic adenosine monophosphate does not block β2-integrin adhesion caused by tumour necrosis factor-α. It was concluded that tumour necrosis factor-α prevents inhibition of extracellular signal-regulated kinase-1/2-mediated group IVA-phospholipase A2activation, which is essential for β2-integrin adhesion in polymorphonuclear leukocytes.
Clinical evaluation of a screen pneumotachograph as an in-line filter
Authors: Normand H. , Normand F. , Le Coutour X. , Metges M-A. , Mouadil A.
Published: June 2006

The American Thoracic Society/European Respiratory Society Task Force underlined that the use of in-line filters during respiratory function tests “is an area of controversy”. The aim of the present study was to measure the contamination occurring during forced expiration downstream from a screen pneumotachograph (SP) with and without an in-line filter (Pall PF30S). A total of 40 healthy subjects performed eight consecutive maximal expiratory manoeuvres into four sterile apparatuses (A1: no filter, no SP; A2: filter-only; A3: SP-only; A4: filter and SP) in random order. A blood agar plate was fixed downstream from the apparatus. Colony-forming units (CFUs) were counted after 24 h incubation at 37°C. Of the 40 plates obtained with each apparatus, 13 were sterile with A1 (range 0–679 CFUs), 25 with A2 (0–49 CFUs), 30 with A3 (0–35 CFUs) and 39 with A4 (one CFU in the only positive plate). A1versusA2 and also A3versusA4 gave different values for the CFU number, but A2 and A3 showed similar contamination levels.

The authors conclude that: 1) the in-line filter does not perform better than a screen pneumotachograph; 2) it does not eliminate the need to decontaminate the pneumotachograph; and 3) equipment placed downstream from an in-line filter and a screen pneumotachograph is almost protected from contamination.
Prehospital Standardization of Medical Airway Management: Incidence and Risk Factors of Difficult Airway
Authors: Combes Xavier , Jabre Patricia , Jbeili Chadi , Leroux Bertrand , Bastuji‐Garin Sylvie , Margenet Alain , Adnet Fréderic , Dhonneur Gilles
Published: June 2006

Objectives:
The rate of difficult intubation in prehospital emergency medicine varies greatly among studies already published and depends on several factors. The authors' objective was to determine the rate of difficult intubations and to determine factors associated with prehospital difficult airways when a standard protocol for sedation and intubation was applied.

Methods:
This 30‐month clinical, observational, prospective study was performed in a suburb of Paris, France (Val de Marne, population 1,300,000) by a prehospital emergency medical unit. Airway management for patients who needed tracheal intubation was standardized. The pharmacological procedure recommended rapid sequence intubation for patients with spontaneous cardiac activity. In cases of difficult, laryngoscopy‐assisted intubation, a predefined algorithm was proposed. The Intubation Difficulty Score (IDS) was calculated for all patients requiring tracheal intubation, and factors associated with difficult intubation, defined by IDS of >5, were identified by using multivariate statistical analysis.

Results:
During the study period, 1,442 patients were included; 640 (44%) were in cardiorespiratory arrest, and 802 had a spontaneous cardiac activity. Deviation from the pharmacological and airway management procedures occurred in 1% of cases. When the predefined difficult airway management algorithm was followed, failure to intubate was encountered twice (0.1%). One hundred six (7.4%) patients had an IDS of >5, and 60 (4.1%) required first (n= 56) then second (n= 4) alternative techniques for tracheal intubation. Semirigid leaders allowed tracheal access in 93% of difficult‐intubation patients. One patient required a prehospital cricothyroidotomy. Factors associated with difficult intubation were the following: a history of ear, nose, or throat neoplasia or surgery; obesity; facial trauma; the operator's status; and the operator's position.

Conclusions:
If prehospital medical airway management is standardized and performed by trained operators, failure to intubate is rare (0.1%), and the incidence of difficult tracheal intubation is 7.4%, independent of cardiorespiratory status.
Kinetic Studies of the Oxygen Exchange of Chromate and Arsenate Ions with Water. Catalysis by Tellurate and Tellurite Ions
Authors: Okumura Akiko , Suda Atsuko , Saruta Atsuko , Miki Miyako
Published: June 2006

The oxygen exchange reaction of the chromate ions with water is catalyzed by the tellurate and tellurite ions. The catalytic reaction rate (RC), which is defined as the increase in the rate of the chromate-oxygen exchange upon the addition of Te(VI) or Te(IV), was studied by an 18O tracer method. The catalytic process has been interpreted in terms of the rapid reversible condensation of the Cr(VI) with Te(VI) or Te(IV) species to form hetero-poly anions. As exemplified for the Cr(VI)–Te(VI) reaction system, the rate law is given as the sum of kinetic terms: RC = ∑kij[Cr(VI)]i × [Te(VI)]j where [Cr(VI)]i and [Te(VI)]j denote the concentration of the various ionic species of the chromate and tellurate ions, respectively, and kij is the rate constant of the elementary reaction between (Cr(VI))i and (Te(VI))j. The catalytic rates were analyzed according to the rate law in order to obtain the rate constants kij. The catalytic reaction system As(V)–Te(IV) was also studied. The values of kij obtained for various catalytic systems were compared with each other.
Resolution Method of Two Sets of Binding Sites for the Cationic Surfactant–Urease Interaction
Authors: Saboury Ali Akbar , Borbar Abdoul Khalegh , Moosavi-Movahedi Ali Akbar
Published: June 2006

The binding of a homologous series of cationic surfactants with jack-bean urease has been studied by equilibrium dialysis at pH = 10 and 27 °C. The unusual concavity of a Scatchard plot has been interpreted by using the binding capacity concept. The relation between the binding capacity and the criterion of cooperativity (Hill coefficient) was obtained, and in the base of this relation a new method has been introduced for the resolution and characterization of two sets of binding sites in these systems, which is supported by microcalorimetric and spectroscopic data.
Photocatalyzed Production of Hydrogen and Iodine from Aqueous Solutions of Iodide Using Platinum-Loaded TiO2 Powder
Authors: Ohno Teruhisa , Saito Susumu , Fujihara Kan , Matsumura Michio
Published: June 2006

Hydrogen evolution and oxidation of iodide on photoirradiated Pt-loaded TiO2 powder were studied in the deaerated solutions containing iodide ions. These photocatalytic reactions have been considered to be difficult because the reaction is endothermic and reversible. However, we found that under some experimental conditions the reactions proceeded until the concentration of I3− ions reached a limiting level. The initial rate of the reactions and the limiting concentration of I3− ions in solution were enhanced as the pH of the solution decreased. In order to elucidate the pH dependence, the anodic current due to the oxidation of iodide ions on TiO2 film electrodes and the adsorptivity of iodide ions on TiO2 powder were measured. The results showed that the enhanced reactivity at low pH is due to the increased adsorptivity of iodide ions on TiO2. It was also found that the electric contact between platinum and TiO2 is important to make the reactions go forward.
Theory of Thermo- and Photo-Chemical Reactivity and Its Applications
Authors: Aono Shigeyuki
Published: June 2006

A theory of the chemical reactivity for thermo- and photo-chemical reactions is formulated in terms of the Green’s function and applied to recent observations: the photo-magnetization of a molecular crystal obtained by reduction from 2,2′-biindenyl observed by Tanaka et al., and the internal rotation of the methyl group in toluene and o-, m-, and p-fluorotoluenes observed by Ito et al.
β–α Photoisomerization of Cobaloxime Complexes in the Solid State. 5. Reaction Rate Reduced by a Hydrogen Bond
Authors: Amano Hiroki , Sekine Akiko , Ohashi Yuji , Hagiwara Mieko , Sato Junko , Arai Yoshifusa , Ohgo Yoshiaki
Published: June 2006

The crystal structures of three cobaloxime complexes with different axial base ligands have been analyzed by X-ray analysis at room temperature. I: (2-Cyanoethyl)bis(dimethylglyoximato)((S)-phenylalaninol)cobalt(III); the crystal is orthorhombic, the space group being P212121, Z = 4 with a = 9.416(3), b = 27.184(3), c = 9.184(3) Å. II: (2-Cyanoethyl)bis(dimethylglyoximato)((S)-phenyl-alanine methyl ester)cobalt(III); the crystal is monoclinic, the space group being P21, Z = 4 with a = 14.376(2), b = 11.988(2), c = 14.874(1) Å, and β = 101.05(1)°. III: (2-Cyanoethyl)bis(dimethylglyoximato)(methyldiphenylphosphine)cobalt(III); the crystal is monoclinic, the space group being P21/n, Z = 4 with a = 11.558(4), b = 15.542(3), c = 14.393(5) Å, and β = 91.02(4)°. The structures were refined by the full-matrix least-squares method to final R values of 0.041, 0.052, and 0.044 for 2340, 3287, and 4400 observed reflections, respectively. The photoisomerization rates of I, II, and III in the solid state were obtained from the changes in the IR spectra. The rate of I was insignificantly small, but the rates of II and III were calculated to be 0.1 × 10−4 and 1.9 × 10−4 s−1, respectively, assuming first-order kinetics. The 2-cyanoethyl groups in the three complex crystals take perpendicular conformations to their cobaloxime planes. The 2-cyanoethyl group of I makes a hydrogen bond with the N–H group of the neighboring molecule. The non-reactivity of I may be brought about by the hydrogen bond.
Structural and Magnetic Studies of Dimeric Copper(II) 2,2-Diphenylpropanoato and Triphenylacetato Complexes with Oxygen-Donor Ligands. The Cage Geometry of Dimeric α-Phenyl Substituted Copper(II) Carboxylates
Authors: Steward Omar W , Johnston Brian S , Chang Shih-Chi , Harada Akihiko , Ohba Shigeru , Tokii Tadashi , Kato Michinobu
Published: June 2006

The syntheses, structures, and magnetic properties of copper(II) carboxylates with bridging α-phenyl substituted carboxylato ligands and unidentate oxygen-donor ligands are reported: Cu2 (O2CCPh2Me)4(acetone)2 (1), triclinic , a = 15.441(4), b = 15.602(4), c = 12.790(2) Å, α = 106.52(2), β = 92.11(2), γ = 96.38(2)°, V = 2928(1) Å3, Z = 2, −2J = 352 cm−1; [Cu2(O2CCPh2Me)4(H2O)2]·H2O (2), triclinic , a = 13.895(2), b = 14.717(2), c = 7.318(1) Å, α = 95.67(1), β = 101.71(1), γ = 68.12(1)°, V = 1359.3(4) Å3, Z = 1, −2J = 344 cm−1; [Cu2(O2CCPh2Me)4(EtOH)2]·EtOH (3), monoclinic P21/c, a = 26.927(5), b = 9.152(3), c = 26.881(5) Å, β = 115.02(1)°, V = 6003(2) Å3, Z = 4, −2J = 347 cm−1; [Cu2(O2CCPh3)4(Ph3CCO2H)2]·CH2Cl2 (4), monoclinic P21/c, a = 18.133(8), b = 23.046(7), c = 25.013(7) Å, β = 101.01(3)°, V = 10268(5) Å3, Z = 4; [Cu2(O2CCPh3)4(H2O)2]·4H2O (5a), tetragonal , a = 18.451(6), c = 10.703(7) Å, V = 3643(3) Å3, Z = 2; [Cu2(O2CCPh3)4(H2O)2]·2H2O (5b), tetragonal , a = 18.224(2), c = 10.776(5) Å, V = 3578(1) Å3, Z = 2, −2J = 292 cm−1; and Cu2(O2CSiPh3)4(EtOH)2 (6), monoclinic C2/c, a = 21.811(3), b = 17.366(3), c = 21.221(4) Å, β = 91.19(1)°, V = 8036(2) Å3, Z = 4, −2J = 1193 cm−1. The factors which influence the cage and coordination sphere geometry in dimeric α-phenyl substituted copper(II) carboxylates are discussed based on the above structures and the reported structures with unidentate nitrogen- and oxygen-donor ligands. In 4 and 5, intramolecular steric effects between the bulky triphenylacetato ligands result in a considerable distortion of the cage geometry. The distortion of the coordination sphere geometry around copper(II) in the complexes from square pyramidal toward trigonal bipyramidal reduces the spin-exchange interaction.
Magnetic Properties of Some Triangular Trinuclear Complexes of [Ru2M(μ-CH3COO)6(μ3-O)(py)3]n+ with a Paramagnetic Ion M
Authors: Kobayashi Hanako , Uryû Norikiyo , Mogi Iwao , Miyamoto Ryo , Ohba Yasunori , Iwaizumi Masamoto , Sasaki Yoichi , Ohto Akihiro , Suwabe Masaaki , Ito Tasuku
Published: June 2006

Magnetic susceptibilities and electron paramagnetic resonances (EPRs) of coordination compounds of triangular trinuclear [Ru2M(μ-CH3COO)6(μ3-O)(py)3]n+, M = Mn(II), Fe(III), Cr(III), Ni(II), or Co(II) ions, were observed. The results were analysed by the spin vector model. Effective Bohr magneton numbers showed that the main superexchange interaction within each cluster was of the order of J/k = −300 K. This was considered to be working through μ3-O. Together with some weaker superexchange interactions through μ-CH3COO paths, fittings with the susceptibilities of the model were tried. EPR signals at temperatures of a few K were characteristic of each M ion. M = Mn(II) and M = Fe(III) were at high spin states of S = 5/2 and M = Co(II) was at a low spin state of S = 1/2. Temperature dependences of EPR signals are discussed.
Complexes of Hard Metal Ions with Amine-N-polycarboxylates as Fluoride Receptors
Authors: Yuchi Akio , Hokari Norihisa , Terao Hirohito , Wada Hiroko
Published: June 2006

The equilibria were systematically studied in the reaction of hard metal complexes (Mm+: Al3+, Zr4+, Hf4+, Th4+; HnL: amine-N-polycarboxylic acid) with fluoride. Mixed-ligand complexes were found in most systems; each metal ion shows a critical ligand having a necessary and sufficient number of donor atoms to lose the metal ion affinity for fluoride. The ML complexes of ligands containing a fewer number of donor atoms than the critical ligands have high affinities for fluoride. Among them, the zirconium(IV) complex of N-methyliminodiacetic acid is an excellent fluoride receptor; fluoride is quantitatively fixed on the complex at −log [H+] < 4.5 and is reversibly expelled at −log [H+] > 9 within a short time.
Comparative Study of the Visible Spectra of the Iron(III) Complexes of para-Substituted Tetraphenylporphyrins. Electronic Effects of Substituents and Axial Ligands
Authors: Ohya Toshie , Sato Mitsuo
Published: June 2006

The visible absorption spectra of the high-spin iron(III) complexes of the tetra-para-substituted derivatives of 5,10,15,20-tetraphenylporphyrin, Fe(p-Rtpp)X (R = OMe, H, F or Cl; X = Cl, Br or I), have been compared with each other in order to clarify the electronic effects of the phenyl substituents and axial ligands. Two charge-transfer bands shift to higher energy as the electron-withdrawing ability of the substituents increases. This is attributed to a stabilization of the porphyrin a1u(π) and a2u(π) orbitals involved in the electronic transition. These bands shift to lower energy in the order X = Cl < Br < I; the energies of these bands for I are the lowest of the three. By considering the predominantly ionic character of the bond between Fe and X, it has been proved that the iron dyz and dzx levels are lowered in this order, thereby causing a red shift. The Qv porphyrin transition shifts to lower energy in the order X = Cl < Br < I, and the Q0 transition exhibits the same trend to a less extent. These results are explained by taking into consideration two kinds of effects of axial ligands: the electron–electron repulsion in the porphyrin ring and the porphyrin skeletal vibrations.
Syntheses and Properties of Extremely Stable Di(1-azulenyl)phenylmethyl and (1-Azulenyl)diphenylmethyl Cations Having Dimethylamino Substituents on Their Phenyl Groups
Authors: Ito Shunji , Kobayashi Hiroki , Kikuchi Shigeru , Morita Noboru , Asao Toyonobu
Published: June 2006

A series of extremely stable di(1-azulenyl)phenylmethyl and (1-azulenyl)diphenylmethyl cations having dimethylamino substituents on their phenyl groups, i.e., di(1-azulenyl)[4-(dimethylamino)phenyl]methyl (5a) and (1-azulenyl)bis[4-(dimethylamino)phenyl]methyl (6a) cations and their 3-methyl-1-azulenyl (5b and 6b) and 3,6-di-t-butyl-1-azulenyl (5c and 6c) homologs, were synthesized by hydride abstraction from the corresponding hydrides. Their properties were fully characterized. As expected, the pKR+ values of these cations dramatically increased with the dimethylamino substituents on their phenyl groups. The values of 5a—c (pKR+ 13.2—13.8) and 6a—c (pKR+ 12.6—13.3) are higher by 1.4—2.7 and 8.7—9.6 pK units than those of the corresponding analogous phenyl- and diphenylmethyl cations. The redox behavior of each cation was also affected by the substituents. The oxidation of 5a—c in acetonitrile exhibited a barely separated two-step oxidation wave at potential ranges of +0.75 — +0.87 and +0.89 — +1.01 V vs. Ag/Ag+ upon cyclic voltammetry (CV), as occurs in the oxidation of tri(1-azulenyl)methyl cations. The wave is ascribed to the oxidation of the two azulene rings to generate a trication species. The oxidation of 6a—c also showed two waves at a narrow potential range at +0.74 — +0.92 V. Although the reduction of 6a—c exhibited an irreversible wave at −0.94 V, that of 5a—c showed a reversible wave at −0.87 — −0.95 V upon CV. The temperature-dependent 1H NMR spectra of 5b and 6b were also examined to clarify their stereochemistries. Stereoisomerizations due to the pyramidal dimethylamino substituents in addition to the propeller conformations of three aromatic rings were observed by low-temperature NMR studies. At higher temperature the NMR reflects the rapid isomerization of these stereoisomerisms.
Preparation of Pyrimidinophanes from Pyrimidine Bases
Authors: Itahara Toshio
Published: June 2006

Treatment of pyrimidine bases such as uracil, thymine, and 5-fluorouracil with X(CH2)nX (X = I or Br; n = 4—12) gave three types of pyrimidinophanes. When the numbers of carbon atoms of X(CH2)nX are odd numbers (n = 5, 7, 9, 11), three structures of pyrimidinophanes could be differentiated on the basis of the 13C NMR and mass spectra. Treatment of pyrimidinophanes with 1,4-naphthoquinone or maleimides in the presence of palladium(II) acetate gave the coupling products. Reaction of pyrimidinophanes with NaNO2 in the presence of palladium(II) acetate led to the nitration.
Conformational Locking by Intramolecular Hydrogen Bonding and Unlocking by Solvation Using 7-Vinylnorcaradienes
Authors: Kohmoto Shigeo , Koyano Ichiro , Kawatsuji Teruyuki , Kasimura Hideaki , Kishikawa Keiki , Yamamoto Makoto , Yamada Kazutoshi
Published: June 2006

Norcaradiene derivatives 1, 5-(1-benzyloxycarbonyl-2-methyl-1-propenyl)-3-oxatricyclo[4.4.0.01,5]deca-7,9-dien-4-one, showed a restricted rotation in the 1H NMR spectra. VT 1H NMR measurements in CDCl3 revealed the existence of two rotamers at low temperature with ΔG≠ of 11.5 (250 K), 12.1 (263 K), and 13.9 kcal mol−1 (296 K) for norcaradienes with R = H, Me, and t-Bu, where R is the para substituent of the benzyloxy group, respectively. This restricted rotation was stopped in CDCl3 at ambient temperature by introducing intramolecular hydrogen bonding via reducing of the lactone moiety to the corresponding lactols. The observed conformational locking due to the intramolecular hydrogen bonding was unlocked by solvation, resulting in the formation of three conformers in methanol-d4 and dimethyl-d6 sulfoxide. VT 1H NMR measurements of the lactol derivative in dimethyl-d6 sulfoxide showed that two of the conformers interconverted with ΔG≠ of 17.4 kcal mol−1.
Restricted Rotation Involving the Tetrahedral Carbon. LXIII. Endeavor toward Enhancing the Rotational Barrier in 9-s-Alkyltriptycenes
Authors: Oki Michinori , Fukuda Taizo , Asakura Mitsuhiro , Toyota Shinji
Published: June 2006

In order to enhance barriers to rotation about the C9-substituent bond in 9-s-alkyltritpycenes, the secondary alkyl group was modified as well as the peri-substituent. The barrier was slightly enhanced by modifying the substituents but the extent was rather limited. This limitation was attributed to the limitation of the ways of preparation of 9-s-alkyltriptycenes that should give three stable rotamers and carry substituents at peri-positions, where only 1,8-difluoro substituents could be used.
Gas-Phase Substituent Effects in Highly Electron-Deficient Systems. I. Intrinsic Stabilities of 1-Aryl-1-(trifluoromethyl)ethyl Cations
Authors: Mishima Masaaki , Inoue Hiroki , Itai Shingo , Fujio Mizue , Tsuno Yuho
Published: June 2006

The relative stabilities of 1-aryl-1-(trifluoromethyl)ethyl cations were determined by measuring the proton-transfer equilibria of 1-aryl-1-(trifluoromethyl)ethylenes or the chloride-transfer equilibria of 1-aryl-1-(trifluoromethyl)ethyl chlorides in the gas phase. The stability of 1-phenyl-1-(trifluoromethyl)ethyl cation was found to be 16 kcal mol−1 lower than that of the α-cumyl (1-phenyl-1-methylethyl) cation. The substituent effect on the stability of this cation can be correlated in terms of the Yukawa–Tsuno equation, giving an r+ of 1.41 and a ρ of −10.0 (in log K/Ko−1 unit). While the ρ value is nearly identical to that of the α-cumyl cation series, the r+ value is remarkably higher than the value of unity for the α-cumyl cation, indicating that such a highly electron-deficient carbocation system should be characterized by an extremely large r+ value compared with that of the stable α-cumyl cation. In addition, this r+ value agrees with that for the SN1 solvolysis of 1-aryl-1-(trifluoromethyl)ethyl tosylates. Such agreement of the r+ values between the gas phase and solvolysis reactions has been generally observed for the benzylic carbocation systems. It is concluded that the enhanced r+ value for the solvolysis of 1-aryl-1-(trifluoromethyl)ethyl tosylates must reflect the intrinsic resonance demand characteristic of the parent 1-phenyl-1-(trifluoromethyl)ethyl cation, itself, and that the extremely large ρ+ values given by a simple correlation with σ+ (r+ = 1) are an artifact due to an improper analysis of underestimating the resonance demand for such highly deactivated substrates.
Synthesis of Imidazole-Containing Ligands and Studies on Metal Complexes
Authors: Yamagiwa Yoshiro , Koreishi Yoshiro , Kiyozumi Satoshi , Kobayashi Masanori , Kamikawa Tadao , Tsukino Mitsuji , Goi Hironori , Yamamoto Mikiko , Munakata Megumu
Published: June 2006

1,5-Di(imidazol-1-yl)-3-[2-(imidazol-1-yl)ethyl]pentane, 1,7-di(imidazol-1-yl)-4-[3-(imidazol-1-yl)propyl]heptane, N,N′,N″-tris[2-(imidazol-4-yl)ethyl]benzene-1,3,5-tricarboxamide, and 1,3,5-tris[3-(imidazol-1-yl)propyl]benzene (TIPB) have been synthesized for a study of the formation and characteristics of zinc complexes. TIPB forms a crystalline zinc complex, not a tetrahedral complex but an octahedral complex. Other ligands form either microcrystalline complexes or polymer complexes with zinc.
Photoinduced Electron-Transfer Reaction of (Phenylazo)triphenylmethane (PAT). Behavior of Generated Trityl Cation
Authors: Miyagawa Nobukazu , Karatsu Takashi , Futami Yasuo , Kunihiro Takeshi , Kiyota Atsushi , Kitamura Akihide
Published: June 2006

The decomposition mechanism of photoinduced electron transfer (PET) between electron deficient sensitizers and (phenylazo)triphenylmethane (PAT) was investigated. In 9,10-dicyanoanthracene (DCA) sensitized reaction, benzene, triphenylmethane, 3,3,3-triphenylpropionitrile, and [4-(diphenylmethyl)phenyl]acetonitrile were obtained, and the product distribution was the same as for the direct photolysis and the thermolysis. In the case of 2,4,6-triphenylpyrylium tetrafluoroborate (TPP+) sensitization, the product distribution was drastically changed and 9-phenylfluorene was found to be one of the main products. The results of the irradiation wavelength effects indicate that 9-phenylfluorene is produced by the photoreaction of a trityl cation which is generated by the decomposition of a radical cation of PAT. The results of the experiments of laser flash photolysis suggest that the rate of back electron transfer between a radical anion of the sensitizer and a trityl cation plays an important role in these reactions.
Syntheses of 3,4-Disubstituted 2-Tosylpyrroles and 5-Tosyl-1,5-dihydro-2H-pyrrol-2-ones Starting from Ethyl 3,4-Disubstituted 2-Pyrrolecarboxylates
Authors: Murata Yasue , Kinoshita Hideki , Inomata Katsuhiko
Published: June 2006

The syntheses of 3,4-disubstituted 2-tosylpyrroles and 5-tosyl-1,5-dihydro-2H-pyrrol-2-ones were accomplished via 3,4-disubstituted 2-iodo-5-tosylpyrroles starting from ethyl 3,4-disubstituted 2-pyrrolecarboxylates.
Reactivities of Stable Rotamers. XXXVIII. Reaction of Chlorine with 1-(9-Fluorenyl)-2-(1-methylethenyl)naphthalene Rotamers: Outstanding Solvent Effects on Product Distribution and Ritter Type Reactions in Acetonitrile
Authors: Oki Michinori , Hirose Takanori , Aki Michihiko , Morita Nobuhiro , Nose Emiko , Kataoka Yasukazu , Ono Masaru , Toyota Shinji
Published: June 2006

Reactions of the olefinic moiety of the title compounds with chlorine were done as carbon tetrachloride, nitromethane, and acetonitrile solutions. The ap-isomer afforded a mixture of the corresponding addition product and olefins that are derived by deprotonation of the intervening chloro-carbocation. The product distribution was strongly affected by the solvents, although chlorinated olefins are the main products in carbon tetrachloride. The sp-isomer yielded the chloro-olefins that are rotationally isomeric with these compounds in carbon tetrachloride. No cyclized compound, which is expected if the attack of the intermediate cation on a benzene ring closely located to it takes place, was detected under these conditions. By contrast, the reaction in nitromethane resulted in formation of the cyclized compound as a major product from the sp isomer. In acetonitrile, the reaction afforded the cyclized compound in a fair yield from the sp, but that of the ap isomer gave products that were derived by the Ritter type reactions, in addition to those observed in other solvents. The results are attributed to the stability of the intervening cations in these solvents. In the Ritter type reaction, the first evidence that deprotonation from the intervening acetonitrilium ion to produce a ketene imine was obtained. The bromine addition to the olefinic bond in the sp-isomer of the title compound revealed that the solvent seriously affects the yields of the cyclic compound as well as the ratios of two bromo-olefins.
Effect of Acid Deposition on Urban Dew Chemistry in Yokohama, Japan
Authors: Okochi Hiroshi , Kajimoto Takuya , Arai Yukiko , Igawa Manabu
Published: June 2006

Dews or frosts formed on artificial collectors were collected during the early morning in Yokohama in 1993 and 1994 and analyzed for weak acids as well as major inorganic ions. In 1993 (n = 21) the dew pH ranged from 3.23 to 7.12 and averaged 4.60; in 1994 (n = 56) it ranged from 4.11 to 7.74 and averaged 5.41. Based on the average, NH4+ and Ca2+ were major cations (423 and 178 μequiv L−1 for NH4+ and Ca2+ in 1993, respectively, and 454 and 274 μequiv L−1 in 1994, respectively) and SO42− was the dominant anion (344 μequiv L−1 in 1993 and 271 μequiv L−1 in 1994) in dew water. The dew chemistry was characterized by relatively high concentrations of weak acid anions, particularly hydrogensulfite ion (HSO3−). Dew water sometimes had very high acidity (the minimum pH was 3.23 during the period of this research), which might have been due to the aqueous oxidation of S(IV). From a resistance model calculation, the S(IV) concentration in dew water was suggested to be influenced by the dissolution of HCHO from the atmosphere and the subsequent formation of HMSA.
Effect of Pressure on Subtilisin Catalysis: Hydrolysis and Peptide Synthesis
Authors: Kunugi Shigeru , Kobayashi Ichizo , Takano Kazuya , Murakami Yukiko
Published: June 2006

The effects of high pressure on the subtilisin (Carlsberg) catalyzed hydrolysis and aminolysis reactions were investigated.

The pH dependence of the apparent second-order rate constant (kcat/Km(app)) for N-glutaryl–Ala–Ala–Pro–Leu–pNA showed a slightly lowered profile due to increasing pressure. The pressure dependence (up to 150 MPa) of kcat/Km(app) for this substrate or N-benzyloxycarbonyl–Gly–Gly–Leu–pNA at a constant pH (8.5) showed slightly positive activation volumes: + 2—3 ml mol−1.

The substrate concentration dependence of the hydrolytic rate for N-succinyl–Ala–Ala–Pro–Phe–pNA showed increased slope and Y-intercept on an Eadie plot at 150 MPa; the reaction volume for the 1/Km was positive and the activation volume for kcat was estimated to be negative. Pressure affected the two parameters in the opposite directions, and as a result, the effect on kcat/Km(app) became rather small.

Pressure promoted the subtilisin-catalyzed transacylation reaction between Fua–Phe–OMe and GlyNH2, but the fraction of the peptide formation (fa) decreased slightly under high pressure. Pressure seemed to accelerate the hydrolytic process much more, especially the nucleophile-assisted hydrolysis of the acyl-enzyme, than the acyl-transfer to the nucleophile.
Phase Behavior of Bipolar Fatty Acid Monolayers
Authors: Huda Masud S , Fujio Katsuhiko , Uzu Yuhei
Published: June 2006

The phase behaviors of the monohydroxy- and dihydroxy-substituted fatty acids at an air–water interface were investigated in the presence of different substrates. All of the hydroxylated fatty acids studied, except for 2-hydroxyoctadecanoic acid (2-HOA) and 9,10-dihydroxyoctadecanoic acid (9,10-DHOA), showed an intermediate region (“plateau”) for a transition from a liquid-expanded state (LE) to a liquid-condensed state (LC) in the π–A isotherms, regardless of the substrate composition. In contrast, 9,10-DHOA exhibited a pressure plateau region on only 3 M NaCl. In order to assess the effect of adding an extra polar group (i.e., a hydroxy group) for a 9,10-DHOA monolayer compared to a 9-hydroxyoctadecanoic acid (9-HOA) monolayer, the monolayer-substrate interactions were considered based on the thermodynamic parameters for the LE/LC phase transition, using a two-dimensional Clausius–Clapeyron equation. This can be explained by assuming that a greater energy was generated for breaking of hydrogen bonds between the two hydroxy groups of 9,10-DHOA and water. In this regard, the dynamic properties of the monolayer for these acids were examined using the surface pressure relaxation method as well as an equilibrium spreading pressure (ESP) measurement.
MO-Theoretical Description of Electronic Structures of Tricentric Bisdesmiphiles in the Ground and Excited States
Authors: Yoshioka Yasunori , Yamaki Daisuke , Maruta Goro , Tsunesada Tsunaki , Takada Kazuhiro , Noro Takeshi , Yamaguchi Kizashi
Published: June 2006

A systematic MO-theoretical description of electronic structures of tricentric bisdesmiphiles in the ground state is presented in response to contradictory arguments on the biradical character of the species by Huisgen, Firestone, and others. The approximately spin-projected but size-consistent (AP) UHF and UMP methods remedy artifact arising from the spin contamination effect involved in the singlet UHF and UMP wavefunctions, giving reasonable a different-orbitals-for-different-spins (DODS) MO description for oxygenated dipoles such as O3 and CH2OO and 1,3-biradicals without octet stabilization such as OCH2O and CH2CH2CH2. The RHF method provides well-accepted MO description for diszonimum and nitrilium betaines having little biradical character, and the RMP method works well even for species with weak biradical character. They are successfully applied to calculating relative energies between nonradical ring- and biradical open-forms of tricentric species, singlet–triplet energy gaps of tricentric biradicals, and high- and low-spin energy gaps of polyradicals constructed of 1,3-biradical units. Reliability of the projected UHF and UMP scheme for biradical species was confirmed by the complete active space (CAS) configuration interaction (CI) by the use of UHF natural orbitals (UNO). The UNO CASCI calculations are also carried out both for the ground and excited of 1,3-biradicals. The energy gradient technique based on UNO CASSCF is applied to the full geometry optimizations of tricentric systems, followed by the UNO CASSCF MP2 calculations for dynamical correlation corrections. On the other hand, the UNO MR SDCI method by the use of the UNO CASCI reference gives a well-balanced MO-theoretical description of the ground and excited states. Comparisons of different definitions of biradical character are given in relation to theoretical explanations of 1,3-dipoles and 1,3-dipolar reactions. It is shown that the present MO-theoretical description based on both delocalized and localized natural orbitals is wholly compatible with experimental data obtained by Huisgen and others.
Several Factors Affecting the Detection Sensitivity of the Reaction Heat-Induced Optical Beam Deflection Method
Authors: Wu Xing-Zheng , Kitatani Hideki , Uchiyama Katsumi , Hobo Toshiyuki
Published: June 2006

In order to improve the detection sensitivity of the reaction heat-induced optical beam deflection method, the experimental factors that affect the detection sensitivity were investigated in detail. Firstly, different types of deflection detectors were compared. The experimental results showed that the bi-cell photodiode detector is most sensitive to the deflection signal. Secondly, the effect of the size of the reaction cell on the detection sensitivity was investigated. A small reaction cell gave a stable baseline and small noise in flow injection experiments, and thus gave a high detection sensitivity. Thirdly, the effects of the optical arrangements on the detection sensitivity were investigated. Focusing the probe beam close to the gold film/CCl4 interface enhanced the detection sensitivity. Also, refocusing the deflected probe beam improved the sensitivity. Under the selected experimental conditions, the detection of the neutralization reaction between HCl and NaOH at sub-nanomol level became possible. Further improvements are also discussed.
Through-Bond and Through-Space Interactions of Organic Radicals Coupled by m-Phenylene
Authors: Yoshizawa Kazunari , Kuga Takako , Sato Tohru , Hatanaka Masashi , Tanaka Kazuyoshi , Yamabe Tokio
Published: June 2006

Through-bond and through-space magnetic interactions in tricarbene and its related triradicals coupled through m-phenylene units are discussed with a semiempirical molecular orbital method including configuration interactions (PM3-CI method). The high-spin (HS) and low-spin (LS) states have quite similar geometries, but the methylene bridging angle is larger in the HS states. The HS states of these lie well below the corresponding LS states, except for one which contains nitroxide and aminiumyl radicals. Instability of the HS state of the heteroatomic system is a consequence of significant mixing between NBMOs and benzene e1g-type orbitals, which can be explained in terms of simple perturbation theory. The energy difference between the HS and LS states is not explicitly influenced by the conformation of the molecules examined. This shows that such conformations have little effect on the magnetic properties in possible polymer ferromagnets which contain m-phenylene coupling units, as far as the second nearest neighbor interaction.
Viscosity-Dependent Decay Dynamics of the S2 State of Cyanine Dyes with 3, 5, and 7 Methine Units by Picosecond Fluorescence Lifetime Measurements
Authors: Kasatani Kazuo , Sato Hiroyasu
Published: June 2006

The lifetimes of the short-wavelength (SW) fluorescence of some cyanine dyes with 3, 5, and 7 methine units were measured using a synchronously pumped picosecond dye laser in conjunction with the time-correlated single-photon counting method. The lifetimes were longest for dyes with 5 methine units, and decreased in the order of 5, 7, and 3 methine units. The lifetimes were highly dependent on the solvent viscosity. The dependences were compared with those of the fluorescence quantum yields previously reported by the authors in order to determine the relative importance of direct internal conversion (viscosity-independent) relaxation channel and that of the crossing-over to the photoisomer potential energy curve (viscosity-dependent channel). It was determined that origin of the SW fluorescence was the second excited singlet state by semiempirical molecular orbital calculations. The absolute SW fluorescence quantum yield of one of the cyanine dyes, DODC, was found to be less than 0.002 in ethanol. The relaxation rates of these cyanine dyes in the first and second excited singlet states were compared.
Speciation of Trace Metals in Pond Water as Studied by Liquid Chromatography/Inductively Coupled Plasma Mass Spectorometry
Authors: Itoh Akihide , Kimata Chisen , Miwa Hajime , Sawatari Hideyuki , Haraguchi Hiroki
Published: June 2006

An on-line separation-detection system, liquid chromatography coupled with inductively coupled plasma mass spectrometry (ICP-MS), has been developed and applied to the study on speciation of trace metals in pond water. First, the total concentrations of dissolved metal ions in pond water were determined by ICP-MS after chelating resin preconcentration. Then, pond water was preconcentrated by ultrafiltration using a filter with a molecular weight permeation limit of 10000, providing size exclusion chromatography. Large organic molecules which had combined with trace metals in the preconcentrated samples were separated with a gel filtration column and detected by UV absorption and ICP-MS, sequentially. In consequence, large organic molecules with the molecular weight of ≥300000 and 10000—50000 could be observed. A large number of trace metals (41 elements) were found in those organic molecules. Furthermore, the percentages of metal ions in the forms of large organic molecule–metal complexes were estimated from their concentrations as determined by the flow injection method.
Silver Extraction for Pollution Control of Photographic Fixing Solution with Tetramethylthiuram Disulfide
Authors: Mendoza Concepcion S , Kamata Satsuo
Published: June 2006

Silver recovery from photographic fixing solutions can be performed by solvent extraction with thiuram disulfides. Tetramethylthiuram disulfide (TMTDS) was selected for further studies because it had the highest distribution ratio among the three extractants. Its selectivity for silver extraction from a thiosulfate medium and from an analytical photographic fixing solution were evaluated. A 1 : 1 silver(I)–TMTDS complex is formed. For a one-stage and one-hour silver(I) extraction process, a 96% recovery was obtained from an analytical fixing solution containing 1 g dm−3 silver(I), starting with a 0.02 M (1 M = mol dm−3) TMTDS solution. The possible extraction mechanism involves the reduction of TMTDS in the presence of thiosulfate ions, followed by chelation of the silver(I) with the reduced TMTDS. Effective stripping can be performed by using 3 M hydrochloric acid. By dilution of the fixing solution with water (1 : 1), and the use of 0.1 M TMTDS, recycling of the organic phase between the extraction and stripping stages for silver extraction can be achieved in a few times. The results for the analytical solutions were further shown to be applicable to a black and white photographic industrial solution.
Study on Efficient Synthetic Routes for 7-Fluoroprostaglandin F2α and 7-Fluoro-17,20-dimethyl-2,4-methyleneprostacyclin
Authors: Matsumura Yasushi , Shimada Toyomichi , Wang Shu-Zhong , Asai Tomoyuki , Morizawa Yoshitomi , Yasuda Arata
Published: June 2006

New and facile syntheses of 7-fluoroprostaglandin F2α  1 and chemically stable 7-fluoro-17,20-dimethyl-2,4-methyleneprostacyclin 2 from commercially available methylenecyclopentanone are described. Construction of the key 7-hydroxyprostaglandin skeleton has been efficiently accomplished by the coupling of acetylenic acids with cyclopentanecarbaldehyde 4 under mild conditions.
Photo-Induced Reactions of Oxime O-Ethers Derived from 3-Acyl-1,2-dihydrocinnoline-1,2-dicarboximides
Authors: Tanaka Satoko , Seguchi Kazuyoshi , Itoh Kuniaki , Sera Akira
Published: June 2006

The irradiation of oxime O-ethers 2, derived from N-substituted 3-acyl-1,2-dihydrocinnoline-1,2-dicarboximides in benzene, afforded rearranged products 3 possessing a [1,3,5]triazino[1,2-a]indole skeleton in good yields. Upon irradiation, 7-methoxy-substituted 1,2-dihydrocinnoline-1,2-dicarboximides 2 gave a novel dimer 5 together with the rearranged triazinoindole derivatives 3 in benzene, while in nucleophiles they gave the nucleophile-incorporated dihydrotriazinoindoles 6. However, the 7-nitro-substituted one was inert under the same conditions. The dimer and dihydrotriazinoindole derivatives were thought to be formed by a nucleophilic attack of the initial photoproduct 3 and nucleophiles to 2, respectively. From these results and the observation of a remarkable solvent-dependency of the fluorescence and UV spectra of 2, it was suggested that these photoreactions should occur through a nitrogen–nitrogen bond cleavage at polar excited states followed by skeletal rearrangements.
Total Syntheses of PI-201 and Related Compounds
Authors: Murata Takeshi , Kumagai Toshihito , Ishikawa Makoto , Tadano Kin-ichi , Ogawa Seiichiro
Published: June 2006

The thermal intramolecular Diels–Alder cycloaddition of a 2 : 1 mixture of ethyl (2E,8E and Z, 10E,13R)-13-(t-butyldimethylsilyl) oxy-2,10-dimethyl-2,8,10-pentadecatrienoate provided four diastereomeric cycloadducts. Deprotection of one of the cycloadducts provided PI-201, a novel platelet aggregation inhibitor, as its natural form. Three stereoisomers of PI-201 were prepared from the other cycloadducts. The intramolecular cycloadditions of some structurally similar trienes were also investigated.
Supramolecular Stacks of Bis(imidazolyl)porphyrin through Metal Coordination
Authors: Kobuke Yoshiaki , Miyaji Hidekazu
Published: June 2006

cis- and trans-bis(1-methyl-2-imidazolyl)tetraethyltetramethylporphyrin Mg complexes were prepared. 1H NMR, absorption, and fluorescence spectra suggest that Mg has a high tendency toward dimer formation through coordination from imidazolyl to metal in a similar way to Zn, and accepts further the sixth coordination, which never occurred in Zn complexes. Propagation of the organization from a dimer to a trimer for trans-Mg complex starts at such a low concentration level as 10−5 M (1 M = 1 mol dm−3) and a 2 × 10−3 M solution organized the system to a 2.34 mer on average.
Relation between the Activity of Catalytic Antibodies and the Properties of Substrates
Authors: Kodaka Masato , Hase Anneli
Published: June 2006

The free energy of binding between catalytic antibodies and substrates is correlated with the properties of the substrates, both in the transition state (TS) and the ground state (GS). The free energy of binding was calculated from the kinetic parameters and four properties of the substrates; the solvent accessible surface area (SAS), enthalpy of hydration (ΔH), polarizability (α), and dipole moment (μ) were calculated using AM1. As a whole, TS shows a higher correlation than does GS, which is compatible with the fundamental concept of a catalytic antibody. Among these four properties, SAS gives the highest correlation coefficient (0.7616) while μ has a small correlation. Antibody-TS complexes seem to be stabilized by van der Waals force rather than a hydrophobic interaction.
Facile Optical Resolution of a Dibenzopyrazinoazepine Derivative and the Nature of Molecular Recognition of Amines by Chiral 2,3-Di-O-(arylcarbonyl)tartaric Acids
Authors: Tomori Hiroshi , Yoshihara Hisayoshi , Ogura Katsuyuki
Published: June 2006

A facile optical resolution of recemic 1,2,3,4,10,14b-hexahydrodibenzo[c,f]pyrazino[1,2-a]azepine (1) was developed using 2,3-di-O-benzoyl-d-(−)-tartaric acid ((+)-DBT) as a resolving agent. The resolution efficiency depends remarkably on the (+)-DBT : 1 ratio. When (+)-DBT and recemic 1 were mixed in methanol–water (9 : 1 v/v) in a 1 : 4 stoichiometry, a crystalline salt consisting of (+)-DBT, (R)-1, methanol, and water in a 1 : 2 : 2 : 2 ratio crystallized preferentially in a fair yield. X-Ray crystallographic analysis showed its highly ordered supramolecular structure: (+)-DBT molecules self-assemble via hydrogen bonding with the aid of water and methanol to form a puckered layer, and stacking of (R)-1 molecules constructs a column which is sandwiched in between the puckered layers. The X-ray crystallographic data reported for the salts that consist of amines and DBT were reinvestigated to reveal that most of the host frameworks derived from DBT have a layer structure similar to the above puckered one.
On the Conformation of the Substrate Binding to the Active Site during the Course of Enzymatic Decarboxylation
Authors: Kawasaki Takayasu , Horimai Emiko , Ohta Hiromichi
Published: June 2006

The activation parameters of the enzymatic decarboxylation of malonic acid derivatives catalyzed by arylmalonate decarboxylase (AMDase) were obtained by means of kinetics. In order to understand the conformation of the substrate at the transition state, the activation entropy (ΔS‡) for indane-1,1-dicarboxylic acid, a representative molecule that is conformationally restricted, was compared with those of phenylmalonic acid and ortho-chlorophenylmalonic acid, of which the aromatic ring can freely rotate. The obtained value for the former molecule was about 10 cal mol−1 K−1 smaller than those of the latter compounds, clearly indicating that a conformationally restricted substrate, such as the indane derivative, is entropically advantageous for enzymatic decarboxylation. These kinetic studies evidently disclose that the conformation of the substrate at the transition state in the course of AMDase-catalyzed decarboxylation should be synperiplanar with regard to ortho- and α-substituents.