bluuebunny/crossref_metadata_2025 huggingface dataset:
Solubility Measurements of Benzene and the Alkylbenzenes in Water by Making Use of Solute Vapor
Authors: Sanemasa Isao , Araki Masatake , Deguchi Toshio , Nagai Hideo
Published: July 2006

Aqueous solubilities of benzene and of alkylbenzenes, toluene, ethylbenzene, propyl- and isopropylbenzene, (o-, m-, and p-) xylene, and (1,2,3-, 1,2,4-, and 1,3,5-) trimethylbenzene, have been measured. An apparatus is described which provides a convenient means of obtaining aqueous solutions saturated with solute vapor. The method involves introducing solute vapor, which is in equilibrium with a liquid solute, into water and circulating it in a closed system. This method has three principal advantages: (1) The solubility equilibrium can be attained within 3 min, (2) it can be determined whether the solubility obeys Henry’s law, and (3) based on Henry’s law, solutions of any desired concentrations of solute at a given temperature of water can be easily prepared.
Characterization of trans(O)-N,N′-Ethylenebis(S-methyl-l-cysteinato)cobalt(III) Perchlorate and the Absolute Configuration of the Complex Determined by X-Ray Analysis
Authors: Okamoto Ken-ichi , Isago Takashi , Ohmasa Masaaki , Hidaka Jinsai
Published: July 2006

A cobalt(III) complex with the sexidentate ligand, N,N′-ethylenebis(S-methyl-l-cysteine), was newly synthesized and chromatographically isolated. Of two possible geometrical isomers, trans(O) and trans(N), one isomer was formed selectively. The dark-red crystals are orthorhombic, space group P212121, a=9.055(2), b=22.123(7), c=17.111(4) Å, and Z=8. The structure was solved by the direct method and refined to R=0.066 for 2380 nonzero reflections. The complex is trans(O) isomer and the crystal consists of two kinds of complex cations with respect to the absolute configurations of the coordinated asymmetric sulfur atom. One takes an S(S),S(S) configuration and the other an R(S),S(S) one. The changes in configuration between the asymmetric sulfur atoms in the crystal and those in aqueous solution are discussed on the basis of NMR (13C and 1H) spectral studies.
Preparation and Characterization of Dichlorobis(N-alkylsalicylideneaminato)manganese(IV) Complexes
Authors: Matsushita Takayuki , Hirata Yoshihisa , Shono Toshiyuki
Published: July 2006

The chlorobis(N-alkylsalicylideneaminato)manganese(III) complexes, MnIII(N-Rsai)2Cl, react with hydrogen chloride to give the corresponding dichloromanganese(IV) complexes, MnIV(N-Rsai)2Cl2, as deep green crystals; R can be n-C3H7, n-C4H9, i-C4H9, n-C6H13, c-C6H11, n-C8H17, n-C12H25, n-C18H37, CH2C6H5, or CH2CH2C6H5. These complexes were characterized by the magnetic susceptibilities, electronic spectra, infrared spectra, and cyclic voltammograms. The complexes (R=n-C12H25 and n-C18H37) are found to be stable toward water in the solid state. A trans, six-coordinate configuration is proposed for these Mn(IV) complexes on the basis of the infrared spectra.
Binuclear Metal Complexes. XLIV. Crystal Structures and Magnetic Properties of Alkoxo-oxygen Bridged Binuclear Copper(II) Complexes with 2-[2-(Dialkylamino)ethylthio]ethanol
Authors: Mikuriya Masahiro , Okawa Hisashi , Kida Sigeo
Published: July 2006

Six binuclear copper(II) complexes with 2-[2-(dialkylamino)ethylthio]ethanol, Cu2{R2N(CH2)2S(CH2)2O}2X2 (abbreviated as Cu(R-nso)X, where R=CH3, C2H5, n-C3H7, n-C4H9; X=Cl, Br), were characterized by magnetic susceptibility (80–300 K). The temperature dependence of the magnetic susceptibilities of Cu(C2H5-nso)Cl and Cu(n-C4H9-nso)Cl can be interpreted by the Bleaney-Bowers equation based on a binuclear structure, while the magnetic data of the other complexes do not obey the Bleaney-Bowers equation. X-Ray structure analyses have revealed that the structures of all the complexes consist of discrete alkoxo-bridged binuclear units, and the coordination geometry of each copper atom is a distorted square pyramid with two oxygen, one sulfur and one chlorine or bromine atoms in the basal plane and a nitrogen atom in the apical position. The major structural difference corresponding to the different magnetic behaviors was attributed to the conformations of the chelate ring (Remark: Graphics omitted.).
A Study of the Rapid Anomerization of Poly-O-benzyl-β-d-glucopyranosides with Titanium Tetrachloride
Authors: Koto Shinkiti , Morishima Naohiko , Kawahara Reiko , Ishikawa Katsuhiko , Zen Shonosuke
Published: July 2006

Titanium tetrachloride rapidly anomerizes methyl 2,3,4,6-tetra-O-benzyl-β-d-glucopyranoside in dichloromethane at 25 °C. Evidence for the proposal that the benzyloxymethyl group on C-5 and the ring oxygen of the glucoside cooperate to prompt the reaction is described. The reagent anomerizes the interglycosidic linkage of several disaccharide derivatives.
Micellar Effects on the Co-catalysis of Magnesium Ion and Imidazole for the Hydrolysis of Phenyl Phosphatosulfate
Authors: Eiki Toshio , Tagaki Waichiro
Published: July 2006

The effects of Mg2+ ion and imidazole were examined on the hydrolysis of phenyl and p-decylphenyl phosphatosulfate (PPS and DPPS) in the presence of micelle of sodium dodecyl sulfate (SDS). It was observed that Mg2+ ion and imidazole increased the rates of hydrolysis cooperatively and the rate enhancement was much larger in the case of DPPS than in the case of PPS. The difference in the reactivities of two esters was discussed in terms of micellar effects.
3β,6β-Bis(acyloxy)furanoeremophilan-14-als and -14-oic Acids from Syneilesis palmata (Thunb.) Maxim.
Authors: Kuroda Chiaki , Murae Tatsushi , Tada Masahiro , Nagano Hajime , Tsuyuki Takahiko , Takahashi Takeyoshi
Published: July 2006

Structural studies of four new sesquiterpenes, 3β-angeloyloxy-6β-(3-methylbutanoyloxy)- and 3β,6β-bis(angeloyloxy)furanoeremophilan-14-als and 3β-angeloyloxy-6β-(3-methylbutanoyloxy)- and 3β-angeloyloxy-6β-(3-methylpentanoyloxy)furanoeremophilan-14-oic acids, together with 3β,6β-bis(angeloyloxy)furanoeremophilan- 14-oic acid from Syneilesis palmata (Thunb.) Maxim, are described.
Molecular Mechanical Calculation on Cyclodextrin Inclusion Complexes. I. The Structures of α-Cyclodextrin Complexes Estimated by van der Waals Interaction Energy Calculation
Authors: Matsui Yoshihisa
Published: July 2006

The geometries of inclusion complexes of α-cyclodextrin (α-CD) with krypton, methanol, 1-propanol, and p-nitrophenol were estimated on the basis of the calculation of energies (Evdw) due to the van der Waals interactions between the CD and the guest molecules. The Evdw values were computed by the use of Hill’s potential equation. A spatial relationship at which the Evdw value became minimal was in good agreement with that observed by X-ray crystallography for such a guest molecule as 1-propanol or p-nitrophenol, which is large in size and less polar. On the other hand, a significantly large deviation was found between the observed and the calculated geometries of the inclusion complex in such polar and/or small guest molecules as methanol and krypton.
Crystal Structure and Photochemistry of Isopolymolybdates. I. The Crystal Structures of Hexakis(propylammonium)heptamolybdate(VI) Trihydrate and Hexakis(isopropylammonium)heptamolybdate(VI) Trihydrate
Authors: Ohashi Yuji , Yanagi Kazunori , Sasada Yoshio , Yamase Toshihiro
Published: July 2006

The crystal structures of (NH3CH2CH2CH3)6[Mo7O24]·3H2O and (NH3CH(CH3)2)6[Mo7O24]·3H2O have been determined by X-ray analysis. The crystal of the propylammonium salt is triclinic; the space group is P\bar1; Z=2, with a=14.118(2), b=15.977(2), c=11.368(1) Å, α=90.23(1), β=93.00(1), γ=111.79(1)°. That of the isopropylammonium salt is monoclinic; the space group is P2/n; Z=4, with a=23.904(6), b=10.504(1), c=20.652(9) Å, and β=115.40(2)°. The structures were deduced by the direct method and refined by the block-diagonal least-squares technique. The final R values were 0.035 for 8084 observed reflections of the former and 0.060 for 9934 of the latter. The heptamolybdate anion of the two crystals has an approximate 2mm symmetry and its structure is similar to that observed in the crystals of the ammonium, potassium and sodium salts. The propyl- and isopropylammonium cations form some hydrogen bonds to the bridging oxygens of the heptamolybdates. Such hydrogen bonds play an important role in the UV-induced photochromism of these crystals.
Structure and Properties of Diaquabis(ethylthioacetato)copper(II), [Cu(C4H7SO2)2(H2O)2]
Authors: Ogawa Takashi , Shimoi Mamoru , Ouchi Akira
Published: July 2006

The crystal and molecular structure of the title complex has been determined by the X-ray diffraction method. The crystal was triclinic, space group P\bar1, a=7.554(1), b=9.001(1), c=5.345(1) Å, α=104.83(1), β=99.20(1), γ=71.02(1)°, Z=1, DX=1.684(1), Dm=1.69(1) Mg m−3, μ(Mo Kα)=2.03 mm−1, and the final R value was 0.030 for 1818 reflections. The molecular arrangement has a center of symmetry and has a slightly distorted octahedral configuration around the central copper(II) atom; each ethylthioacetato ligand forms a chelate ring by coordinating through a sulfur atom and a carboxyl oxygen atom, and two water molecules are also coordinated to the central metal. The solid complex is deep green, different from the diaquabis(alkylthioacetato)copper(II) complexes of the higher alkyl groups (number of C≥3), and it is likely due to the CT band caused by the strong copper–sulfur bond in the complex.
Symmetrized Local Mode Analysis of CH2 Stretching Mode in 1,1-Dichloroethylene
Authors: Tamagake Keietsu , Hyodo Shi-aki , Fujiyama Tsunetake
Published: July 2006

A symmetrized local mode (SLM) model based on the two dimensional Morse oscillator was developed and applied to the analysis of the spectrum of the CH stretching modes in 1,1-dichloroethylene in the range of 3000–17000 cm−1. More than twelve absorption peaks were assigned in terms of the mixed SLM states. The calculated frequencies with finally determined parameters: ωe=3191.6 cm−1, ωeχe=57.63 cm−1, and f12=2170 cm−1 agreed well with the observed ones. The kinetic coupling was found to be more responsible for the mixings between SLM states than the potential coupling. The observed intensity data were analyzed by the use of the obtained mixing coefficients and the two dimensional dipole moment function parameters: M1, M2, M12, and θ. The finally determined dipole moment function parameters were: M1=−0.290 D Å−1, M2=−0.875 D Å−2, M12=−0.386 D Å−2, and θ=38.4°. Careful examination of the influence of M12 upon the integrated intensities clarified the validity of the one dimensional intensity analysis of our preceding work. An SLM representation was confirmed to be useful for the systematic analysis of the CH stretching spectrum through the fundamental and the high v local mode bands which include highly structured low v summation bands. An SLM representation was also found to be convenient for making a simple correlation between local mode and normal mode pictures.
Interaction between Ethidium Bromide and Various Polyelectrolytes and DNA with Emphasis on Spectral Characteristics and Binding Curves of the Bound Dye
Authors: Yamaoka Kiwamu , Matsuda Takumi , Shiba Daisuke , Takatsuki Mineo
Published: July 2006

Visible and ultraviolet absorption spectra of ethidium bromide (EB) were measured by the optical titration method in the presence of each of three synthetic polyelectrolytes—sodium salts of poly(p-styrenesulfonate) (NaPSS), polyphosphate (NaPP), and polyacrylate (NaPA)—and native and heat-denatured DNA at 25 °C. By use of the principal component analysis (PCA) method, the number of EB species present in each EB–polymer system was determined to be two, i.e., free and bound EB, in the range of the polymer residue-to-EB ratio between zero and about one. The spectrum and the fraction of EB species bound to each polymer were determined by the extended PCA method. The bound-EB spectra are bathochromic and hypochromic relative to the spectrum of free EB, but they show no metachromasy band. The apparent binding constants Ka for EB bound to polymers are in the order of NaPSS>denatured DNA>NaPP>NaPA\fallingdotseqnative DNA.
Relation between Exchange Interaction and Crystal Structure of Verdazyl Radicals. As Studied by Means of McConnell’s Spin Density Hamiltonian
Authors: Azuma Nagao
Published: July 2006

The exchange interactions in four kinds of verdazyl crystals, 2,4,6-triphenylverdazyl (TPV), 2,4,6-triphenyl-3-methylverdazyl (MeTPV), 2,4,6-tri-p-tolylverdazyl (TTV), and 2,6-di-p-tolyl-4-phenylverdazyl (DTPV), have been studied by means of McConnell’s spin density Hamiltonian. The calculated exchange parameters, J, have been compared with the experimental values derived from the magnetic susceptibilities. The observed order of J’s J⁄k=−5.4 (TPV), −9.1 (MeTPV), −11.1 (DTPV), and 0–−0.3 K (TTV), can be qualitatively explained by the following equation:

J∝\undersetijΣ (−1⁄rij)ρilρjl+1,

where ρil and ρjl+1 are π-spin densities on atoms i and j of the l-th and (l+1)-th molecules in the crystallographic column and rij is the interatomic distance between atoms i and j. The magnetic susceptibility data of MeTPV and TTV between 1.6 and 300 K are presented and interpreted with the Heisenberg linear chain model. The susceptibility of DTPV is re-interpreted in the same framework as above.
Paramagnetic Cobalt(III) Complexes with Organic Ligands. VII. The Isolation and Properties of Paramagnetic Tetraammine(5-nitrososalicylato)cobalt(III) Complexes
Authors: Yamamoto Yoshihisa , Kudo Hiroko , Mori Masayasu , Konno Hidetaka
Published: July 2006

The title paramagnetic complexes, [Co(5-NOsal)(NH3)4]X2·nH2O (X2=Cl(NO3), Cl2·HCl, and Cl2), all brown in color, have been isolated and characterized by analytical, spectroscopic, and magnetic methods. The effective magnetic moments of the complexes are 1.6–1.8 BM, and the absorption spectra have two peaks, at 387 and 518 nm. In the XPS of the complex, the cobalt 2p peaks have satellites, and the peak of the nitrogen Is could be deconvoluted to that of NH3 nitrogen at 400.2 eV and to that of NO nitrogen at 402.2 eV. This binding energy of the NO nitrogen of the complex is different from that (405.6 eV) of the NO2 nitrogen of the green Paramagnetic tetraammine(5-nitrosalicylato)cobalt(III) complexes, [Co(5-NO2sal)(NH3)4]X2, and establishes the difference between these two series of complexes.
A Hypervirial Theorem Aspect of Koopmans’ Theorem
Authors: Isihara Makoto
Published: July 2006

Koopmans’ theorem is interpreted as a hypervirial theorem requirement; the implication of Koopmans’ theorem is thereby clarified. A hypervirial theorem standpoint gives a physically sound ground to a leading correction of Koopmans’ relation. Attention is paid to the orbital ambiguity associated with the correction, a possible utilization of the ambiguity being suggested.
Cobalt(III) Complexes with Tripodlike Quadridentate Ligands. II. Preparations, Absorption Spectra and Circular Dichroism of (Amino carboxylato or 1,2-diamine)[N,N-bis(2-aminoethyl)glycinato]cobalt(III) Complexes
Authors: Akamatsu Keiji , Komorita Takashi , Shimura Yoichi
Published: July 2006

Four glycinato, six l-alaninato, and three (R)-propylenediamine cobalt(III) complexes of a tripodlike quadridentate ligand, N,N-bis(2-aminoethyl)glycinate have been prepared. The geometrical configurations are assigned on the basis of their absorption and circular dichroism spectra, 1H-NMR spectra, the elution behavior in ion-exchanger column chromatography, and the optical resolution of chiral isomers. The absolute configurations of the chiral complexes are tentatively assigned and the characteristics of the tripodlike ligand are discussed.
Enthalpy of Oxidation-Reduction for the Ethylenediaminetetraacetatocobaltate(III/II) Couple Relative to the Hydrogen Ion Formation
Authors: Doi Kunio
Published: July 2006

Oxidation of ethylenediaminetetraacetatocobaltate(II) with permanganate ion has been studied spectrophotometrically. The first step in the oxidation is the rapid formation of [CoIII(edta)(H2O)]−, followed by the ring closure reaction of the complex to [CoIII(edta)]−. On the basis of the spectrophotometric result, the enthalpies of the reactions, [CoII(edta)]2−+1/5 MnO−4+8/5 H+→[CoIII(edta)(H2O)]−+1/5 Mn2++4/5 H2O and [CoIII(edta)(H2O)]−→[CoIII(edta)]−+H2O, have been determined at 25 °C and at an ionic strength of 0.1 by a direct thermometric titration procedure. The enthalpy of the reaction, [CoIII(edta)]−+1/2 H2\ightleftharpoons[CoII(edta)]2−+H+, has been calculated by combining them with some other calorimetric data. The thermodynamic functions for formation of the [CoIII(edta)]− complex are estimated from the values so far reported. At 25 °C and at an ionic strength of 0.1 ΔG=−242 kJ mol−1, ΔH=−101 kJ mol−1, and ΔS=474 J mol−1 K−1.
Solvent Extraction Study on the Hydrolysis of Tracer Concentrations of Bismuth(III) in Perchlorate and Nitrate Solutions
Authors: Hataye Itsuhachiro , Suganuma Hideo , Ikegami Hisashi , Kuchiki Takashi
Published: July 2006

The backward solvent extraction with dithizone-carbon tetrachloride solutions was used to examine the chemical species of Bi(III). A tracer concentration of Bi(III) (<10−7 mol dm−3) was found to exist in the form of Bi3+, Bi(OH)2+, Bi(OH)2+, and Bi(OH)3 in 1.0 mol dm−3 (H,Na)ClO4, and Bi(NO3)n3−n, Bi(OH)(NO3)n2−n, Bi(OH)2(NO3)n1−n, and Bi(OH)3(NO3)nn− in 1.0 mol dm−3 (H,Na)NO3 solutions depending on the acidity of the solutions. The constants of successive hydrolysis, β1, β2, and β3, were calculated by using the distribution data. The resulting logβ1, logβ2, and logβ3 values were 12.0, 22.9, and 33.9 for 1.0 mol dm−3 (H,Na)ClO4 solution, and 11.9, 22.7, and 33.2 for 1.0 mol dm−3 (H,Na)NO3 solution, respectively. The chemical composition of the extracted species was most probably Bi(HDz)3.
The Reaction of Bis(dimethylglyoximato)(pyridine)cobalt(I), Cobaloxime(I), with 2-(Allyloxy)ethyl Halides and the Photolysis of the Resulting Organo-cobaloximes
Authors: Okabe Masami , Tada Masaru
Published: July 2006

The reactions of 2-(allyloxy)ethyl halides with cobaloxime(I) gave (tetrahydro-3-furanyl)methylcobaloximes via an electron transfer from cobaloxime(I) to the halides to give radical anions. The rupture of a halide ion to give an organic radical and the ring closure to give a (tetrahydro-3-furanyl)methyl radical are followed by the radical coupling between the organic radical and the cobaloxime(II). The structures of the organo-cobaloximes were determined by the analyses of the photolysis products under aerobic or anaerobic conditions.
An MO Theoretical Study of the Photochemical Reaction of Alkanenitronate Anions to Form Hydroxamic Acids
Authors: Kikuchi Osamu , Kanekiyo Takazumi , Tanaka Seiji , Naruchi Kiyoshi , Yamada Kazutoshi
Published: July 2006

The reaction mechanism of the photochemical reaction of alkanenitronate anions to form hydroxamic acids was explored on the basis of the potential energy curves obtained by means of MINDO/3 CI calculations. The O-oxaziridine was calculated to be not an intermediate, but an unstable transient species in this photoreaction. This is different from the photoisomerization of methyleneamine N-oxide derivatives into the corresponding amides, in which the oxaziridine is considered to be an intermediate. The proposed reaction mechanism elucidates well the regioselectivity observed in the photochemical formation of hydroxamic acids from nitronate anions.
Reactivities of Stable Rotamers. VIII. Difference in Reactivities of 1,2,3,4-Tetrachloro-9-(2-halo-1,1-dimethylethyl)triptycene Rotamers in Lewis Acid-catalyzed Reactions
Authors: Kikuchi Hiromi , Seki Shigetaka , Yamamoto Gaku , Mitsuhashi Tsutomu , Nakamura Nobuo , Oki Michinori
Published: July 2006

±sc-1,2,3,4-Tetrachloro-9-(2-chloro-1,1-dimethylethyl)triptycene was found to react in the presence of titanium(IV) chloride at room temperature to give an isomeric mixture of 1,2-dimethyl-7,8,9,10-tetrachloro-1,2,6,10b-tetrahydro-6,10b-o-benzenoaceanthrylenes. The structure of the latter was confirmed by independent syntheses. In contrast, the ap conformer of the former did not give any sign of the reaction under the same conditions but reacted when antimony(V) chloride was added to give the same mixture. Careful examination of the reaction mixture suggests that the starting material was rapidly converted to (E)-1,2,3,4-tetrachloro-9-(1-methyl-1-propenyl)triptycene and cyclization followed. Action of silver nitrate on ±sc-9-(2-bromo-1,1-dimethylethyl)-1,2,3,4-tetrachlorotriptycene afforded a mixture of the stereoisomers of the olefin while the ap form remained intact.
Reactivities of Stable Rotamers. IX. Ionizing Reactions of 9-(2-Bromomethyl-6-methylphenyl)fluorene Rotamers
Authors: Murata Shigeru , Kanno Seiichiro , Tanabe Yo , Nakamura Mikio , Oki Michinori
Published: July 2006

Ionizing reactions of ap-9-(2-bromomethyl-6-methylphenyl)fluorene in ionizing solvents afforded 12-methyl-8,12b-dihydrobenz[a]aceanthrylene and its dehydrogenated compound, whereas the sp isomer remained intact. Forced ionization of the sp isomer with silver salts afforded products originated from the corresponding cation and either the anion of the salt or the solvent, whereas the ap isomer gave cyclized product under the same conditions, if the nucleophilicity of the solvent was poor. The reaction of the sp isomer was faster than the ap in nucleophilic solvents, whereas the reverse was true for poorly nucleophilic solvents. Solvolysis of the rotamers in formic acid yielded the corresponding formates, the sp isomer reacting faster than the ap. The results are discussed on the basis that the solvation shell in the ap form is completed by the participation of the fluorene ring whereas in the sp form the shell is completed by the solvent molecules.
Oxidation of Lipids. I. Quantitative Determination of the Oxidation of Methyl Linoleate and Methyl Linolenate
Authors: Yamamoto Yorihiro , Niki Etsuo , Kamiya Yoshio
Published: July 2006

The extent of oxidation of methyl linoleate and methyl linolenate has been measured quantitatively by several methods such as oxygen uptake, substrate disappearance, and formation of conjugated diene, TBA-reactive material and of hydrocarbon gas. In the early stage of oxidation of methyl linoleate, oxygen uptake, substrate disappearance, peroxide and conjugated diene formation were all quantitative and their results agreed well each other. Little TBA-reactive material and hydrocarbons were observed. In the oxidation of methyl linolenate, however, no product was formed quantitatively, and the extent of oxidation estimated decreased in the order, oxygen uptake>substrate disappearance>peroxide>conjugated diene>TBA-reactive material.
The Solvent Extration of Amino Acids with Crown Ether
Authors: Noguchi Hideyuki , Nakamura Hiroyoshi , Nagamatsu Masatoshi , Yoshio Masaki
Published: July 2006

Protonated amino acids were extracted with crown ether and Metanil Yellow anion into 1,2-dichloroethane. The overall extraction constants (Kex) for the 1:1:1 complex, AHLIn, of 18-crown-6 (L) with protonated amino acid (AH+), and the Metanil Yellow anion (In−) between 1,2-dichloroethane and water have been determined at 25.0 °C. The values of the extraction constants (logKex) were found to be 5.2, 6.2, 6.4, 6.3, 5.5, 6.2, and 5.5 for l-α-alanine, l-valine, l-leucine, l-phenylalanine, β-alanine, l-lysine, and aspartic acid respectively at 25.0 °C. The dependence of the varieties of crown ether on the extractability of l-leucine has been investigated. The highest extractability was obtained when water-soluble crown ether was used.
Optical Resolution of 2-Amino-1,2-diphenylethanol by Preferential Crystallization and Its Utilization in Fractional Crystallization and Enantioselective Reduction of Prochiral Ketones
Authors: Saigo Kazuhiko , Ogawa Shigeo , Kikuchi Shigetoshi , Kasahara Atsushi , Nohira Hiroyuki
Published: July 2006

(±)-erythro-2-Amino-1,2-diphenylethanol prepared from benzoin oxime by catalytic reduction was successfully resolved into a pair of optically active forms by preferential crystallization. The optically active amino alcohol was found to be useful as a basic resolving agent for the optical resolution of tartaric acid, trans-2,3-oxiranedicarboxylic acid, 2-hydroxy-2-phenylpropionic acid, and 3-endo-benzamido-5-norbornene-2-endo-carboxylic acid. Chiral hydrides prepared from lithium aluminium hydride and optically active threo- or erythro-2-amino-1,2-diphenylethanol derivatives were applied to the enantioface differentiating reduction of prochiral ketones to give the corresponding optically active alcohols in 26–72% optical purities.
Synthetic Approach toward Antibiotic Tunicamycins. 3. Methyl 3,4,7,8-Tetra-O-acetyl-10-O-benzyl-2-benzyloxycarbonylamino-2,6-dideoxy-11,12-O-isopropylidene-β-l-dodecodialdo-(12R)-furanose-(12,9)-pyranosides-(1,5)
Authors: Fukuda Yoshimasa , Sasai Hiroaki , Suami Tetsuo
Published: July 2006

Higher carbon carbohydrates, dodecose derivatives have been synthesized by the base-catalyzed addition of nitro sugar to sugar aldehyde. The addition reaction of methyl 2-benzyloxycarbonylamino-2,6,7-trideoxy-3,4-O-isopropylidene-7-nitro-α-d-galacto-heptopyranoside to 3-O-benzyl-1,2-O-isopropylidene-α-d-ribodialdofuranose-(1,4) yielded nitro-dodecose derivatives. The nitro-dodecose derivatives were then converted into the corresponding hydroxy and acetoxy derivatives.
The Crystal Structure of o-Fluorobenzamide
Authors: Kato Yoshihiro , Sakurai Kiichi
Published: July 2006

The crystal of the title compound is monoclinic, with space group P21/a, a=12.695, b=20.534, c=5.133 Å, β=97.80°, Z=8. The molecules are connected by one pair of hydrogen bonds to form asymmetric dimers and these dimers are further linked by two kinds of hydrogen bonds into endless chains along the c axis.
Anomalous Crystallization Behavior in the Glass Forming Composition Region of the H2O–HNO3 System
Authors: Satoh Kenji , Kanno Hitoshi
Published: July 2006

Glass formation composition region of aqueous HNO3 solution is determined. Anomalous crystallization behavior was observed for the solution having the composition near HNO3·3H2O. From Tg data, Tg for a bulk glassy water is estimated to be −144±2 °C.
The Effect of Ultraviolet Radiation on Wettability of Polymer Surfaces
Authors: Esumi Kunio , Meguro Kenjiro , Schwartz A M , Zettlemoyer A C
Published: July 2006

The wettability of polystyrene and poly(methyl vinyl ketone) surface can be markedly changed by ultraviolet irradiation in air. The contact angle of water on both polymers decreases dramatically as a function of exposure time. This effect is mainly due to increase in the polar component of surface energy. The wettability of irradiated polymers goes back to near original values due to soluble photooxidation products into water after the water extraction.
A Mild Silver Salt-induced Oxidation of Dibromo-5-hydroxytropolones to Dibromo-p-tropoquinones
Authors: Takeshita Hitoshi , Kusaba Tomoyuki , Mori Akira
Published: July 2006

The treatment of 3,6-dibromo-, 3,7-dibromo, 4,6-dibromo-, and unsubstituted 5-hydroxytropolones with silver acetate in acetone gave the corresponding p-tropoquinones in good yields. When this reaction was carried out in protic solvents, some of these tropoquinones underwent further attack by solvent nucleophiles to give Michael-adducts or ring-contracted cyclohexadienones.
A Facile One-pot Synthesis of N-Substituted Phthalimides Using a Catalytic Amount of Crown Ether
Authors: Soai Kenso , Ookawa Atsuhiro , Kato Kyoko
Published: July 2006

N-Substituted phthalimides, intermediates of the Gabriel synthesis, were obtained in high yields (84–100%) by the addition of a catalytic amount of 18-crown-6 to the reaction of potassium phthalimide and alkyl halides in toluene.
Atropisomerism in Metal Chelates. The Crystal Structure and Absolute Configuration of (−)589-3-(2,4-Dinitro-1-naphthyl)-2,4-pentanedionato[tris(2-aminoethyl)amine]cobalt(III) Dibromide
Authors: Nakano Yoshiharu , Sato Shoichi
Published: July 2006

The crystal structure and the absolute configuration of (−)589-3-(2,4-dinitro-1-naphthyl)-2,4-pentanedionato[tris(2-aminoethyl)amine]cobalt(III) dibromide were determined by X-ray diffraction. The complex crystallizes as the orthorhombic space group P212121, with a=13.738(2), b=15.446(1), c=12.243(1) Å, and Z=4. The structure was solved by the Patterson-Fourier method and refined to a final R1 value of 0.038 for the 3347 observed reflections with |Fo|>3σ(|Fo|). The acetylacetonate (acac) ring adopts a more deformed boat conformation than that in 3-(6-methyl-2,4-dinitrophenyl)-2,4-pentanedionato analogue. The three chelate rings of tris(2-aminoethyl)amine (tren) have envelope conformations and adopt λ, λ, and δ conformations. The absolute configuration of the title compound can be designated as R.
Photoelectrochemical Studies of MoS2 Electrode by Rotating Ring-disk Electrode Technique
Authors: Fujishima Akira , Noguchi Yoshikazu , Honda Kenichi , Loo Boon H
Published: July 2006

Photoelectrochemical processes at both n- and p-type MoS2 electrodes were studied by rotating ring-disk electrode technique. In comparison with other semiconductor photoelectrodes such as CdS, ZnO, and TiO2, the competitive oxidations of various reducing agents at n-MoS2 electrode were not clearly dependent on their redox potentials. The MoS2 photoanode was particularly stabilized in I− solutions, and this was attributed to the specific adsorption of I− ions on the electrode surface. Two step waves were observed in the photocurrent-potential curves of MoS2 photoanode in I− solutions. The first wave was controlled by the diffusion of I− ions from the bulk solution to the electrode surface, and the second wave at more anodic potential was dependent on the formation of the photogenerated holes.
Conformational Analysis of Stilbenes by Photoelectron Spectroscopy
Authors: Kobayashi Tsunetoshi , Suzuki Hiroshi , Ogawa Keiichiro
Published: July 2006

Conformations of (Z)-stilbene, (E)-stilbene, and various methyl-substituted (E)-stilbenes were discussed from the standpoint of photoelectron spectroscopy. Photoelectron spectral data of (Z)-stilbene and (E)-stilbene were found to be perfectly consistent with the results by the gas electron diffraction method concerning the twist angles of the phenyl groups. The twist angles of the phenyl groups in various methyl-substituted (E)-stilbenes were estimated using the photoelectron spectral data by the new method presented recently. These estimated values correspond well to those obtained from the standpoint absorption spectra.
Translational Energy Distribution and Relative Emission Cross Section of Excited Hydrogen Atom Produced in Electron-chloroform Collisions
Authors: Ogawa Teiichiro , Miyoshi Fumihiro , Higo Morihide
Published: July 2006

Dissociative excitation of CHCl3 and CDCl3 has been investigated by means of the controlled electron impact and the high resolution emission spectroscopy. The emission spectrum shows such excited species as H, CH, CH+, Cl+, CCl, and HCl+. The excitation function of H* has two thresholds, 20.5 and 41.0 eV. The emission cross spections of H* and D* reveal an isotope effect, which is dependent on the excitation energy and the principal quantum number. Translational energy distributions of H* and D* have been determined from the Doppler line shape of the Balmer-β line, and average translational energies from the half-width of the Balmer-α, β, γ, and δ lines. There are no noticeable isotope effect for the translational energy; their major peaks lie at 0–1, 4, and 6–12 eV. These findings indicate that there are at least three major processes for the formation of the excited hydrogen atom. They are assigned to dissociative excitation through the Rydberg states converging to the (2a1)1 ionic states and through excited Rydberg states.
A Co-59 Nuclear Magnetic Resonance Study of the Interaction of Lanthanoid Shift Reagents with Tris(β-diketonato)cobalt(III) Complexes
Authors: Hirayama Masatoshi , Kawamata Yoshimichi , Fujii Yuki , Nakano Yoshiharu
Published: July 2006

Ln(fod)3 (Ln=La, Pr, Nd, Sm, and Eu)-induced 59Co shifts (δCo) for a series of tris(β-diketonato)Co(III) complexes were determined directly from separate observations of the free complexes and 1 : 1 adducts with Ln(fod)3 at room temperature (25 °C) in CHCl3; Ln(dpm)3-induced shifts were also observed in CCl4. Values of δCo corrected for the adduct-formation shifts (δ′Co) are separated into contact and pseudo-contact contributions by using the intercept and slope in a linear plot of δ′Co⁄ vs.  D⁄. It is suggested from the estimated hfs constant of 59Co (≈−0.2 G, 10−4T) that the spin polarization mechanism may be predominant for the electron spin transfer from Ln ion into Co ion.
X-Ray Structures of (−)589-Bis(isothiocyanato)bis(1,3-propanediamine)chromium(III) Bis[μ-(+)-tartrato(4−)]bis[antimonate(III)] Dihydrate and Its Cobalt(III) Analogue
Authors: Matsumoto Keiji , Ooi Shun’ichiro , Kawaguchi Hiroshi , Nakano Mamoru , Kawaguchi Shinichi
Published: July 2006

The crystal structures of (−)589-[Cr(NCS)2(tn)2]1/2[Sb2(+)-tart2]·2H2O (1) and (−)589-[Co(NCS)2(tn)2]1/2-[Sb2(+)-tart2]·2H2O (2) have been determined from the X-ray diffraction data. The structures were solved by the Patterson-Fourier method and refined by the least-squares method to R=0.043 (1) and 0.070 (2) for 2659 and 1826 reflections respectively. The two crystals are isomorphous with each other. The complex cations in 1 and 2 have a similar geometry. Their absolute configuration is Λ, and agrees with that assigned from the CD spectra in comparison with those in the first d-d band region of bis(ethylenediamine)cobalt(III) complexes. The six-membered chelate rings are of chair conformation. The chairs are flattened more than expected from the conformational analysis.
Photochemical Electron Transport from Water Layer to Organic Layer via Sodium Anthraquinone-2-sulfonate by Stepwise Two Photon Excitation
Authors: Inoue Haruo , Hida Mitsuhiko
Published: July 2006

Photochemical electron transport from hydroxide ion to organic acceptor molecule via an anthraquinone derivative as an electron carrier was investigated in homogeneous, cationic micellar, and cationic reversed micellar systems. In homogeneous alkaline aqueous ethanol, the photochemically generated radical anion of sodium anthraquinone-2-sulfonate (1) was stable against further irradiation with visible light (λ>450 nm), while the dianion of 1 was reversibly converted to the radical anion by visible light irradiation. The reversible conversion was accelerated by the addition of an organic acceptor molecule such as 1,4-dicyanobenzene. In a cationic hexa-decyltrimethylammonium micellar system, an effective photoreduction of 1 by an electron transfer from hydroxide ion concentrated on the micellar surface to the excited 1 located in the surface area of the micelle was observed. In a reversed micellar system an electron was effectively transported from the water layer to the organic layer; an electron was transfered from hydroxide ion in the water layer incorporated in a benzylhexadecyldimethylammonium reversed micelle to 1 at the micellar surface by irradiation with light of λ=365 nm. Successive visible light irradiation (λ>450 nm) caused an electron ejection from the radical anion of 1 to benzonitrile as a bulk phase solvent. The possibility of the incorporation of carbon dioxide into the acceptor cycle of the electron transport system was also examined. In pyridine solution, carbon dioxide caused the disappearance of the reduced species of 1 on visible light irradiation (λ>450 nm). Trace amounts of dihydropyridinedicarboxylic acid derivatives were obtained.
Thermochemical Hydrogen Production by the Magnesium-Sulfur-Iodine Cycle
Authors: Mizuta Susumu , Kumagai Toshiya
Published: July 2006

A new thermochemical cycle, consisting of (i) redox reaction of sulfur dioxide and iodine with magnesium oxide in aqueous phase, (ii) hydrolysis of magnesium iodide, (iii) thermal decomposition of magnesium sulfate, and (iv) thermal dissociation of hydrogen iodide, is presented for hydrogen production. The key reactions (i) and (ii) are experimentally verified.
Acylthiocyclopropenium Ions
Authors: Yoshida Hiroshi , Nakajima Mikito , Ogata Tsuyoshi , Matsumoto Kiyoshi
Published: July 2006

On treatment with a mixture of thiocarboxylic acid and perchloric acid in acetic anhydride, cyclopropenone gave acylthiocyclopropenium perchlorate in a good yield. Bis(acylthio)cyclopropene also yielded the salt under similar reaction conditions. The salt was stable under nitrogen at low temperatures, but was easily hydrolyzed to yield the corresponding cyclopropenethione.
Synthesis and Alkali-cation Complexing Properties of 12-Crown-4 Derivatives
Authors: Miyazaki Takeshi , Yanagida Shozo , Itoh Akira , Okahara Mitsuo
Published: July 2006

Benzyloxymethyl-12-crown-4, a precursor of hydroxymethyl-12-crown-4, is prepared in an excellent yield by the reaction of 3-benzyloxy-1,2-propanediol with 1,8-dichloro-3,6-dioxaoctane in the heterogeneous t-BuOLi/t-BuOH/LiBr·2H2O reaction system. The hydrogenolysis in the presence of p-toluenesulfonic acid leads to a good yield of hydroxymethyl-12-crown-4. The sandwich-type 2:1 complexation with Na+ of 12-crown-4 and hydroxymethyl-12-crown-4 derivatives was discussed on the basis of the stability constants and the solvent extraction in the CH2Cl2–water system.
Photoreduction of Silver Ion in a Titanium Dioxide Suspension
Authors: Hada Hiroshi , Yonezawa Yoshiro , Saikawa Masahiko
Published: July 2006

Quantum yields ranging from 0.084 to 0.191 were obtained for the reduction of Ag+ by irradiation of light at 365 nm on a TiO2 surface in aqueous solutions containing 1×10−4 to 1×10−2 mol dm−3 AgClO4. Some features of the reduction were preliminarily examined with the aid of an electrochemical measurement of TiO2 sinter. It is proposed that some conduction-band electrons, produced in the TiO2 by irradiation, transfer to Ag+ adsorbed on the TiO2 surface and that positive holes react with water molecules. The photoreduction of Ag+ is optically sensitized by addition of Uranine. The apparent quantum yield (the number of reacted ions/the number of photons incident to the suspension) of the dye-sensitized photoreduction of Ag+ is 0.01.
Fourier Transform Infrared Photoacoustic Spectroscopy of Polymers
Authors: Teramae Norio , Hiroguchi Masayuki , Tanaka Shigeyuki
Published: July 2006

Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) was applied to the structural elucidation of several kinds of organic polymers. By using a photoacoustic detection, infrared spectra of textile fabrics and rubbers containing carbon black could be measured without destructive and troublesome sample preparations. Curing process of resol type phenolic resins was examined by FTIR-PAS and conventional KBr disk method. FTIR-PAS was found to be sensitive to the structural change of the surface of the cured resins. Helmholtz resonance effect of the photoacoustic cell and the effect of the thermal properties of samples in FTIR-PAS were also discussed.
The Crystal Structure of Na2H2[Co4I3O18(OH2)6][Co4I3O16(OH)2(OH2)6]·22H2O
Authors: Kondo Hidetaka , Kobayashi Akiko , Sasaki Yukiyoshi
Published: July 2006

The title compound has the analytical formula of Co4H36I3NaO35 and is seemingly well formulated as NaH2[Co4I3O18(OH2)6]·11H2O. But the structure determination revealed that the crystals contain non-protonated [Co4I3O18(OH2)6]3− and doubly protonated [Co4I3O16(OH)2(OH2)6]−. The anion itself has a new variation of the Anderson structure. The almost identical three pK’s of the acid, H3[Co4I3O18(OH2)6], explain the formation of the present crystals by co-precipitation of two forms of the anion with different degrees of protonation. Crystals are monoclinic, space group P2/c, with a=15.172(2), b=10.874(1), c=19.436(3) Å, β=116.58(1)°, U=2867.6(5) Å3, and Z=2. The final R factor was 0.036 for 7010 independent reflections.
Dehydrooligopeptides. III. Synthesis of (Z,Z)- and (Z,E)-Geometric Isomers of Dehydrodipeptides and Their Base-catalyzed Transformation to the Hydantoin Derivatives
Authors: Shin Chung-gi , Yonezawa Yasuchika , Yamada Toyofumi , Yoshimura Juji
Published: July 2006

N-Benzyloxycarbonyl (Cbz)-(Z,E)-dehydrodipeptides, comprised of both (Z)- and (E)-α-dehydroamino acid residues, were first synthesized by dehydrochlorination of Cbz-(Z)-dehydrodipeptides containing an erythro-3-chloro-2-aminobutanoate moiety. Base-catalyzed transformation of the individual Cbz-(Z, Z)- and (Z, E)-dehydrodipeptides was carried out to give the corresponding new hydantoin derivatives. The NMR spectroscopic differences between the geometric isomers of both dehydrodipeptides and their hydantoin derivatives were elucidated.
Rapid Peptide Synthesis in Liquid Phase. Preparation of Angiotensin II and Delta-sleep-inducing Peptide by the “Hold-in-Solution” Method
Authors: Nozaki Sukekatsu , Muramatsu Ichiro
Published: July 2006

A new technique for rapid peptide synthesis has been demonstrated by the preparation of a protected angiotensin II, Z–Asp(OBzl)–Arg(NO2)–Val–Tyr(Bzl)–Ile–His(Bzl)–Pro–Phe–OBzl (1), and a protected delta-sleep-inducing peptide, Z–Trp–Ala–Gly–Gly–Asp(OBzl)–Ala–Ser(Bzl)–Gly–Glu(OBzl)–OBzl (2). Elongation of the peptide chain was carried out in 1,2-dichloroethane by repeating the following series of operations: acylation of a benzyl ester of amino acid or peptide with Boc-amino acid by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride and 1-hydroxybenzotriazole; washing of the organic layer; acidolysis of the α-amino protector; neutralization; and washing. Throughout the synthesis, the growing pep tides were held in the organic layer without being isolated. The protected peptides, 1 and 2, were obtained in overall yields of 78% and 53% based on their C-terminal amino acid esters, and were then hydrogenated to give angiotensin II and delta-sleep-inducing peptide, respectively, thus demonstrating the usefulness of this method for rapid peptide synthesis.
Nucleophilic Reaction upon Electron-deficient Pyridone Derivatives. IV. Ring Transformation of 1-Substituted 3,5-Dinitro-2-pyridones with Ketones in the Presence of Amines
Authors: Matsumura Eizo , Tohda Yasuo , Ariga Masahiro
Published: July 2006

Ring transformation of 1-substituted 3,5-dinitro-2-pyridones with 1,3-disubstituted acetones in the presence of secondary or primary amines gave p-nitroaniline derivatives and N-substituted 2-nitroacetamide. Two types of enamine intermediates, 2-azabicyclo[3.3.1]nonene derivatives and N-substituted 2-(5-amino-2-nitro-2,4-cyclo-hexadienyl)-2-nitroacetamides were isolated and characterized. The course of the base-catalyzed reaction is interpreted.
Studies on 2-Methyl- and 2-Phenyl-4-arylmethylene-2-imidazolin-5-ones and Related Compounds
Authors: Badr Mahmoud Zarif , El-Sherief Hassan Ahmed Hassan , Tadros Magda Ebeid
Published: July 2006

Compounds 4-arylmethylene-2-methyl-2-oxazolin-5-ones and 4-arylmethylene-2-styryl-2-oxazolin-5-ones react with primary aromatic amines in the presence of anhydrous zinc chloride to give the corresponding 4-arylmethylene-2-methyl-2-imidazolin-5-ones and 4-arylmethylene-2-styryl-2-imidazolin-5-ones (5) respectively. Treatment of 5 with phosphorus pentasulfide gives the corresponding 2-imidazoline-5-thiones. Reaction of 4-arylmethylene-2-phenyl-2-oxazolin-5-ones with hydroxylamine hydrochloride gives the corresponding imidazolinones which was reacted with alkyl halides and acid chlorides to give the corresponding ethers and esters respectively. Structures of the resulting products have been characterized on the basis of elemental analysis, IR, and UV data.
Translational Energy Distribution of the Excited Hydrogen Atom (n=3) Obtained by Controlled Electron Impact on CH4
Authors: Ogawa Teiichiro , Kurawaki Junichi
Published: July 2006

Dissociative excitation of CH4 has been investigated through the analysis of the high resolution spectra of the Balmer-α line. Translational energy distribution of H*(n=3) obtained in e-CH4 collisions has three distinct components and another indefinite component; their peaks lie at 3, 0–1 and 4, and 8–12 eV, respectively.
A Convenient Method for the Preparation of S-Esters of Thio Analogs of Malonic Acid
Authors: Imamoto Tsuneo , Kodera Masahito , Yokoyama Masataka
Published: July 2006

2-Carboxyethanethioic S-esters(RSCOCH2COOH) and propanebis(thioic) S,S′-diesters (RSCOCH2COSR) were easily prepared in high yields by the direct condensation of malonic acid with thiols in the presence of ethyl polyphosphate (PPE).
Preparations and Characterization of Some Carbonyl(1-cyanoethyl)ruthenium(II) Complexes
Authors: Hiraki Katsuma , Ochi Naoyuki , Kitamura Tsuneyuki , Sasada Yoko , Shinoda Sumio
Published: July 2006

A hydridoruthenium(II) complex [RuClH(CO)(PPh3)3] reacted easily with acrylonitrile and fumaronitrile to give chloro-bridged binuclear (1-cyanoethyl)ruthenium(II) complexes, [{Ru(MeCHCN)Cl(CO)(PPh3)2}2] (2) and [{Ru(NCCH2CHCN)Cl(CO)(PPh3)2}2], respectively. Complex 2 reacted with 4-picoline (pic), Na[BHPz3] (Pz=1-pyrazolyl), Na[BPz4], and Na[Et2NCS2]·3H2O to afford the corresponding (1-cyanoethyl)ruthenium(II) complexes, [{Ru(MeCHCN)Cl(CO)(pic)(PPh3)}2] (3), [Ru(MeCHCN)(BHPz3)(CO)(PPh3)] (accompanied by a small amount of [Ru2(MeCHCN)2Cl(BHPz3)(CO)2(PPh3)4]), [Ru2(MeCHCN)2Cl(BPz4)(CO)2(PPh3)2], and Na[Ru(MeCHCN)Cl(Et2NCS2)(CO)(PPh3)], respectively. Complex 3 reacted with thallium(I) acetylacetonate [Tl(acac)], resulting in the formation of [{Ru(MeCHCN)(acac)(CO)(PPh3)}2] and [Ru(MeCHCN)(acac)(CO)(pic)(PPh3)]. These new complexes were characterized by means of elemental analysis and spectroscopic data. The diastereoisomerism was also discussed as regards these (1-cyanoethyl)ruthenium(II) complexes.
Non–covalent Interactions in Metal Complexes. V. Stereoselectivity in Cobalt(III) Mixed-chelates with a Salen-like Schiff Base and 1-l-Menthyloxy-3-benzoylacetone
Authors: Nakamura Michio , Okawa Hisashi , Inazu Takahiko , Kida Sigeo
Published: July 2006

Cobalt(III) mixed-chelates, Co(SB)(l-moba), containing a salen-type Schiff base (SB) and 1-l-menthyloxy-3-benzoylacetone (H(l-moba)) have been synthesized, where H2salen stands for N,N′-disalicylideneethylenediamine. These complexes were shown to have a cis-β-octahedral structure, based on electronic and infrared spectra. They showed circular dichroism in the visible region, demonstrating an induction of an asymmetry around the metal ion. On the basis of NMR and CD spectra and in comparison with the CD spectrum of Λ-Co(sal-(S, S)-ch)(bazc), it was shown that the Co(SB) (l-moba) complexes prefer the Λ-cis-β1-configuration. The reaction of racemic N,N′-disalicylidene-trans-1,2-cyclohexanediaminatocobalt(II) (Co(salch)) and racemic N,N′-disalicylidene-1,2-propanediaminatocobalt(II) (Co(salpn)) with H(l-moba) in a 2 : 1 mole ratio yielded Λ-cis-β1-Co(sal-(S, S)-ch)(l-moba) and Λ-cis-β1-Co(sal-(R)-pn)(l-moba), respectively, as amain species. The stereoselectivity in the present complexes has been discussed in terms of the inter-ligand, hydrophobic CH/π-interaction which may occur between the l-menthyl group and an aromatic ring of the Schiff bases.
Synthesis and Characterization of Copper(II) and Nikel(II) Complexes of 1,5-Diamino-3-pentanol and Its Derivatives
Authors: Murase Ichiro , Hatano Masao , Tanaka Masahiko , Ueno Shigehiro , Okawa Hisashi , Kida Sigeo
Published: July 2006

Dihydrochloride of a binucleating ligand, 1,5-diamino-3-pentanol (Hdpl·2HCl) has been synthesized by a new method in a high yield (>70%). This ligand forms 1 : 1 complexes with copper(II), Cu(dpl)X(X=BF4, ClO4, NO3, and Cl(H2O)). The cryomagnetic study of the copper complexes has shown that they are binuclear, and a strong antiferromagnetic interaction is operating between two copper ions. The binuclear structure seems to be quite stable even in aqueous solution. The 1 : 1 complex with nickel(II) was also isolated as tetraphenylborate, which was essentially diamagnetic. A planar binuclear structure similar to the copper complexes was assumed for this complex. Its absorption band at 29.8×103 cm−1 (ε=160) was attributed to the charge transfer transition from the bridging oxygen to the nickel similarly to the bands in the 25–29×103 cm−1 region usually observed for alkoxo-oxygen bridged binuclear copper(II) complexes. Some 2 : 1 copper(II)–dpl complexes have also been synthesized and characterized as binuclear complexes. 1,5-Bis(dimethylamino)-3-pentanol has been synthesized, and its 2 : 1 copper(II) complexes have been isolated.