bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Spectral Properties of Oxovanadium(IV), Nickel(II), Copper(II), and Palladium(II) Complexes of Tetraaza[14]annulenes
Authors: Sakata Kazunori , Hashimoto Mamoru , Tagami Noriyoshi , Murakami Yukito
Published: July 2006

The oxovanadium(IV), nickel(II), copper(II), and palladium(II) complexes of 5,14-dihydrodibenzo[b,i][1,4,8,1l]tetraazacyclotetradecine and 7,8,15,16,17,18-hexahydrodibenzo[b,j][1,4,8,1l]tetraazacyclotetradecine have been synthesized, and studied by electronic, vibrational, NMR, ESR, and ESCA spectroscopy. The absorption bands appearing in the energy region greater than 16800 cm−1 were attributed to π→π* transitions within a ligand molecule and metal to ligand charge-transfer transitions. The ligand-field bands were not assigned for the present complexes, because all the ligand-field bands were obscured by the π→π* and charge-transfer bands of high intensity. The metal complexes assume the square-planar configurations since no significant absorption band was detected in the region below 17000 cm−1. A strong band appearing at ca. 1620 cm−1 was assigned to the C=N stretching mode, and this band was shifted to lower frequency upon metal coordination. A V=O streching band was observed at ca. 950 cm−1 for the oxovanadium complexes. The oxovanadium, nickel, copper, and palladium complexes showed a single nitrogen Is peak by ESCA spectroscopy, whereas the metal-free ligand, 5,14-dihydrodibenzo[b,i][1,4,8,1l]tetraazacyclotetradecine, revealed double nitrogen Is peaks. ESR spectra were measured in xylene–benzene (2: 1 v/v) as well as in the corresponding ligand matrices at room temperature. Judging from g tensors, the copper complexes were confirmed to have D2h coordination symmetry with an unpaired electron in the dxy orbital. On the other hand, vanadium(IV) is in C4v coordination symmetry with an unpaired electron in the dx2−y2.
Photoreaction of D-Nor-5α-androstan-16-one Oxime, a Steroidal Cyclobutanone Oxime
Authors: Suginome Hiroshi , Uchida Tsutomu
Published: July 2006

Irradiation of D-nor-5α-androstan-16-one oxime in methanol leads to a mixture of seco-nitriles; D-nor-13,16-seco-5α-androst-13(18)-ene-16-nitrile (3), D-nor-13,16-seco-5α-androst-12-ene-16-nitrile (7), 13ξ-methoxy-D-nor-13,16-seco-5α-androstane-16-nitrile (8), and 15-hydroxy-D)-nor-15,16-seco-5α-androstane-16-nitrile (9). These result from ionic α-fissions at either of the α-bonds. Low yields of three lactams, 17-aza-5α-androstan-16-one (6), 17-aza-5α,13α-androstan-16-one (11), and 16-aza-5α-androstan-17-one (5), resulting from photo-Beckmann rearrangement, are also formed. The formation of 11 is the second proven example of a photo-Beckmann rearrangement in which a chirality of the migrating carbon center is not retained in the product lactam and an intervention of a ring-opened intermediate must be involved. It was found that direction of the α-cleavage of this excited four-membered cyclic ketone oxime was not governed only by the stability of cleaved ions, since seco-nitrile 9 resulting from α-fission to a less stable primary carbonium ion was formed together with seco-nitriles 3, 7, and 8 from a more stable tertiary carbonium ion. The Beckmann rearrangement of the mixture of syn and anti oximes with thionyl chloride afforded the two expected lactams 5 and 6 together with the products of Beckmann fission 3 and D-nor-13,16-seco-5α-androst-13(14)-ene-16-nitrile resulting from a cleavage to tertiary carbonium ion.
The Confirmation of the Configuration of Ethyl 2-Bromo-3-nitro-2-alkenoate by l3C NMR Spectroscopy
Authors: Shin Chung-gi , Yonezawa Yasuchika , Ajisaka Katsumi , Yoshimura Juji
Published: July 2006

The configuration of the ethyl 2-bromo-3-nitro-2-alkenoate formed by the elimination of hydrogen bromide from ethyl 2,3-dibromo-3-nitroalkanoate was determined to be (Z) by the examination of the 13C NMR spectra.
Retardation of the Cleavages of Nitrophenyl 1-Adamantanecarboxylates by Cyclodextrins
Authors: Komiyama Makoto , Inoue Shohei
Published: July 2006

Cleavages of p- and m-nitrophenyl 1-adamantanecarboxylates (1 and 2) were carried out in the presence of α-, β-, and γ-cyclodextrins at 16 °C. The complex formation of 1 with α-, β-, and γ-cyclodextrins decelerated its cleavage by 3.2, 28, and 13 fold, respectively, in the 99 : 1 (v/v) mixture of 0.1 mol dm−3 NaOH aqueous solution and acetonitrile. All α-, β-, and γ-cyclodextrins showed decelerations of the cleavages of 1 and 2 also in the 66 : 34 mixture of 0.1 mol dm−3 NaOH aqueous solution and acetonitrile, although the magnitudes of the rate effects were smaller. The decelerations of the cleavages of 1 and 2 by cyclodextrins were markedly in contrast with the accelerations of the cleavages of other phenyl esters by cyclodextrins previously reported, and were ascribed to the formation of the complexes, in which 1 and 2 were protected sterically and/or electrostatically by cyclodextrins.
Neighboring Group Participation in Solvolysis. X. Dissection of Ar1-5 and Ar2-6 Pathways in Trifluoroacetolysis of 4-Arylbutyl 6-Methyl-2-naphthalenesulfonates
Authors: Ando Takashi , Yamawaki Junko , Saito Yoshimasa , Takai Yoshio , Yamataka Hiroshi
Published: July 2006

Trifluoroacetolysis rates and products were determined for eleven 4-(m- and p-substituted phenyl) butyl 6-methyl-2-naphthalenesulfonates. Most substrates solvolyze predominantly or even exclusively with aryl assisted (kΔ) pathway. Dissection of kΔ into Ar1-5 and Ar2-6 components was performed by means of quantitative 13C NMR study of suitably labeled p-methyl and p-fluoro derivatives; the results were 32.4% Ar1-5 and 67.6% Ar2-6 for the former and 43.3% Ar1-5 and 56.7% Ar2-6 for the latter. For other substrates the dissection was carried out by postulating two independent linear free energy relationships (LFER) for the two pathways determined by the above four partial rates. Ar2-6 is much prefered over Ar1-5 through the series; for the unsubstituted derivative 90.6% Ar2-6 vs. 9.4% Ar1-5 was determined. A completely different approach by means of non-linear regression analysis of kΔ as a sum of two independent LFER gave fairly different and rather unsettled results, limitations of such an approach being suggested. The characteristics of remote aryl participation are discussed based on the above data.
Oxidation Studies with Peroxomonophosphoric Acid. III. A Kinetic and Mechanistic Study of Oxidation of Dialkyl Sulfides
Authors: Panigrahi Ganesh Prasad , Panda Radhasyam
Published: July 2006

The kinetics of oxidation of dialkyl sulfides by peroxomonophosphate in aqueous medium at 308 K and μ=0.4 mol dm−3 follow the rate expressions (i) −d[peroxomonophosphate]/dt={k1[H2PO5−]+k2[HPO52−]}[sulfide] in the pH region 6.8–8.7 where k1 and k2 values are 336.5 and 0.95, 69.7 and 0.254, and 27.5 and 0.126 dm3 mol−1 s−1 for dimethyl, diethyl and dipropyl sulfides, respectively, (ii) −d[peroxomonophosphate]/dt=k2[HPO52−]·[sulfide] in the pH region 8.5–12.5, where the average k2 values are 0.86, 0.247, and 0.128 dm3 mol−1 s−1 for dimethyl, diethyl, and dipropyl sulfides, respectively, and (iii) −d[peroxomonophosphate]/dt={k2[HPO52−]+k3·[PO53−]}[sulfide] in the pH region 12.5–13.7, the k2 and k3 values being 0.947 and 0.107, and 0.233 and 0.018 dm3 mol−1 s−1 for dimethyl, and diethyl sulfides, respectively. The mechanism of the reaction is in line with a nucleophilic attack of the sulfide-sulfur on the peroxo oxygen, giving rise to SN 2-type transition states which undergo oxygen-oxygen bond fission to give the corresponding sulfoxide and phosphate.
Concentration Dependence of Flow Properties of Molten Salt Systems
Authors: Islam Nurul , Ali Anwar
Published: July 2006

The concentration dependence of fluidities and conductances of molten calcium nitrate tetrahydrate–MNCS (M=Na+ or NH4+) systems was quantitatively explained by the isoenergetic and isoentropic equations essentially based on the Vogel-Tammann-Fulcher (VTF) and the Configurational Entropy Model (CEM) equations. The pre-exponential terms of the VTF and the Doolittle’s equations were found to depend linearly on the values of the corresponding parameters, i.e., T0 the zero mobility temperature and those of V0, the molar intrinsic volume at T0, respectively. The linear interdependence of the two thermodynamic parameters, T0 and V0 on each other has been demonstrated. In addition to the linear dependence of the corrected energy of activation, Ecor on V0, a physically meaningful linear dependence of Ecor on T0 has also been demonstrated.
Determination of Uranium and Thorium with Arsenazo III after Sequential Extraction from Acid-deficient Aluminium Nitrate Medium
Authors: Ramakrishna T V , Shreedhara Murthy R S
Published: July 2006

Uranium has been quantitatively extracted into IBMK from ≈2.2 mol dm−3 aluminium nitrate solution at pH 0.8–0.9. Coextracted thorium (≈10%) is returned to the aqueous phase by addition of benzene. Subsequently, thorium is extracted into IBMK in the presence of hexadecyltrimethylammonium bromide (CTAB). This separation method has been applied to the analysis of uranium and thorium content of monazite sand.
An ESR Study of N,N-Bis(arylthio)aminyls. 33S Hyperfine Splittings
Authors: Miura Yozo , Kinoshita Masayoshi
Published: July 2006

In the ESR spectra of N,N-bis(phenylthio)-, N,N-bis(phenyl-d5-thio)-, and N,N-bis(3,5-dichlorophenylthio)aminyls, 33S hyperfine splittings were detected. The spin densities in the aminyls were calculated by using the HMO calculations with and without McLachlan’s correction, and the results were compared with the values derived from the 1H, 14N, and 33S hyperfine splittings by use of the relationship a=Qρ.
Liquid Phase Peptide Synthesis by Fragment Condensation on Soluble Polymer Support. IV. Relative Reactivities of N-t-Butoxycarbonyl-(Boc)amino Acids and Boc-Oligopeptide Acids in Their Esterification with Soluble Chloromethylated Polystyrene
Authors: Narita Mitsuaki , Kusano Kazuya , Hirata Masanori , Okawara Makoto
Published: July 2006

Relative reactivities of N-t-butoxycarbonyl(Boc)amino acids (Gly, Val, Ile, Leu, Tyr, and Phe) and Boc-oligopeptide acids having various numbers of amino acid residues (n=2, 4, 5, 8, and 10) were determined by competitive esterification in reaction with chloromethylated polystyrene. Increase of peptide-chain lengths reduced reactivity of C-terminal carboxylates.
Synthesis of 1-Benzothiopyrylium Perchlorates and Related Compounds
Authors: Nakazumi Hiroyuki , Kitao Teijiro
Published: July 2006

The blue colored 1-benzothiopyrylium perchlorates were synthesized by the reduction of thiocoumarins with lithium aluminium hydride followed by the treatment with acid. A number of new thiocarbonyl derivatives of thiocoumarins and thiochromones were also synthesized, the spectral characterization of which has been described.
Reaction of Phenacyltriphenylarsonium Bromides with N-Methylaniline and N,N-Dimethylaniline
Authors: Bansal Raj Kumar , Bhagchandani Gope
Published: July 2006

Reaction of phenacyltriphenylarsonium bromide with N-methylaniline furnished 2-phenylindole predominantly together with 1-methyl-2-phenylindole. The corresponding reaction of the arsonium salt with N,N-dimethylaniline did not give any indole, instead a simple nucleophilic substituted product, α-4′-(dimethylamino)deoxybenzoin was obtained. But, the latter reaction on being carried out in presence of hydrobromic acid afforded 1-methyl-2-phenylindole by the demethylation of N,N-dimethylaniline.
Resonance Raman Spectra of Intermolecular Vibrations of Würster’s Cation Dimers
Authors: Yokoyama Kenji , Tajima Yoshitaka , Tahara Masao , Maeda Shiro
Published: July 2006

The resonance Raman spectra of some Würster’s cation dimers were measured in alcohol solution at 201 K and in glassy matrix at 77 K. The spectra of the dimer of p-phenylenediamine cation showed the resonance enhancement of the Raman line assigned to the intermolecular stretching vibration and supported the D2h symmetry for the dimer. However, for the dimer of 2,3,5,6-tetramethyl-p-phenylenediamine cation and N,N-dimethyl-p-phenylenediamine cation, it was supposed that D2h symmetry was broken down in alcohol solution and in glassy matrix, because the dimers had two Raman lines in the region of the intermolecular vibration.
Precipitation and Microflotation of Egg Albumin and Hemoglobin in the Presence of Dioctadecyldimethylammonmin Chloride
Authors: Nakayama Haruo , Itoh Kazuo , Shinoda K\={o}z\={o} , Matijevic Egon
Published: July 2006

Precipitation and microflotation of egg albumin and of hemoglobin was studied as a function of pH in the presence of dioctadecyldimethylammonium chloride (DOAC). The “DOAC concentration-pH” stability domains for both protein solutions (0.05 wt%) exhibited similar boundaries. Efficient separation by precipitation (more than 80% after 24 h) occurs at pH>5.0 for albumin and at pH>6.3 for hemoglobin. The same amount of removal by microflotation required 5 min under otherwise similar conditions. The DOAC concentration for optimal separation of proteins (from 0.05 wt% solutions) is 0.02 wt% at pH 6–8 for albumin and 0.015 wt% at pH 6.5–8 for hemoglobin. It is noteworthy that both proteins can be precipitated and also foam separated even in strongly alkaline media, such as at pH 12, where the usual flocculents (e.g., aluminum salts) cannot be employed. This work points out the usefulness of infinitely aggregating surfactants as microflotation agents.
Studies of Thermochemical Hydrogen Production. VII. Vapor-Liquid Equilibrium for Sulfur Dioxide–Bromine–Hydrobromic Acid–Sulfuric Acid–Water System
Authors: Ishikawa Hiroshi , Ishii Eiichi , Uehara Itsuki , Nakane Masanori
Published: July 2006

In order to eliminate SO2 from HBr gas produced by the reaction between SO2, Br2, and H2O, vapor-liquid equilibrium measurements of the Br2–H2SO4–H2O system saturated with HBr have been made over a wide range of the constituent concentrations. Experiments were carried out in a semi-flow system at 25 °C under atmospheric pressure. The relative concentration of HBr saturated in the liquid phase decreased from 0.31 to 0.05 [mol]/[mol] with an increase in the relative H2SO4 concentration from 0.0 to 0.40 [mol]/[mol]. The solubility of Br2, as defined by Henry’s law constant, varied from 1.1 to ca. 150 atm/mol/mol with the above-mentioned decrease in the HBr concentration. The relation between the partial pressure of SO2 in the gas phase and the composition of the liquid phase was found to be expressed by the following empirical formula: PSO2=K·CHBr·CH2SO4⁄CBr2, where the value of K is 8×10−4 when C is expressed as a relative molar concentration for each species in the liquid phase. The unconverted SO2 can be effectively removed by bringing the effluent gases from the reactor into contact with a HBr-saturated aqueous solution containing an excess of Br2.
Synthesis and Circular Dichroism Spectra of [Co(a)(gly)(1,4,7-triazacyclononane)]-type Complexes
Authors: Shimba Satoru , Fujinami Shuhei , Shibata Muraji
Published: July 2006

Complexes of the [Co(a)(gly)(tacn)]-type, where tacn represents 1,4,7-triazacyclononane and a is CN−, NO2−, NH3, NCS−, H2O, OH−, N3−, or Cl−, have been prepared and resolved. The CD spectra of these complexes have been measured. On the basis of the X-ray analysis of (−)589[Co(gly)(NH3)(tacn)]I2·H2O, the absolute configurations of the other complexes have been assigned by referring to the CD spectra. These complexes have exhibited a common CD pattern in the T1g-band region, and from this fact a criterion for the assignments of the absolute configurations for the complexes of the fac(D)-[Co(a)(BC)(DDD)]-type has been established.
Mixed-ligand Complexes of Cobalt(III) with 1-(2-Pyridylazo)-2-naphthol (PAN) and Diethylenetriamine (dien) or Triethylenetetramine (trien)
Authors: Mochizuki Katsura , Fujimoto Masatoshi
Published: July 2006

New mixed-ligand complexes [CoIII(pan)(dien)](ClO4)2·EtOH and [CoIII(pan)(trien)](ClO4)·NaClO4 were synthesized. The 1H NMR and the visible absorption spectra of these complexes were compared with those of the free ligand PAN and [CoIII(pan)2]Cl. A remarkable down-field shift observed in the 1H NMR signal for the proton H10 of the cobalt(III) complexes reflects the structural changes in the PAN molecule upon chelatering formation. The reaction between [CoIIICl2(trien)]Cl and PAN gave two kinds of products, which confirmed a strong tendency for the ligand PAN to behave as a planar terdentate ligand.
Spin-state Equilibria of the Nickel(II) Complexes of 2,12-Dimethyl 3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),2,11,13,15-pentaene Analogs in Water
Authors: Mochizuki Katsura , Fujimoto Masatoshi , Ito Haruko , Ito Tasuku
Published: July 2006

Spin-state equilibria between a singlet low-spin and a triplet high-spin species of the title complexes in water were investigated by means of electronic spectra. The equilibrium constants and the thermodynamic parameters, ΔH and ΔS, were evaluated from detailed analysis of the temperature-dependence of the electronic spectra. The electronic spectra of the singlet and the triplet species involved were also derived, from the same analysis. The formation of the triplet species was found to be exothermic, which reflects the predominant contribution of the exothermic change to the formation of nickel(II)–water bond over the contribution of the endothermic change in the bond length caused by the change in spin state. The absolute values of ΔS almost correspond to those expected for the effective liberation of two molecules of water in aqueous solution.
Synthesis of erythro- and threo-γ-Hydroxy-l-ornithines
Authors: Mizusaki Koichi , Yamamoto Hidefumi , Makisumi Satoru
Published: July 2006

γ-Hydroxy-Dl-ornithine was obtained from an alkaline hydrolysate of 2,5-diamino-4-pentanolide synthesized according to the method of Talbot et al. The amino acid preparation was found to be a racemic mixture composed of 34% erythro and 66% threo isomers by a new chromatographic assay. This assay is based on the conversion of the basic amino acid to a neutral amino acid by acetylation of the δ-amino group and the analysis of the resulting Nδ-acetyl derivative with an automatic amino acid analyzer by the ordinary method. Two diastereoisomers of γ-hydroxy-Dl-ornithine were separated by column chromatography on Dowex 50 and isolated as their crystalline hydrochlorides. Guanidination of the separated racemic diastereoisomers gave the corresponding diastereoisomeric γ-hydroxyarginines, hydrolysis of which with arginase yielded erythro- and threo-γ-hydroxy-Dl-ornithines.
Photo- and Thermally-induced Radical Rearrangement of 4,4-Dimethyl-5-cholesten-3β-ol Hypoiodite in the Presence of Mercury(II) Oxide and Iodine
Authors: Suginome Hiroshi , Maeda Norio
Published: July 2006

Irraidation of a benzene solution of hypoiodite of 4,4-dimethyl-5-cholesten-3β-ol (1) in the presence of mercury(II) oxide and iodine gave a mixture of products, from which 3α,5-epoxy-6β-iodo-A-homo-4-oxa-5α-cholestane (2%), 4,4-dimethyl-3-oxa-5-cholestene (3) (10%), and 4a,4a-dimethyl-3α,5-epoxy-A-homo-4-oxa-5α-cholest-6-ene (4) (4%) were isolated. The thermally-induced reaction on 1 conducted at 55–60 °C gave 3 and 4 in lower yields. The reaction with the use of lead tetraacetate-iodine reagent also gave a complex mixture, from which only 4 was obtained in 22% yield. The formation of 4,4-dimethyl-3-oxa-5-cholestene skeleton is parallel with the case of the photo- and thermally-induced reactions of hypoiodite of 3α,4,4-trimethyl-5-cholesten-3β-ol and appears to be particular with 5-cholesten-3β-ol bearing dimethyl groups at the C-4 under similar conditions. The formation is explained in terms of radical-induced decarbonylation of initially formed 4,4-dimethyl-2-formyl-3-oxa-5-cholestene.
Liposomal Membranes. III. Permeation of Pyrene-labeled Lecithin into Matrix of Liposomal Bilayers
Authors: Sunamoto Junzo , Nomura Tadashi , Okamoto Hiroshi
Published: July 2006

The permeation of a novel pyrene-labeled phosphatidylcholine, DPDL (1,2-bis[10-(1-pyrenyl)decanoyl]-sn-glycero-3-phosphatidylcholine), into the dipalmitoyl and egg phosphatidylcholine liposomes was studied. DPDL can adopt a sandwich conformation at the ground state, which comes in the fluorescence excimer emission. The fluorescent probe undergoes the initial rapid adsorption onto the liposome surfaces along with the instantaneous fluorescence enhancement followed by the relatively slow permeation into and diffusion in the liposomal bilayers. Through monitoring the relative quantum efficiency, Ie⁄Im (see text), during the permeation, suggestive information about the bilayer structure is obtained at least around the probe. The initial binding to and the subsequent diffusion in the membrane occur mostly as the monomeric form of the probe. At lower temperature without cholesterol the bilayer structure seems to be a lipid-separated conformation (Fig. 1 (c)) and above the chain-melting transition the bilayer seems to exist as a lipid-intimate conformation (Fig. 1 (b)). These results completely coincide with those obtained in our previous study on the codispersion of the probe with phospholipids (J. Sunamoto, et al., J. Am. Chem. Soc., 102, 1146 (1980)).
Enrichment and Spectrophotometric Determination of a Trace Amount of Chromium(VI) as the Diphenylcarbazide Complex on a Mixed Resin Prepared from Finely Divided Anion and Cation Exchangers
Authors: Ohzeki Kunio , Sakuma Toshiaki , Kambara Tomihito
Published: July 2006

A rapid and sensitive method has been developed for the determination of a trace amount of chromium(VI). It is based on the pre-concentration of chromium(VI) as the diphenylcarbazide (DPC) complex on a mixed resin prepared from finely divided anion and cation exchangers and the subsequent measurement of absorbance of the resin phase after collection on a filter paper as a uniform thin layer. The sensitivity of the method is approximately 100 times higher than the ordinary solution method using 1-cm cell. The extraction of chromium(VI) with tributyl phosphate followed by back extraction into water is effective for reducing the influence of interfering ions.
Dehydrooligopeptides. I. The Facile Coupling of α-Amino Acids with α-Dehydroamino Acids to Dehydrodipeptides
Authors: Yonezawa Yasuchika , Shin Chung-gi , Ono Yuji , Yoshimura Juji
Published: July 2006

N-Cbz- or N-Tos-α-dehydroamino acid (DHA) and its ester were prepared by the condensation of 2-oxo carboxylic acid or ester with benzyl carbamate or p-toluenesulfonamide. Subsequently, the N-protected DHA and its N-free ester thus obtained were coupled with several l-α-amino acid esters and N-protected (Boc or Cbz)-l-α-amino acid respectively by the usual peptide synthetic methods to give a number of different types of dehydrodipeptide. The configurations of all the new DHA and dehydrodipeptides obtained were shown to have (Z)-geometry.
New Methods for Stereoselective Synthesis of α-Alkylidene-γ-butyrolactones Using Monoanion of O-Ethyl S-(Tetrahydro-2-oxo-3-furanyl) Thiocarbonate and Dianion of α-Mercapto-γ-butyrolactone
Authors: Tanaka Kazuhiko , Uneme Hideki , Yamagishi Nobuyuki , Tanikaga Rikuhei , Kaji Aritsune
Published: July 2006

The lithium enolates of O-ethyl S-(tetrahydro-2-oxo-3-furanyl) dithiocarbonate and thiocarbonate were found to be efficient reagents for the stereoselective synthesis of α-alkylidene-γ-butyrolactones from carbonyl compounds. The dianion of α-mercapto-γ-butyrolactone was successfully generated by treatment of α-mercapto-γ-butyrolactone with 2.2 equivalents of lithium diisopropylamide in the presence of N,N,N′,N′-tetramethylethylenediamine at −78°C in THF. The dianion thus formed has been utilized for the efficient and stereoselective synthesis of α-alkylidene-γ-butyrolactones from carbonyl compounds.
Synthetic Studies via Arene-Metal Compounds. An Application to the Regioselective Synthesis of a Natural Phthalide
Authors: Uemura Motokazu , Nishikawa Naomi , Tokuyama Satoru , Hayashi Yuji
Published: July 2006

A naturally occuring methoxyphthalide derivative, a constituent of Othonna Cylindrica Dc, was synthesized by employing stereoselective carbonyl reduction of (η-arene)tricarbonylchromium complex and regioselective lithiation of 7-methoxy-2-(1-hydroxyethyl)-1-tetralol.
A Convenient One-step Preparation of Oxacyclanes by Dehydration of Diols over Alumina
Authors: Inoue Yoshihisa , Deguchi Shokichiro , Hakushi Tadao
Published: July 2006

Dehydration of 1,4-, 1,5-, or 1,6-alkanediols over alumina at 220–250 °C in a distillation apparatus gave the corresponding 5- to 7-membered oxacyclanes in good yield of 51–71%. Diethylene glycol also gave 1,4-dioxane in 49% yield, whereas attempted one-step synthesis of crown ethers from polyethylene glycols in a similar manner resulted in the predominant formation of 1,4-dioxane without any trace of crown ether.
Structural Studies on Fortimicins. III. The Crystal and Molecular Structure of Fortamine Dihydrochloride
Authors: Hirayama Noriaki , Shirahata Kunikatsu , Ohashi Yuji , Sasada Yoshio
Published: July 2006

Fortamine dihydrochloride, C8H18N2O4·2HCl, is obtained by the hydrolysis of fortimicin B with hydrochloric acid. The space group is C2 with a=16.109(2), b=10.047(1), c=8.603(1) Å, β=108.69(1)°, and Z=4. The structure was solved by the heavy atom method, and least-squares refinement using 1564 reflexions led to the final R value of 0.030. The ring conformation of fortamine dihydrochloride is an inversed chair form of fortamine. The chair form is significantly compressed to relax the non-bonded interactions between axial substituents.
The Structure of (Hydrogen Ethylenediaminetetraacetato)antimony(III) Dihydrate Sb(C10H13N2O8)·2H2O
Authors: Shimoi Mamoru , Orita Yoshinari , Uehiro Takashi , Kita Itsuro , Iwamoto Toschitake , Ouchi Akira , Yoshino Yukichi
Published: July 2006

The crystal and molecular structure of the title complex has been determined by X-ray diffraction using 1882 reflections. The crystal was orthorhombic, with the space group Pbn21; a=10.98(2), b=18.496(4), c=7.341(9), Z=4, Dx=1.99, Dm=1.98(2) g cm−3,μ(Mo Kα)=19.3 cm−1, and the final R value was 0.036. A distorted ψ-pentagonal bipyramid is formed around the central antimony(III) atom by two nitrogen and two oxygen atoms, together with a lone electron pair at the equatorial positions and two oxygen atoms at the axial positions. One of the Sb–O distances, 2.78 Å, is longer than the others (2.20(2) Å on the average), and it is determined that the carbonyl oxygen is essentially of the free-acid type and that its carbonyl oxygen is weakly coordinated. The splitting of the νas(COO) band of its infrared and Raman spectra shows the existence of both free and coordinated carboxyl groups. The 1H- and 13C-NMR results show that the antimony(III)–edta complex does not exchange with the free ligand in an aqueous solution at pH 1.5–3.5.
The Crystal and Molecular Structure of Palythine Trihydrate
Authors: Furusaki Akio , Matsumoto Takeshi , Tsujino Isami , Sekikawa Isao
Published: July 2006

The molecular structure of palythine, C10H16N2O5, has been confirmed by means of an X-ray crystal analysis of its trihydrate. The crystals are monoclinic, with two formula units in a unit cell with dimensions of a=10.499, b=12.812, c=5.322 Å, and β=98.53°; the space group is P21. 1377 unique intensity data were collected on a four-circle diffractometer with LiF-monochromated Cu Kα radiation. The structure was solved by the Monte Carlo direct method, using the 20 strongest reflections as a starting set, and was refined by the block-diagonal least-squares method. The final R value was 3.1%. The molecular structure thus obtained corresponds to that proposed by Tsujino et al. and Takano et al. on the basis of the chemical evidence. Palythine exists as a zwitter ion in the crystal. The palythine and water molecules are connected by twelve types of hydrogen bonds, forming a three-dimensional hydrogen-bonded structure.
The Determination of Kojic Acid Using the Stopped-flow Method
Authors: Tanigaki Hiroshi , Obata Hitoshi , Tokuyama Tai
Published: July 2006

A kinetic method of the determination of kojic acid with 2,6-dichlorophenolindophenol(DCIP) is described. The oxidized form of DCIP, reacting with kojic acid, changes to the colorless reduced form of DCIP. By spectrophotometrically measuring the rate of discoloration, the apparent first-order rate constant, kapp, and the second-order rate constant, k, were obtained. The determination of kojic acid in the fermentation medium is possible by using k the constant, even in the presence of various organic substances.
Preparation of Polynuclear (Diamine)telluratocobalt(III) Complexes
Authors: Hosokawa Yutaka , Shimura Yoichi
Published: July 2006

Penta- and hexa-nuclear condensates of mono(diamine)cobalt(III) complexes and tellurates have been prepared and some of the optically active isomers separated. They are [{Co(TeO6H4)(diamine)}(Te2O10){Co(TeO6H4)(diamine)}]6− (brown complexes) and [{Co(TeO6H4)(diamine)}(TeO6){Co(TeO6H4)(diamine)}]4− (blue complexes), where diamine=ethylenediamine, (R)-(−)-propylenediamine, and (R,R)-(−)-1,2-cyclohexanediamine. The structures have been determined from the visible and ultraviolet absorption and circular dichroism spectra; the electrostatic repulsion between cobalt(III) and tellurium (VI) atoms is considered in detail.
Synthesis and Characterization of Cobalt(II), Nickel(II), and Copper(II) Complexes with 2-Furancarbaldehyde Oxime
Authors: Kuma Hiro , Motobe Kyoji , Mori Wasuke , Yamada Shoichiro
Published: July 2006

Cobalt(II), nickel(II), and copper(II) complexes with 2-furancarbaldehyde oxime have been prepared and characterized mainly on the basis of electronic spectra and magnetic data. The cobalt(II) and nickel(II) complexes of the formula MX2(oxime)4 (X=Cl, Br) have been isolated. They are all six-coordinated, the oxime being coordinated as a unidentate through the nitrogen atom. Copper(II) forms complexes of the formula CuX2(oxime)2 (X=Cl, Br). Possible structures for these complexes are discussed.
The Total Synthesis of Neomycin C
Authors: Umezawa Sumio , Harayama Akihiko , Nishimura Yoshio
Published: July 2006

The total synthesis of the pseudo-tetrasaccharides antibiotic neomycin C is described, involving condensation of 6,3′,4′,5″-tetra-O-acetyl-1,3,2′,6′-tetra-N-(benzyloxycarbonyl)ribostamycin with 3,4-di-O-acetyl-2-deoxy-2-(p-methoxybenzylideneamino)-6-O-tosyl-α-d-glucopyranosyl bromide by a modified Koenigs-Knorr reaction.
Reaction of Dialkyl-substituted Alkynes with Carbon Dioxide Catalyzed by Nickel(0) Complexes. Incorporation of Carbon Dioxide in Alkyne Dimers and Novel Cyclotrimerization of the Alkynes
Authors: Inoue Yoshio , Itoh Yoshio , Kazama Haruo , Hashimoto Harukichi
Published: July 2006

Ni(cod)2–Ph2P(CH2)4PPh2 system (cod=1,5-cyclooctadiene) catalyzed the reaction of 3-hexyne, for example, with CO2 to give a CO2 incorporated product, i.e., tetraethyl-2-pyrone, in a fairly good yield together with novel two cyclotrimers of the alkyne having cyclopentadiene structures, i.e., pentaethyl-5-(1-propenyl)-1,3-cyclopentadiene and pentaethyl-5-allyl-1,3-cyclopentadiene. The novel two cyclotrimers were formed selectively on Ni(cod)2–PPh3 system under CO2, whereas under N2 the main trimer was hexaethylbenzene. A nickelacyclopentadiene intermediate has been proposed for the pyrone formation. The novel two cyclotrimers were also formed on the oligomerization catalyzed by a cationic nickel hydride complex, [HNi(Ph2PCH2CH2PPh2)2]OCOCF3, together with a novel dimer having a methylenecyclobutene structure, i.e., 1,2,4-triethyl-3-ethylidenecyclobutene. The effect of phosphine added and that of active-hydrogen compounds on the novel oligomerization are mentioned.
Carbon-13 NMR Chemical Shifts of Some Ruthenocenophanes and Ferrocenophanes
Authors: Senda Yasuhisa , Kamiyama Shin-ichi , Kasahara Akira , Izumi Taeko , Murakami Satoshi
Published: July 2006

The 13C NMR spectra of ruthenocenophanes, ferrocenophanes and their precursors were measured. The examination of molecular models for metallocenophanes and the spectral data offer some hints about the conformation of the molecules.
Synthetic Studies on Terpenic Compounds. XII. Selective Degradation of the Side Chain in Portulal
Authors: Tokoroyama Takashi , Matsuo Keizo , Kanazawa Reizo
Published: July 2006

Stepwise degradation of the side chain in portulal has been investigated in connection with synthetic studies. Selective cleavage of the double bond in the side chain was achieved by ozonolysis after protection of the endo-double bond by iodoetherification of the corresponding alcohol. Further degradation led to the formation of the γ-lactone via the δ-lactone.
Fluorescence Decay Studies of 9-Aminoacridine Bound to Polyriboadenylic Acid
Authors: Kubota Yukio , Motoda Yuko
Published: July 2006

The interaction of the mutagenic dye 9-aminoacridine (9AA) with polyriboadenylic acid (poly rA) was studied by both steady-state and transient fluorescence measurements. It was found that the fluorescence decay of 9AA bound to poly d(A-T) follows a single-exponential decay law but that the decay data of 9AA bound to poly rA can be well described as a sum of two-exponential functions. The fact that nanosecond time-resolved fluorescence spectra are independent of time suggests that the double-exponential decay may be attributed to different microenvironments at the binding sites. The decay parameters, fluorescence emission maxima, and fluorescence quantum yields obtained at acid pH differ from those obtained at neutral pH. The fluorescence behavior of 9AA is discussed in connection with the conformational change of poly rA.
Is O2*(a1Δg) Formed in the O+O3, H+O3, and NO+O3 Reactions ?
Authors: Washida Nobuaki , Akimoto Hajime , Okuda Michio
Published: July 2006

An attempt was made to detect O2*(a1Δg) in the reactions of O+O3, H+O3, and NO+O3 using a photoionization mass spectrometer. No significant signals for O2*(a1Δg) were observed in these reactions. From the results, it is concluded that less than 0.06, 0.001, and 0.002 of the reactive collisions result in the production of O2*(a1Δg) in the reactions of O+O3, H+O3, and NO+O3 respectively, all at 298 K. The failure to observed O2*(a1Δg) in these reactions was discussed by means of correlation diagrams and GVB model representations.
Paramagnetic Cobalt(III) Complexes with Organic Ligands. V. The Isolation and Properties of Salts of the Paramagnetic Bis(2,2′-bipyridine)(5-nitrosalicylato)cobalt(III) and of the Paramagnetic “β1 and β2”-Isomers of the 5-Nitrosalicylato(triethylenetetramine)cobalt(III) and Their Derivatives
Authors: Yamamoto Yoshihisa , Toyota Eiko , Mitsudera Naoto
Published: July 2006

The picrate of the paramagnetic, [Co(5-NO2sal)(bpy)2]2+, has been isolated from a reaction mixture of picric acid, 60% nitric acid, and bis(2,2′-bipyridine)(salicylato)cobalt(III) chloride trihydrate, [Co(sal)(bpy)2]Cl·3H2O, which had been prepared from salicylic acid and cis-bis(2,2′-bipyridine)dichlorocobalt(III) chloride dihydrate. The absorption spectrum and the stability of an aqueous solution of the picrate of the paramagnetic, [Co(5-NO2sal)(bpy)2]2+, were somewhat different from those of complexes of the paramagnetic, [Co(5-NO2sal-R)(NH3)4]2+ (R: H, CH3). Several complexes of the paramagnetic, β1-5-nitrosalicylato-, β2-5-nitrosalicylato-, and β2-3-methyl (and 4-methyl)-5-nitrosalicylato(triethylenetetramine)cobalt(III) have, analogously, been isolated from reaction mixtures of 60% nitric acid and β1-salicylato-, β2-salicylato, or β2-methylsalicylato(triethylenetetramine)cobalt(III) chloride hydrate respectively. Their β1 and β2-isomeric forms were proved by a study of their IR and 1H-NMR spectra. From the IR, NMR, and the magnetic susceptibility measurement results, these compounds are considered to have the paramagnetic complex, [Co(5-NO2sal)L]2+(L: (NH3)4, (en)2, (bpy)2, and trien), and the electron hole is considered to delocalize over the chelate ring containing the cobalt atom and the 5-nitrosalicylato ligand.
Polarographic Study on the Transportation of Oxygen by Perfluorocarbon Emulsion as Artificial Blood
Authors: Hayashi Katsumi , Takagi Masanosuke
Published: July 2006

Restrictive factors of oxygen release from dispersed particles of perfluorocarbon (PFC) in a form of emulsion have been studied by polarographic reduction currents of oxygen in the emulsion. The oxygen reduction currents in PFC emulsion in open system increased linearly with the volume fraction of PFC component, and were diffusion-controlled. The increase of current was ascribed to the increase of oxygen supply to the electrode from PFC particles in the emulsion. Analyzing the oxygen reduction current due to PFC particles, the ratio of diffusion coefficients of oxygen inside and outside PFC particle (D1⁄D0) and the oxygen partition coefficient between the both sides (C1⁄C0) were obtained. The release of oxygen from PFC particle was rate-determined by oxygen diffusion in the particle and the diffusion itself was determined by inner viscosity of PFC particle. The surfactant layer of PFC particle did not play any appreciable role such as permeability barrier for oxygen transportation.
Potentiometric Study on the Complex Formation of Cobalt(II) Ion with Ethylenediamine-N-acetic Acid, Diethylenetriamine, and Iminodiacetic Acid
Authors: Ohsaka Takeo , Oyama Noboru , Matsuda Hiroaki
Published: July 2006

The formation constants of Co(II)–ethylenediamine-N-acetate (edma), –diethylenetriamine (dien) and –iminodiacetate (ida) complexes were determined by potentiometric titration in 1.0 M NaClO4 solution at 25 °C. The following results were obtained. Edma: logβ101=7.51, logβ102=14.05: dien: logβ101=9.34, logβ102=16.89; ida: logβ101=6.54, logβ102=11.95, βpqr being the overall formation constant defined in the text. The relative effects of amino and carboxyl groups on the affinity of ligands to Co(II) ion are discussed.
Lithiation of Alkoxyalkyl Phenyl Sulfones. New Approach to Acyl Anion Synthesis
Authors: Tanaka Kazuhiko , Matsui Syuichi , Kaji Aritsune
Published: July 2006

(1-Ethoxyethoxy)methyl and 1-(1-ethoxyethoxy)ethyl phenyl sulfones undergo metalation with LDA in THF in the presence of HMPA. The resulting lithium salts were easily alkylated with various alkyl halides and hydrolyzed under mild conditions to give the corresponding carbonyl compounds. The new synthetic method for the preparation of aldehydes and ketones employing these carbanions has been developed.
A Catalytic Effect of Amines on the Reaction of Arenesulfinic Acids with N,N′-Thiodiphthalimide
Authors: Abe Yasuo , Horii Toyokazu , Oka Kunio , Kawamura Shunichi , Nakabayashi Takeshige
Published: July 2006

In the presence of catalytic amounts of several amines, N,N′-thiodiphthalimide has been allowed to react with one or two equiv. of arenesulfinic acids in dichloromethane, thus giving N-(arylsulfonylthio)phthalimides or bis(arenesulfonyl) sulfides respectively in good yields. The arenesulfinate anion seems to be a better nucleophile against N,N′-thiodiphthalimide than arenesulfinic acid. The mechanism of the catalytic reaction will be discussed.
The Acetylation of Toluene and Benzene with Acetyl Chloride and Bromide and Acetic Anhydride Catalyzed by Calcined Iron Sulfate Activated by Exposure to a Mixture of Benzyl Chloride and the Aromatics
Authors: Arata Kazushi , Hino Makoto
Published: July 2006

The acetylations of toluene and benzene with acetyl halides and acetic anhydride were studied over catalysts prepared by heat-treating FeSO4 in air, followed by activation on exposure to benzyl chloride in toluene or benzene at 40–80 °C for 1 h, together with FeCl3 and AlCl3. The sulfates treated at 700 and 800 °C showed high activity. The former, activated at 60 °C, gave 68% methylacetophenones, and the latter, more than 90%, with an isomer distribution of 2% ortho-, 1% meta-, and 97% para-form in the reaction of toluene with acetyl halides at room temperature, while the maximum yield was 24% with FeCl3 and 29% with AlCl3. A high yield of acetophenone, 77%, was obtained over the FeSO4 (700 °C) catalyst in the reaction of benzene with acetyl bromide at 60 °C for 1 h. The present catalysts were also highly active for the acetylation of toluene with acetic anhydride; e.g., 55% methylacetophenones were obtained over the FeSO4 (800 °C) catalyst at 100 °C for 5 h. FeCl3 and AlCl3 gave quite low yield compared with the present catalysts.
The Crystal Structure of N-(t-Butoxycarbonyl)-l-methionylglycine Benzyl Ester
Authors: Yamane Takashi , Umemura Takashi , Kojima Tadao , Yamada Yasuyuki , Ashida Tamaichi
Published: July 2006

The crystal structure of N-(t-butoxycarbonyl)-l-methionylglycine benzyl ester has been determined. The crystal data are: P21, a=15.884(4), b=5.083(2), c=13.296(3) Å, β=94.54(2)°, Z=2. The final R is 0.055 for 1518 reflections. In the methionyl residue the Cα–Cβ bond is longer than the Cβ–Cγ bond. The tendency is consistent with that found in the other methionine compounds. The methionyl side chain has the most stable trans zig-zag conformation (χ1=−73.2, χ2=175.3, and χ3=174.9°). The peptide main chains are packed in a parallel β-sheet structure, the torsion angles (φ,ψ) of the methionyl residue being (−110.6, 108.3°).
Liquid Crystal Formation in Binary Systems. I. An Interpretation of the Phase Diagrams of the Azoxydianisole–Schiff Base Systems
Authors: Araya Kotaro , Matsunaga Yoshio
Published: July 2006

In order to confirm the presence of a transition at the temperature where the liquid crystal-isotropic liquid transition curve in the nematogen-rich region is met by the other transition curve, five binary systems comprising azoxydianisole (AA) and a Schiff base were examined by means of differential scanning calorimetry. A small but sharp endothermic peak due to a phase change is observable at the expected temperature upon heating, provided that it is well separated from the eutectic temperature. When the above-mentioned curve intersects the solid-liquid transition curve on the Schiff base-rich side, a liquid crystal coexisting with the solid base is transformed into an isotropic liquid coexisting with the same solid at this temperature. The presence of a nematic phase below this temperature could be demonstrated by measuring the separation of the outer hyperfine extrema in the ESR spectrum of bis(acetylacetonato)oxovanadium(IV) dissolved in the mixtures. The sequence of the transformation is entirely different when the intersection occurs on the AA-rich side. However, attempts to confirm the transition of the latter type by ESR were not successful.
Solubilization of Coal by a Treatment with Butylzinc Compounds under Mild Conditions. —Active Species in a Zinc-Butyl Iodide System for Coal Solubilization—
Authors: Yoneyama Yoshiharu , Kato Tsutomu , Mizutani Makoto , Gonda Kiyoshi
Published: July 2006

To elucidate the effectiveness of a treatment of coal with butylzinc compounds on coal solubilization, Yubari coal was treated with Bu2Zn and/or BuZnX (X = Cl, Br, I) in the presence or absence of alkyl halide (RX). Both the treatment using Bu2Zn or BuZnI and that with a combination of Bu2Zn and RX (X = Cl, Br) were not very effective for coal solubilization, whereas the combination of Bu2Zn, BuZnX (X = Cl, Br, I) and BuX (X = Cl, Br, I) was very effective. The best yield of a benzene-soluble product (BS) of Yubari coal was 96%. The 13C NMR and FT-IR spectra of each BS fraction of Yubari coal treated with 13CH3I, CH3I, and BuI, respectively, in the presence of BuZnI and Bu2Zn showed that the alkyl and butyl groups from RX and butylzinc compounds were introduced into the BS fractions according to addition and substitution toward aromatic moieties. The addition of alkyl groups to aromatic moieties seemed to be more effective coal solubilization than the substitution of alkyl groups. These results indicate that BuZnI, Bu2Zn, and BuI are indispensable species in the Zn/BuI system for effective coal-solubilization.
Selective Hydrogenation of Alkynes Catalyzed by Metallic Nickel and Modifier
Authors: Sakai Mutsuji , Takai Yoshihiro , Mochizuki Hiroki , Sasaki Ken , Sakakibara Yasumasa
Published: July 2006

Under an atmospheric pressure of hydrogen alkynes were successively hydrogenated to give alkanes via (Z)-alkenes with the metallic nickel catalyst, which was easily prepared by reaction of nickel bromide with zinc powder. Phosphines and diamines as catalyst modifiers were effective for the partial hydrogenation of alkynes.
Belief in psychic ability and the misattribution hypothesis: A qualitative review
Authors: Wiseman Richard , Watt Caroline
Published: July 2006

This paper explores the notion that people who believe in psychic ability possess various psychological attributes that increase the likelihood of them misattributing paranormal causation to experiences that have a normal explanation. The paper discusses the structure and measurement of belief in psychic ability, then reviews the considerable body of work exploring the relationship between belief in psychic ability, and academic performance, intelligence, critical thinking, probability misjudgement and reasoning, measures of fantasy proneness and the propensity to find correspondences in distantly related material. Finally, the paper proposes several possible directions for future research, including: the need to build a multi‐causal model of belief; to address the issue of correlation versus causation; to resolve the inconsistent pattern of findings present in many areas; and to develop a more valid, reliable and fine‐grained measure of belief in psychic ability.
Modulation of distraction in ageing
Authors: Ryan Jennifer D. , Shen Jiye , Reingold Eyal M.
Published: July 2006

A cueing paradigm was employed to examine modulation of distraction due to a visual singleton. Subjects were required to make a saccade to a shape‐singleton target. A predictive location cue indicated the hemifield where a target would appear. Older adults made more anticipatory saccades than younger adults, and were less accurate for making an eye movement in the vicinity of a target. However, younger and older adults likewise benefited from the cue; distraction was reduced when the distractor singleton appeared in an uncued hemisphere. The ability to compensate for problems with distraction in older and younger adults through use of the precue suggests that attention to a general region of space, rather than a specific location, may be enough to modulate distraction.
Driving aggression in forensic and non‐forensic populations: Relationships to self‐reported levels of aggression, anger and impulsivity
Authors: Smith Paul , Waterman Mitch , Ward Nic
Published: July 2006

A series of four questionnaires — the Buss‐Perry Aggression Questionnaire (AQ), the Barratt Impulsivity Scale (BIS‐11), the Driving Anger Scale (DAS) and a Driving Violence Inventory (DVI) — were administered to a sample of 473 British drivers consisting of undergraduates (N=185), members of the public (N=106) and offenders (N=182) serving sentences in closed prisons in England (violent=82, non‐violent=100). Offenders consistently rated acts of driving aggression as less severe compared with other drivers. Offender attributions of driving violence differed to other drivers in that they were equally likely to perceive obscene gesturing as high or low intensity responses; they also viewed assault as a high intensity response whereas members of the public rated it more severely. Trait levels of anger and aggression were the predictors of driving violence in all groups but previous aggressive behaviour was only a predictor for the offenders. Gender and age were found to be predictors of aggressive driving in non‐offenders. Even with the effects of age controlled, offenders (and violent offenders in particular) scored higher on measures of driving anger and aggression. These data suggest that offenders differ in their perceptions of aggressive behaviours experienced in everyday driving and as a consequence are more likely to commit acts that other drivers perceive as violent. As offenders are known to display similar perceptual biases in other domains, identified as precursors to their aggressive behaviour, it seems likely that experience effects (as reflected in the trait measures) underpin differences in driving aggression between offenders and non‐offenders.