bluuebunny/crossref_metadata_2025 huggingface dataset:
X-Ray Fluorescence Spectroscopy of Inorganic Solids. III. Si Kα and Kβ Spectra in Binary Silicates
Authors: Kikuchi Niro , Maekawa Takashi , Yokokawa Toshio
Published: July 2006

The Si Kα and Kβ spectra of several silicates were measured. The Kα spectra showed negative energy shifts referred to SiO2; these are consistent with the results for the binary silicate glasses. On the other hand, the Kβ shifts were positive and the absolute values were about ten times as large as the Kα shifts in each compound. A linear relation was observed between Kα and Kβ energy shifts. The Si 1s energy shift for the orthosilicate was estimated from the Kβ spectral splitting of Na2Si2O5. The stability of the silicon–oxygen bond was discussed with the aid of the shifts in Kβ and the Si 1s. The above linear relation suggests that the silicon–oxygen bond strength is lowered (the Kβ energy is increased) with decreasing Goulombic interaction (lowering Kα energy) between silicon and oxygen in the silicates.
Synthetic Studies of Laurencin and Related Compounds. IV. Synthesis of cis-2-Ethyl-8-formyl-3,4,7,8-dihydro-2H-oxocin-3-one 3-Ethylene Acetal and Related Compounds
Authors: Masamune Tadashi , Matsue Hajime , Murase Hisashi
Published: July 2006

The synthesis of cis-2-ethyl-8-formyl-3,4,7,8-dihydro-2H-oxocin-3-one and its derivatives, key intermediates for synthesis of laurencin, from methyl 2-ethyl-2,5-dihydro-2-furoates is described. The structure and configuration of these compounds and the synthetic intermediates are defined clearly on the basis of the chemical and spectral evidence.
Preparation and Circular Dichroism of Dichloro-(S)-2-(butylphenylphosphinomethyl)pyrrolidine-palladium(II)([PdCl2L]) and Its Related Complexes, and the Absolute Configuration of [PdCl2L] Determined by X-Ray Analysis
Authors: Kinoshita Isamu , Kashiwabara Kazuo , Fujita Junnosuke , Yamane Takashi , Ukai Hitoshi , Ashida Tamaichi
Published: July 2006

(S)-2-(Butylphenylphosphinomethyl)pyrrolidine(L) was prepared from (S)-proline via four main reaction steps. A pair of diastereomers of the PdCl2L complex, the isomerism of which comes from chiral configuration of the phosphorus atom, crystallized in different forms (needle and block), which were separated by hand picking. The molecular structure and absolute configuration of one(block) of the dichloro complexes was determined by X-ray analysis. Crystallographic data are: P212121, Z=4, a=13.576(4), b=16.351(3), c=8.041(2) Å, and R=7.8% for 1659 reflections. The Pd atom has a distorted square planar coordination of four donor atoms. The Pd-Cl bond distance trans to Pd-P, 2.367 Å, is longer than that trans to Pd–N, 2.296 Å. The absolute configuration of the coordinated phosphorus atom was determined to be R by assuming S configuration for the asymmetric carbon atom of the aminophosphine. The corresponding diastereomers of the dibromo complex were also prepared from each diastereomer of the chloro complex. The circular dichroism spectra of these diastereomers were compared with one another and with those of other related complexes, and the vicinal effects due to the chiral phosphorus atoms in these complexes were examined.
Phosphinyl- and Phosphinothioylamino Acids and Peptides. IV. Further Examples of Use of the Diphenylphosphinothioyl Group for the Protection of Amino Acids
Authors: Ikeda Shigeru , Tonegawa Fumio , Shikano Etsuro , Shinozaki Kozo , Ueki Masaaki
Published: July 2006

The preparation and purification of diphenylphosphinothioyl(Ppt)-amino acids were studied. The side-chain functional groups of tyrosine and cysteine were found to react also with diphenylphosphinothioyl chloride to form O-Ppt and S-Ppt derivatives. Acidic reagents for the removal of N-Ppt group were examined by using N,O-bis-Ppt-tyrosine ethyl ester (III) as the most difficult model, HCl in HCO2H–CH2Cl2 being found to be most preferable. The O- and S-Ppt bonds were stable during the course of acidic treatments, but could be removed by alkaline hydrolysis. An application of Ppt-amino acids to the solid phase peptide synthesis is given.
Synthesis of 3-Ethoxycarbonyl-1,2,3,4,5,10-hexahydroindeno[1,2-d]azepine
Authors: Kimura Masaru , Morosawa Shiro
Published: July 2006

3-Ethoxycarbonyl-1,2,3,4,5,10-hexahydroindeno[1,2-d]azepine (10b) was synthesized from 1-benzylpiperidin-4-one and 1-benzyl-4-[o-(hydroxymethyl)phenyl]hexahydroazepin-4-ol. Compound 10b is of particular interest as an intermediate for the preparation of the hitherto unknown indeno[1,2-d]azepine. It was found that 1-ethoxycarbonyl-4-[o-(hydroxymethyl)phenyl]hexahydroazepin-4-ol and 1-ethoxycarbonyl-4-[o-(hydroxymethyl)phenyl]piperidin-4-ol (16b) give 1-ethoxycarbonylspiro[azepin-4,1′(3H)-isobenzofuran] and 1-ethoxycarbonylspiro[3H-isobenzofuran-1,4′-piperidine] (17b), respectively. Treatment of 16b with 88% formic acid gave 17b and 2-ethoxycarbonyl-2,3,4,9-tetrahydro-1H-indeno[2,1-c]pyridine.
The Nature of Athabasca Tar Sand (Canada) and Tar Sand Derivatives. A Comparison with Coal-hydrogenolysis Products
Authors: Yoshida Ryoichi , Yoshida Tadashi , Ikawa Yasuko , Okutani Takeshi , Hirama Yasuko , Nakata Yoshinori , Yokoyama Shinichi , Makabe Masataka , Hasegawa Yoshihisa
Published: July 2006

Solvent extracts of Athabasca tar sand were analyzed by the Brown-Ladner method, the Takeya et al. method, and the Speight method on the basis of the 1H-NMR data and by 13C-NMR spectroscopy. The structural characteristics of Athabasca tar sand derivatives were also compared with those of coal-hydrogenolysis products. The results show that the structural characteristics of hexane solubles, monomers consisting of one aromatic ring substituted highly with C6 aliphatic chains, resemble those of the oil fraction produced during the initial stage of the hydrogenolysis of Taiheiyo coal. However, the structural characteristics of the hexane insoluble-benzene solubles, oligomers consisting of 2 aromatic rings substituted highly with C4–5 aliphatic chains, are different from those of any coal-hydrogenolysis products. In addition, the close agreement between the fa value obtained by the Brown-Ladner method and 13C-NMR may indicate that, for solvent extracts of Athabasca tar sand, the assumption in the Brown-Ladner method that the atomic H/C ratio of aliphatic structures is 2 is proper.
Stereochemical Studies of the Hydrogenation with Asymmetrically Modified Nickel Catalysts; The Hydrogenation of Methyl 2-Alkyl-3-oxobutyrate
Authors: Tai Akira , Watanabe Hiroshi , Harada Tadao
Published: July 2006

The hydrogenation of methyl 2-methyl-3-oxobutyrate (I) to methyl 3-hydroxy-2-methylbutyrate (III) was carried out with various types of asymmetrically modified nickel catalysts (MNi). The use of MNi always resulted in the deviation of the ratio, 2S/2R=((2S,3R)-III+(2S,3S)-III)/((2R,3R)-III+(2R,3S)-III, from 1/1, in spite of the use of racemic I. A catalyst giving a larger 2S/2R value always gave a larger 3R/3S value. These results led to the conclusion that the configurations at the C-2 and C-3 positions of the product were determined in the process of the formation of the complex between the substrate and the modifying reagent (the absorption step), not at the step of the hydrogen addition to the adsorbed substrate (the rate-determining step). The best optical yield and the highest ratio of erythro-III/threo-III were obtained when (R,R)-tartaric acid-MNi was used as a catalyst. The amounts of the isomers produced were in the following order: 2S,3R>>2R,3R≈2R,3S>2S,3S. Stereochemical models are proposed to account for the formation of the 2S,3R-isomer in a large excess.
Reaction of Coordinated Phosphines. IV. Mechanism of Carbon-Phosphorus Bond Cleavage in Triarylphosphines and Trialkylphosphines by Palladium(II) Acetate
Authors: Kikukawa Kiyoshi , Takagi Makoto , Matsuda Tsutomu
Published: July 2006

Reaction of triphenylphosphine with an equimolar amount of Pd(OAc)2 in acetic acid at room temperature in the presence of styrene gave trans-stilbene(94%), H3PO4(0.8%), PhP(O)(OH)2(40%), Ph2P(O)(OH)(19%), and Ph3P=O(35%). Reactions of tributyl- and trioctylphosphine with Pd(OAc)2 in acetic acid at 90 °C yielded butene(20%) and octene(1-; 22%, 2-; 17%), respectively, as main products. The phenylation of some olefins with triphenylphosphine in acetic acid-d, as well as other features of the reaction lead to the conclusion that nucleophilic attack on coordinated phosphorus atom is the most probable pathway for the formation of the phenylation agent (phenylpalladium species) in the reaction system among the others, ortho-metallation and oxidative addition.
Double Diels-Alder Reactions of Coumalic Acid with 1,3-Dienes
Authors: Imagawa Takeshi , Nakagawa Tsunefumi , Kawanisi Mituyosi , Sisido Keiiti
Published: July 2006

Thermal reaction of coumalic acid with 1,3-butadienes gave after diazomethane treatment dimethyl tricyclo[3.2.1.02,7]oct-3-ene-2,4-dicarboxylate via double Diels-Alder reaction. This represents the simplest synthesis of such a tricyclic system. The reaction with cyclopentadiene was also studied.
Studies on Chrysanthemate Derivatives. VI. A Stereoselective Synthesis of trans-3-(2,2-Dichlorovinyl)-2,2-dimethyl-1-cyclopropanecarboxylic Acid and Related Compounds
Authors: Nakada Yasuo , Endo Rokuro , Muramatsu Shigeki , Ide Junya , Yura Yasuo
Published: July 2006

A new method is described for the stereoselective synthesis of trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-1-cyclopropanecarboxylic acid (2t) via ethyl 3,3-dimethyl-4,6,6,6-tetrachlorohexanoate (3a) as a key intermediate. The key intermediate (3a) was obtained by addition of carbon tetrachloride to ethyl 3,3-dimethyl-4-pentenoate, prepared by condensation of 3-methyl-2-buten-1-ol and triethyl orthoacetate followed by Claisen rearrangement. Treatment of 3a with sodium t-pentyloxide in benzene gave ethyl trans-2,2-dimethyl-3-(2,2,2-trichloroethyl)-1-cyclopropanecarboxylate (6t) in good yield. Dehydrochlorination and hydrolysis of 6t using potassium hydroxide in ethanol afforded 2t in high yield.
Photochemical Reduction of Di-t-butyl Thioketone
Authors: Ohno Atsuyoshi , Uohama Misao , Nakamura Kaoru , Oka Shinzaburo
Published: July 2006

Photochemical reduction of the title compound has been studied and the result is compared with that from the reaction with thiobenzophenone, an aromatic thioketone.
Matrix Representation of an Olefinic Reference Structure for Monocyclic Conjugated Compounds
Authors: Aihara Jun-ichi
Published: July 2006

A reference polynomial which represents an olefinic reference structure of a monocyclic conjugated system can be expressed in the form of a Hermitian matrix. Some interesting features of the reference structure have been deduced from it.
1,3,5-Triarylpyrazoles as Phosphorescing Impurities in 1,3,5-Triaryl-2-prazolines
Authors: Yamamoto Hiroyoshi , Sano Yumiko , Shirota Yasuhiko , Seki Hajime , Mikawa Hiroshi
Published: July 2006

The origin of the phosphorescence observed for 1,3,5-triphenyl-2-pyrazoline and its substituted derivatives was investigated. Unlike the previously accepted conclusion, our conclusion is that the phosphorescence originates from the corresponding pyrazoles formed from the pyrazolines by the action of light.
Hydrogen Atom Abstraction of p-Chloranil Triplet in 1,4-Dioxane in the Presence and Absence of Tetrachlorohydroquinone
Authors: Kobashi Harumichi , Tomioka Yasunaka , Morita Toshifumi
Published: July 2006

Mechanisms of hydrogen atom abstraction by triplet p-chloranil [CA(T)] from 1,4-dioxane (DOH) and tetrachlorohydroquinone (CAH2) were studied in detail by means of nanosecond laser flash photolysis. A broad band around 740 nm in the transient absorption spectrum of CA in DOH was assigned to the charge-transfer band of the triplet EDA complex between CA and DOH. Efficiencies for the hydrogen atom abstraction from DOH and CAH2 were determined to be 0.13 and 0.58, respectively. The former value indicates that the hydrogen atom abstraction from DOH is less effective than a physical process in deactivation of the triplet complex. From the latter value together with the measured value of the quenching rate constant (1.7×109 dm3 mol−1 s−1) of the triplet by CAH2, it is inferred that the hydrogen atom abstraction of CA(T) from CAH2 takes place competing with an efficient radiationless deactivation via the triplet exciplex between CA(T) and CAH2 as a common intermediate.
Clustering Reactions of the Protonated Nitrogen N2H+ with Hydrogen Molecule in the Gas Phase
Authors: Hiraoka Kenzo
Published: July 2006

Clustering reactions of the protonated nitrogen N2H+ with hydrogen molecule, N2H+(H2)n−1+H2=N2H+(H2)n(n–1, n), were studied in a pulsed electron beam mass spectrometer with a high-pressure ion source. The values of enthalpy change −ΔSn−1,n(kcal/mol) and the entropy change −ΔSn−1,n(e.u.) obtained from the van’t Hoff plots of equilibrium constants were (0, 1) 7.2, 22.6, (1, 2) 1.5, 14.0. No cluster ions larger than N2H+(H2)2 were observed even at −187 °C. The relatively low values of enthalpy change for the clustering reactions (0, 1) and (1, 2) suggest that the positive charge in N2H+ is delocalized, the N2H+ ion very weakly interacting with additional hydrogen molecules electrophilicly. The calculated entropy change also suggests that hydrogen molecules in N2H+-(H2)n are weakly bound to the core ion N2H+, having considerable freedom of motion in the cluster ion. The thermochemical study proves that the cluster ion N2H+(H2)2 does not have the structure of the protonated hydrazine N2H6+.
The Electronic Spectra and Nonaqueous Oxidation and Reduction Potentials of Azoxybenzenes, and Their Mutual Correlation
Authors: Kubota Tanekazu , Miyazaki Hiroshi , Yamakawa Masumi , Ezumi Kiyoshi , Yamamoto Yoshiko
Published: July 2006

The near-ultraviolet absorption spectra of various p,p′- and m,m′-disubstituted azoxybenzenes were recorded in aprotic and protic solvents. The PPP-SCFMO-CI calculation was used in analyzing the spectra and the solvent effect on them. The π-π* bands of azoxybenzene could be well interpreted on the basis of the electronic structure of benzaldehyde N-phenyl oxime (a nitrone). In addition, the half-wave potentials of reduction (E1⁄2red) and oxidation (E1⁄2oxd) were also measured in nonaqueous solvents. These electrochemical data and the above spectral data satisfied a good linear relation: (E1⁄2oxd–E1⁄2red)=k1·Eho→luUV+k2, this equation having been previously proposed by us. In the Appendix, we have discussed the physical meaning of the constant term, k2, from the quantitative standpoint, using a series of alternant hydrocarbons as a typical example. Finally, a good linear relation between the E1⁄2red or E1⁄2oxd values and the substituent constants was demonstrated and discussed in azoxybenzenes.
Anharmonic Potential Functions of Simple Molecules. III. Computation of Vibration-Rotation Energies of XYZ and X2Y2 Type Linear Molecules through Direct Numerical Diagonalization: Application to the N2O Molecule
Authors: Suzuki Isao
Published: July 2006

A formalism has been developed for the calulation of vibration-rotation energy levels of linear XYZ and X2Y2 type molecules through direct numerical diagonalization of vibration hamiltonian matrix. The procedure of evaluating vibration as well as vibration-rotation energies can be described mostly in matrix algebra and thus easily converted to computer languages. The N2O molecule was chosen as an example of numerical treatment. Several approaches have been checked in evaluating Bv and Dv and they are discussed from the view point of accuracy and efficiency in computations. It is found that the variational approach of computing Bvr, contribution of rotational hamiltonian to Bv, is very efficient and accurate. Some peculiar features of the molecular potential of the X2Y2 type molecule are discussed in connection with their adaptation on the direct numerical diagonalization method.
Molecular Dynamics of the Inclusion Complexes of Cyclohexaamylose with Some Aromatic Amino Acids and Dipeptides
Authors: Inoue Yoshio , Katôno Yukio , Chûjô Riichirô
Published: July 2006

The molecular dynamics of the inclusion complexes of cyclohexaamylose as a model of enzyme have been studied by means of carbon-13 NMR spectroscopy. As substrates we have chosen l-phenylalanine, l-tyrosine, l-tryptophan, glycyl-l-phenylalanine, and l-phenylalanyl-l-lysine. The molecular motion of both the cyclohexaamylose and the substrates in D2O–DCl solutions have been investigated by dividing the spin-lattice relaxation time into two contributions, the overall molecular reorientation and the anisotropic internal rotation. Upon complex formation, the correlation times for the internal motion of the phenyl ring of phenylalanine residue increase by a factor of up to 8, while those for the overall reorientation increase by a factor of only 2. These results indicate that the complex formation of the substrate with the cyclohexaamylose are induced by the insertion of aromatic side chain into a cavity of cyclohexaamylose even in the aqueous solution. The overall correlation times of the substrates are about three to seven times snorter than those of the host molecule. Thus the forces which bind the host cyclohexaamylose and the substrate are relatively weak. It was observed that the tightness of the inclusion varies with the types of aromatic amino acids and dipeptides.
A Highly Stereospecific Isomerization of Oxiranes into Allylic Alcohols by Means of Organoaluminum Amides
Authors: Yasuda Arata , Yamamoto Hisashi , Nozaki Hitosi
Published: July 2006

Organoaluminum reagents of type R1R2NAlR2 allow highly stereospecific oxirane ring opening producing allylic alcohols under mild conditions. trans-Epoxycyclododecane is converted to (E)-2-cyclododecen-1-ol by reaction with diethylaluminum 2,2,6,6-tetramethylpiperidide (DATMP) in quantitative yield, while the cis-isomer gives only 8% yield of the same alcohol. Furthermore, this reagent enables us to perform the stereospecific isomerization of trisubstituted oxiranes: c-3-butyl-2-methyl-r-2-pentyloxirane is transformed into 2-pentyl-1-hepten-3-ol and the diastereomeric oxirane into (E)-6-methyl-6-undecen-5-ol, respectively. Such a rigorous stereospecificity is rationalized on the basis of a concerted syn elimination via the boat-like six membered ring imtermediary stage, in which the substituents of the oxirane ring should be arranged so as to minimize the severe nonbonded interactions.
Alkylation and Acylation of Active Methylene Compounds Using 1,8-Diazabicyclo[5.4.0]undec-7-ene as a Base
Authors: Ono Noboru , Yoshimura Tetsuji , Saito Tadashi , Tamura Rui , Tanikaga Rikuhei , Kaji Aritsune
Published: July 2006

Active methylene compounds are selectively monoalkylated with alkyl halides in benzene using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a base. Selectivity of monoalkylation decreases when the reaction is carried out in a polar solvent. Ethyl acetoacetate is O-acylated with acyl halides in the presence of DBU in acetonitrile to give the (E)-enol esters stereoselectively.
Temperature Effects on CD Spectra of β-Cyclodextrin Complexes with 2-Substituted Naphthalenes
Authors: Harata Kazuaki
Published: July 2006

CD spectra of β-cyclodextrin complexes with 2-naphthol, 2-naphthyloxyacetic acid, potassium 2-naphthoate, and potassium 2-naphthylacetate were measured at various concentrations of β-cyclodextrin and at temperatures ranging from 10 to 70°C. The temperature-dependent CD spectra of the 2-naphthyloxyacetic acid complex clearly show the 1 : 1 complex formation, but the other three complexes give CD intensity changes which are inexplicable in terms of the 1 : 1 stoichiometry. The molecular ellipticity and thermodynamic parameters were determined by the least-squares method. Enthalpy and entropy are in the ranges from −22.2 to −26.8 kJ·mol−1 and from −24 to −38 J·K−1·mol−1, respectively. They are strongly correlated to the volume of the substituent of the guest molecule, although the free energy is found in a quite narrow region (from −14.3 to −15.4 kJ·mol−1). The correlation is explained on the basis of the β-cyclodextrin-guest interaction and the solvation around the guest molecule.
A Simple Total Synthesis of (+)-Ferruginol, (+)-Sempervirol, and (+)-Podocarpa-8(14)-en-13-one
Authors: Matsumoto Takashi , Usui Shuji
Published: July 2006

The Wittig reaction of (R)-(−)-α-cyclocitral with (3-isopropyl-4-methoxybenzyl)-, (4-isopropyl-3-methoxybenzyl)-, and (3-methoxybenzyl) triphenylphosphonium chloride afforded the styryl derivatives which were partially hydrogenated to the corresponding dihydro derivatives (18, 26, and 27). Intramolecular cyclization of 18 and 26 with anhydrous aluminium chloride followed by demethylation with boron tribromide gave (+)-ferruginol and (+)-sempervirol. The similar cyclization of 27 gave (+)-13-methoxypodocarpa-8, 11, 13-triene. This was reduced with lithium in liquid ammonia in the presence of ethanol and then treated with dilute hydrochloric acid to give (+)-podocarpa-8(14)-en-13-one, a versatile intermediate for natural diterpene synthesis.
Radical-Ion Interaction. Diphenylmethyl and Triphenylmethyl Radicals Generated by the Dissociative Electron Attachment to Halogenated Compounds in Rigid Matrices
Authors: Izumida Tatsuo , Tanabe Yoshio , Ichikawa Tsuneki , Yoshida Hiroshi
Published: July 2006

Dissociative electron attachment to diphenylmethyl halides and triphenylmethyl halides in a γ-irradiated 3-methylhexane matrix at 77 K generates free radicals temporarily associated with a counterpart halide ion. The association is indicated by changes in the fluorescence and excitation spectra of the radicals as well as the charge-transfer excitation band of the radical-ion complexes.
Measurement and Analysis of the ν3 Band of CF4
Authors: Suzuki Tetsuo , Okada Hiroshi , Fujiyama Tsunetake
Published: July 2006

The ν3 fundamental of carbon tetrafluoride has been measured with a tunable diode laser-source spectrometer. The following molecular constants were obtained: ν0−2(Bζ3)eff=1283.4067 cm−1, BeffPR+B0−2(Bζ3)eff=7.210×10−2 cm−1, BeffPR–B0=−5.290×10−4 cm−1, and δ3=6.153×10−4 cm−1. Using the rg-structure obtained from the gas-electron diffraction study, the above molecular constants were reduced to be: ν0=1283.7181 cm−1, BeffPR=0.1915 cm−1, B0=0.1920 cm−1, and (Bζ3)eff=0.1557 cm−1. From the (Bζ3)eff value, the Coriolis coupling constant for the ν3 was estimated to be ζ3=0.811.
Asymmetric Cyclization of Propylene Chlorohydrins Catalyzed by an Optically Active Cobalt(salen) Type Complex
Authors: Takeichi Tsutomu , Ishimori Michihiro , Tsuruta Teiji
Published: July 2006

By using an optically active cobalt complex, N,N′-disalicylidene-(1R,2R)-1,2-cyclohexanediaminatocobalt(II), as a catalyst, optically active methyloxirane was synthesized by the asymmetric elimination of hydrogen chloride with a base from racemic propylene chlorohydrins. The highest optical purity of methyloxirane so far obtained was 35%, observed when 2-chloro-1-propanol and potassium carbonate were used as substrate and base, respectively. The optical rotations of the products and of the unchanged substrates indicate that (S)-1-chloro-2-propanol reacted selectively to produce (S)-methyloxirane, whereas in the case of 2-chloro-1-propanol, the (R)-isomer was preferentially cyclized to give (S)-methyloxirane with inversion of the asymmetric carbon. The physicochemical data of the circular dichroism and absorption spectra indicated a complexation of the optically active cobalt(II) species with potassium carbonate, either the (R)- or (S)-substrate interacting selectively with the Co*/K2CO3complex formed, followed by cyclization of the substrate.
A New Peptide Synthesis Using 2-Fluoro-1,3,5-trinitrobenzene. Syntheses of Thyrotropin Releasing Hormone and Leucine–Enkephalin
Authors: Kinoshita Hideki , Inomata Katsuhiko , Miyano Osamu , Kotake Hiroshi
Published: July 2006

2-Fluoro-1,3,5-trinitrobenzene has been found to be a useful new condensing reagent for peptide synthesis. A variety of dipeptides have been prepared from the corresponding amino acids with the reagent. The Young test under certain conditions did not cause racemization during the procedures. Subsequent application of this reagent enabled the syntheses of thyrotropin releasing hormone and leucine-enkephalin in good yields.
One-electron Reduction of 1-Benzyl-3-carbamoylpyridinium as a NAD+ Model
Authors: Ohnishi Yutaka , Kitami Miyoko
Published: July 2006

The pyridyl radical generated chemically or electrochemically by the le-reduction of 1-benzyl-3-carbamoylpyridinium undergoes dimerization to give mainly four dimers, diastereomers of 4,4′- and 4,6′-linked dimers. Isomerization between the dimers proceeds readily.
The Photo-Beckmann Rearrangement of A-Nor-5α-cholestan-3-one Oxime
Authors: Suginome Hiroshi , Takeda Hiroshi , Masamune Tadashi
Published: July 2006

The photo-Beckmann Rearrangement of A-nor-5α-cholestan-3-one oxime affords 4-aza-5α-cholestan-3-one and 3-aza-5α-cholestan-4-one as the only lactams.
Molecular Structure of Bromoform as Determined by a Joint Analysis of Electron Diffraction and Microwave Data
Authors: Tamagawa Koichi , Kimura Masao
Published: July 2006

The gas phase molecular structure of bromoform has been studied by electron diffraction. By a joint analysis of the diffraction results and the moments of inertia for CH79Br3, CD79Br3, CH81Br3, and CD81Br3 obtained by Williams et al., the bond distances in rg and the bond angles in \varphiav have been determined as follows: rg(C–Br)=1.924±0.005 Å, rg(Br…Br)=3.175±0.003 Å, rg(C–H)=1.111±0.046 Å, \varphiav(BrCBr)=111.7±0.4°, and \varphiav(HCBr)=107.2±0.5°. The uncertainties represent the estimated limits of error. The anharmonicity parameter of the Morse-type potential, a3, for the nonbonded Br…Br atom pair has been estimated as −1.3±0.9 Å−1.
Binding Forces Contributing to the Association of Cyclodextrin with Alcohol in an Aqueous Solution
Authors: Matsui Yoshihisa , Mochida Kazuo
Published: July 2006

The association constants and thermodynamic parameters were determined for complexes of α- and β-cyclodextrins (CD) with a variety of alcohols (ROH) by the spectrophotometric examination of the inhibitory effect of ROH on the association of CD with azo dyes, and they were analyzed in connection with the partition coefficients of ROH in a diethyl ether–water solvent system in order to elucidate the binding forces contributing to the association of CD with an organic substrate. Hydrophobic and van der Waals interactions were of primary importance in the complexation. Among them, the latter was preferential in α-CD–1-alkanol adducts, while the former, in β-CD–1-alkanol adducts. As the bulkiness of ROH increased, the stability of the α-CD adduct was lowered owing to van der Waals repulsion between ROH and the relatively small α-CD cavity, whereas that of the β-CD adduct was enhanced by the attainment of the close van der Waals contact of ROH with the relatively large β-CD cavity.
Magnetic Study of N,N,N′,N′-Tetramethyl-p-phenylenediamine (Wurster’s Blue) Tetrafluoroborate Cation Radical
Authors: Yamauchi Jun , Fujita Hideo , Deguchi Yasuo
Published: July 2006

Wurster’s Blue cation radical, which is composed of TMPD cation and BF4 anion moieties, was prepared and its magnetic properties were examined. The cation radical shows similar magnetic behavior to that of the TMPD–ClO4 cation radical, but there is a slight perturbation when changing the counteranions from perchlorate to tetrafluoroborate. A phase transition takes place at 190.5 K, which is attributable to a dimerization involving a small molecular displacement in the crystal lattice. These phenomena are discussed using the magnetic susceptibility data, thermal study, and ESR observations due to triplet exciton. The magnetic data are described by comparison with Wurster’s Blue perchlorate cation radical.
Enthalpies of Dilution of Aqueous Sodium Chondroitin 4-Sulfate and 6-Sulfate
Authors: Tsuge Hideya , Yonese Masakatsu , Kishimoto Hiroshi
Published: July 2006

Enthalpies of dilution of aqueous sodium chondroitin 4- and 6-sulfate were measured by a microcalorimeter from the various initial concentrations m=0.16–0.07 monomole kg−1 to the final concentration m′=3.85×10−3monomole kg−1 at various temperatures. The concentration and temperature dependencies of measured enthalpies well agreed quantitatively with the theoretical ones calculated by Manning’s limiting law, when the distance between the neighboring charges of polyion, b, was assumed to be 4.8 Å, which was obtained from X-ray diffraction measurement.
An Analysis of Impedance in the Kolbe Reaction on Platinum and Gold Anodes in Aqueous Acetate Solutions
Authors: Sekine Isao , Ohkawa Hideki
Published: July 2006

The Kolbe reaction occurring on platinum or gold anodes in aqueous acetate was studied by analyzing the equivalent circuit of the impedance obtained with a phase-sensitive detector. In the case of platinum, the equivalent circuit at the potential for the Kolbe reaction is represented by a parallel combination of the double-layer capacity, Cdl, and the charge-transfer resistance, θ, in series with the solution resistance, Rsol. The Cdl value of 2.00 V obtained by a complex impedance plane plot is nearly identical to that calculated by assuming that the Helmholtz layer is occupied by CH3COO−. In the potential range more negative than 2.00 V, the Kolbe reaction occurs. The steep decrease in the differential capacity is considered to be a result of the decrease in the adsorption pseudocapacity. The θ value of the oxygen evolution increases with an increase in the acetate concentrations. It is shown that the surface coverage of CH3COO− may be obtained by “Frumkin’s treatment” in conjunction with the high-frequency capacitance, CHF, and the low-frequency capacitance, CLF, from the complex capacitance plane plot (Y/ω plane plot). The Kolbe reaction does not occur at all with gold anodes, and the specific circular arc was not seen in the Y/ω plane plot. Impedance measurements, therefore, confirm that an adsorption pseudocapacity of CH3COO− is not present with gold anodes.
Reversible Binding of NO to Fe(II)edta
Authors: Hishinuma Yukio , Kaji Ryuichi , Akimoto Hidetoshi , Nakajima Fumito , Mori Toshikatsu , Kamo Tomoichi , Arikawa Yoshijiro , Nozawa Shigeru
Published: July 2006

The equilibrium constants, enthalpy, and entropy of the reversible binding of nitrogen oxide to Fe(II)edta in an aqueous solution have been measured in the temperature range 38.5 to 70 °C. Experiments were carried out by absorbing NO under O2 free conditions. The results show that, in the absorption of NO with Fe(II)edta solution, the value of ΔH° is −15.8 kcal/mol and ΔS° is −20.7 e.u.
An X-Ray Photoelectron Spectroscopic Study of 2-Mercaptobenzothiazole Metal Complexes
Authors: Yoshida Tooru , Yamasaki Kiyoshi , Sawada Shigemasa
Published: July 2006

The X-ray photoelectronic spectra of 2-mercaptobenzothiazole (LH) and its metal complexes have been measured. On the basis of the chemical shifts of the N(1s), S(2p), and Cu(2p3⁄2) electron binding energies, the coordination mode of the ligand and the oxidation state of the copper atom have been examined. It is suggested that, in HgL2, PbL2, AgL, and CuL3H2Cl complexes, the ligand is solely coordinated through the exocyclic sulfur atom, and that, in CuL, CuL2, PtL2, PdL2, NiL2, and CdL2 complexes, the ligand is coordinated through both the exocyclic sulfur and nitrogen atoms. In CuL2 and CuL3H2Cl, it was found that the copper was present in a (+1) oxidation state, and that part of the ligand molecules, bis(benzothiazol-2-yl) disulfide, resulted from oxidation of LH by the Cu2+ ion on complex formation.
The Synthesis of 5,2′-Dihydroxy-6,8-dimethoxyflavone and Its Isomers: A Revised Structure of Skullcapflavone I
Authors: Horie Tokunaru , Tsukayama Masao , Masumura Mitsuo , Nakayama Mitsuru , Hayashi Shûichi
Published: July 2006

5,2′-Dihydroxy-6,8-dimethoxyflavone, which had been proposed as the structure of skullcapflavone I isolated from Scutellaria baicalensis Georgi, was synthesized from 2-hydroxy-3,5,6-trimethoxyacetophenone. However, the synthetic flavone was not identical with the natural flavone. Thus, two isomeric flavones, 5,2′-dihydroxy-7,8-dimethoxyflavone and 5,2′-dihydroxy-6,7-dimethoxyflavone, were prepared from the corresponding acetophenones; the structure of skullcapflavone I was confirmed to be 5,2′-dihydroxy-7,8-dimethoxyflavone.
Reduction of Methylene Blue with l-Ascorbic Acid or l-Cysteine in Micellar Systems
Authors: Sen\={o} Manabu , Kousaka Kouichi , Kise Hideo
Published: July 2006

The reduction of Methylene Blue (MB) with l-ascorbic acid to the corresponding leuco compound has been studied in aqueous surfactant solutions. The reduction was accelerated in the presence of cationic surfactant hexadecyltrimethylammonium bromide, but tetrabutylammonium bromide, which has no ability of micelle formation, does not show any effects on the reaction rate. The micellar effects are largely affected by pH of the medium, and the rate enhancing effects of the micelles are retarded by KCl. These results could be interpreted by the change in dissociation state of the substrate on the micelle surface and by the binding of the reaction product, leuco MB, to the micelles. The binding site of leuco MB was found to be outer core of the HTAB micelle by NMR. Similar results were obtained in the reduction of MB with l-cysteine, although the reduction did not proceed without the addition of cationic surfactant. The interaction between dissolved oxygen and the substrate in HTAB micellar solutions was also investigated.
The Photochemical Dimerization of 2-Acyl-1,4-quinones
Authors: Miyagi Yo , Maruyama Kazuhiro , Ishii Hideo , Mizuno Sachie , Kakudo Masao , Tanaka Nobuo , Matsuura Yoshiki , Harada Shigeharu
Published: July 2006

2-Acyl-1,4-benzoquinones and 2-acyl-1,4-naphthoquinones underwent a novel type of regiospecific and stereospecific cyclodimerization by photolysis. The reaction was general, being not affected by any variation in the substituents and solvents. The structure of the dimers was elucidated as 4aα-acyl-10β-alkyl-5,8-dihydroxy-4aα,10aα-dihydro-1,4,9(10H)-phenanthrenetriones and dibenzo [b,h] homologues (8). The structure of 8 suggests that the dimerization proceeds through cis-ring fusion, disposing two substituents of the dimer (an acyl and an alkyl group) to a trans configuration.
Decomposition of Ozone on Natural Sand
Authors: Suzuki Shin , Hori Yoshio , Koga Osamu
Published: July 2006

Ozone decomposition on natural sand has been studied with a flow system. Ozone decomposed significantly on natural sand and in particular on iron sand. Silica, alumina, and iron oxides, the major components of the sand, were also capable of decomposing ozone.
Convenient Preparation of Furanoeremophilane and Menthofuran
Authors: Sato Toshichika , Tada Masahiro , Takahashi Takeyoshi
Published: July 2006

Pulegone was transformed into isopulegone enol acetate or isopulegone ethylene acetal, which was treated with m-chloroperbenzoic acid and then with acid to give menthofuran. Fukinone was converted into furanoeremophilane by the same procedure.
Theory of A.c. Polarization and A.c. Polarography and Voltammetry of Surface Redox Reaction
Authors: Kakutani Tadaaki , Senda Mitsugi
Published: July 2006

Theoretical equations are presented of the a.c. polarization and of the a.c. polarography and voltammetry for the surface redox reaction (Oad+ne\ightleftharpoonsRad) in which charge transfer reaction takes place exclusively between the adsorbed reactants Oad and Rad, and both reactants are adsorbed so strongly that the amount of O or R brought to or removed from the electrode surface can be neglected. The interaction between adsorbed molecules is assumed to be expressed by Frumkin’s a-parameters. Also the effect of the double layer impedance is taken into account. Some simplified cases are discussed in detail.
Crystal Structure and Related Physical Properties of [N,N,N,N′,N′,N′-Hexamethylhexamethylenediammonium]2+-[Tetracyanoquinodimethane]42−: as a Two-dimensional Magnetic System
Authors: Flandrois Serge , Chasseau Daniel , Delhaes Pierre , Gaultier Jacques , Amiell Jacques , Hauw Christian
Published: July 2006

The crystal structure, electrical conductivity and magnetic properties of (HMHDA)(TCNQ)4 are studied. It appears that this ion-radical salt consists of planar arrays of (TCNQ)2− dimers (diads) in weak interaction. The structure may thus be considered as quasi two-dimensional, the magnetic behavior being in line with two-dimensionality.
The Photochemical Reaction of Benzo[c]cinnoline. II. Photo-reduction in Acidic 2-Propanol
Authors: Inoue Hiroyasu , Hiroshima Yukimi , Makita Norio
Published: July 2006

The photochemical reduction of benzo[c]cinnoline in strongly acidic 2-propanol (4 M HCl) has been studied using light of wavelength longer than 400 nm. The photoproduct has been identified as 5,6-dihydrobenzo[c]cinnoline. The quantum yields for product formation, which are the same as that for the disappearance of the reactant, have been measured under various conditions. In contrast to the poor phosphorescent property of benzo[c]cinnoline, the protonated species has been found to phosphoresce with significant efficiency. The lowest triplet state energy has been estimated to be 51 kcal/mol. The results of the quenching showed that the photoreduction was attributed to the lowest excited triplet state of protonated benzo[c]cinnoline. The pKa value in the reactive state is lower than that in the ground state.
Conformational Transition of Poly(l-glutamic acid) in Aqueous Decylammonium Chloride Solution
Authors: Satake Iwao , Gondo Takeshi , Kimizuka Hideo
Published: July 2006

The cooperative binding of decylammonium chloride to poly(l-glutamic acid) (PLG) was studied by the potentiometric measurement of the binding isotherm at pH 7.9. Circular dichroism spectra were also measured as a function of the degree of binding of surfactant ion (x). It was shown that the coil to α-helix transition of PLG-surfactant complex takes place with a change in x. PLG did not undergo an appreciable conformational change in the range of x below 0.55. But the helical content increased suddenly with further increase in x. An abrupt increase in the helical content of PLG-surfactant complex can be well interpreted in terms of the hydrophobic interaction among bound surfactant ions. On the basis of the theoretical analysis of the cooperative binding isotherm, it was concluded that the formation of a micelle-like cluster consisting of at least eight surfactant ions is required for the stabilization of a surfactant induced helical structure.
Chemistry of N-Thiosulfinylanilines. IV. Reactions of N-Thiosulfinyl-anilines with Electrophilic Reagents
Authors: Inagaki Yoshio , Okazaki Renji , Inamoto Naoki
Published: July 2006

Reaction of 2,4-di-t-butyl-6-methyl-N-thiosulfinylaniline (1) with m-chloroperbenzoic acid (MCPBA) afforded the corresponding aniline and N-sulfinylaniline. Reaction of MCPBA with 2,4,6-tri-t-butyl-7,8-dithia-9-azabicyclo[4.3.0]nona-2,4,9-triene equilibrated with 2,4,6-tri-t-butyl-N-thiosulflnylaniline gave 2,4,r-6-tri-t-butyl-7,8-dithia-9-azabicyclo[4.3.0]nona-2,4,9-triene t-7-oxide (12), 4,6-di-t-butyl-3H-1,2,3-benzodithiazole 2-oxide (13), and 2,4,6-tri-t-butyl-N-sulfinylaniline (14). The oxide 13 was considered to be produced via a primary product 2,4,r-6-tri-t-butyl-7,8-dithia-9-azabicyclo[4.3.0]nona-2,4,9-triene t-8-oxide which was found to be unstable above −30 °C. Thermolysis of 12 affording 13, 14, and 2,4,6-tri-t-butylaniline demonstrated oxygen or sulfur migration in the thiosulfinate type compound. Bromine reacted with 1 to give bis(2,4-di-t-butyl-6-methylphenyl)sulfur diimide probably via a thionitroso intermediate. Neither trimethyloxonium tetrafluoroborate nor trimethylsilyl chloride reacted with 1.
Catalytic Hydrolysis of p-Nitrophenyl Esters in the Presence of Representative Ammonium Aggregates. Specific Activation of a Cholesteryl Nucleophile Bound to a Dialkylammonium Bilayer Membrane
Authors: Okahata Yoshio , Ando Reiko , Kunitake Toyoki
Published: July 2006

Catalytic hydrolysis of p-nitrophenyl esters (acetate and nonanoate) by hydroxamate and imidazole nucleophiles was studied at 30 °C in the presence of aqueous aggregates of single-chain (hexadecyl), double-chain (didodecyl and dioctadecyl) and triple-chain (trioctyl) ammonium amphiphiles. These three types of ammonium salts give rise to very different aggregate morphologies. The rate constant of ester cleavage by the nucleophiles was enhanced several hundred folds in the presence of these hydrophobic aggregates. Simple long-chain nucleophiles possessed esterolytic reactivities which reflect the hydrophobic microenvironment of the respective aggregates: single-chain<double-chain<triple-chain. On the other hand, the cholesteryl ester of imidazolecarboxylic acid showed an especially high reactivity when bound to the didodecylammonium bilayer. Cholic acid-derived nucleophiles showed normal reactivity patterns. Apparently, specific binding of the cholesterol derivative to the bilayer is responsible for the unusual catalytic behavior.
Effects of Pressure on the Cloud Point of Nonionic Surfactant Solutions and on the Solubilization of Hydrocarbons
Authors: Kaneshina Shoji , Shibata Osamu , Nakamura Makoto
Published: July 2006

Cloud points in 1.0 wt% aqueous solutions of penta- and hexa(oxyethylene) dodecyl ether increase monotonously with an increase of pressure up to 150 MPa. The elevation of the cloud-point temperature with pressure was 1.05×10−7 and 1.09×10−7 K Pa−1 for respective surfactant. Both volume and enthalpy changes on the separation of the surfactant-rich phase had the positive values. The rise of cloud points on compression is attributable to the enhancement of the hydrogen bonds formation between water and ether oxygens of the poly(oxyethylene) group and partly to the disruption of the “hydrophobic bonding.” The cloud-point temperature at conscant pressure and the cloud-point pressure at constant temperature were also examined as a function of the amount of solubilizate such as hexane and octane. There was an optimum pressure at a given temperature, as well as an optimum temperature at a given pressure, at which the solubilizing power of surfactant is maximum.
Polysoap as a New Titrant for the Determination of Sodium Dodecylbenzenesulfonate by Colloid Titration
Authors: Ono Toshiro , Miyata Haruo , Tôei Kyoji
Published: July 2006

A colloid titration method for the determination of sodium dodecylbenzenesulfonate (LAS) with poly(4-vinyl-1-pentylpyridinium bromide) (polysoap) is described. The end-point detection is based on the measurement of turbidity, the transmittance at 420 nm or 680 nm being used for the determination. The most successful results were obtained by titrating LAS (1–7.5×10−4  n) with 2.5×10−3  n polysoap solution. The purity of commercial LAS was found to be 81–84%.
A Synthetic Study of the Solid Solutions in the Systems and La2(CH3)3·8H2O-Ce2(CO3)3·8H2O and La(OH)CO3–Ce(OH)CO3
Authors: Wakita Hisanobu , Kinoshita Setsuko
Published: July 2006

The solid solutions in the systems La2(CO3)3·8H2O–Ce2(CO3)3·8H2O and La(OH)CO3–Ce(OH)CO3 have been synthesized by the hydrolysis of the lanthanum–cerium trichloroacetates. The X-ray diffraction data of the solid solutions of La2(CO3)3·8H2O–Ce2(CO3)3·8H2O indicated a lanthanite-type structure while the data of La(OH)CO3–Ce(OH)CO3 indicated a bastnaesite-type structure. The correlations between lanthanite, bastnaesite, and calkinsite, and the lanthanite-bastnaesite transformation are discussed.
Proton Magnetic Resonance Studies of 4-(2-Pyridylazo)resorcinol (PAR) and Its Cobalt(III) Complexes
Authors: Mochizuki Katsura , Ito Tasuku , Fujimoto Masatoshi
Published: July 2006

The 1H NMR spectra of PAR, [CoIII(par)2]−, and [CoIII(par)(dien)]+ were measured in D2O solutions. The signals were assigned. The deuteration of H7 was observed in D2O solutions of free ligand PAR around pD 9–10, where PAR exists in the form of LH− having an intramolecular hydrogen-bond. The significant up-field shift for the resonance of H1 was observed in [CoIII(par)2]− but not in [CoIII(par)(dien)]+. The shift was interpreted in terms of the magnetic anisotropy due to the π-electron system of the neighboring PAR molecule in the complex. The down-field shift for the resonance of the H5 signal of the cobalt(III) complexes reflects the structural change of PAR upon chelate-ring formation. PAR coordinates to cobalt(III) ion in planar terdentate fashion, viz., in a mer configuration.
Hydrates of Organic Compounds. IV. Clathrate Hydrates of Various Bolaform Salts
Authors: Nakayama Haruo
Published: July 2006

The solid-liquid phase diagrams are presented for binary mixtures of water with various polymethylene-bis(tributylammonium) difluorides, [(n-C4H9)3N(CH2)nN(n-C4H9)3]F2 (n=4, 5, 6, 8, and 10); and with hexamethylenebis(tributylammonium) dihydroxide and its salts, [(n-C4H9)3N(CH2)6N(n-C4H9)3](X2 or Y) (X=OH, Cl, and Br; Y=OOC–COO and OOC–(CH2)3–COO). It has been found that all the compounds form congruently melting hydrates which have large hydration numbers. The hydrates appear to be clathrate-like hydrates essentially similar to those formed by many tetrabutyl(or isopentyl) ammonium salts. The most stable hydrate found in this study is [(n-C4H9)3N(CH2)6N(n-C4H9)3]F2 hydrate (mp 20.4 °C). The melting points of hexamethylenebis(tributylammonium) hydrates have been compared with those of the corresponding tetrabutylammonium hydrates.
Mutual Catalysis in the Chromium(III)–EDTA–Hydrogen Peroxide System
Authors: Beck Mihály T , Tóth Zoltán
Published: July 2006

Hydrogen peroxide catalyzes the reaction between hexaaquachromium(III) and ethylenediaminetetraacctic acid, while chromium(III)–EDTA complex accelerates the decomposition of hydrogen peroxide. A mechanism is suggested for the reaction on the basis of gasvolumetric and spectrophotometric experiments.
Ultrasonic Properties of Aqueous Solutions of Butylamines
Authors: Nishikawa Sadakatsu , Mashima Mitsuo
Published: July 2006

Ultrasonic absorption and velocity measurements were performed in aqueous solutions of t-butylamine and isobutylamine at 20 °C. Two relaxational absorptions were found in both solutions. One is associated with the proton transfer reaction, the rate constants being determined together with the standard volume change of the reaction. No effect was observed on Kf with change in molecular structure. The other, associated with the peak sound absorption concentration, is ascribed to the association-dissociation reaction mechanism of unionized amine molecules. The results are discussed in comparison with those of butylamine.
The Formation of Mg-bearing Ferrite by the Air Oxidation of Aqueous Suspensions
Authors: Kaneko Ken , Katsura Takashi
Published: July 2006

When the Mg2+/Fetotal molar ratio in the initial aqueous suspension is below 0.1 at pH 9.0 and 65 °C, almost all Mg2+ is incorporated into the spinel type ferrite by the air oxidation of Fe(OH)2. The chemical composition of the Mg-bearing ferrite thus obtained is not stoichiometric, and is expressed as the MgFe2O4–Fe3O4–γ-Fe2O3system. When the Mg2+/Fetotal ratio exceeds 0.1, the excess Mg2+ produces a basic magnesium sulfate which has a composition of [Mg1.002+, Na0.64+] [OH1.36−,(SO42−)0.64]. At pH 8.0, a small amount of the Mg2+ is incorporated into the ferrite, between pH 9.0 and 10.0 only the Mg-bearing ferrite is formed, and at pH 11.0, the α-FeOOH type compound is formed together with the Mg-bearing ferrite.
Preparation and Characterization of uns-cis-Trimethylenediamine-N,N′-diacetato Cobalt(III) Complexes with Several l-Amino Acids
Authors: Okabayashi Minahiro , Igi Kozo , Hidaka Jinsai
Published: July 2006

Five uns-cis-mer and two uns-cis-fac complexes of (trimethylenediamine-N,N′-diacetato)(l-amino carboxylato)cobalt(III) were prepared, where l-amino carboxylate denotes l-alaninate, l-valinate, l-prolinate, l-hydrogen aspartate, or l-hydrogen glutamate ion. The complexes were separated into the fourteen isomers, Δ-, Λ-uns-cis-mer for the l-alaninato, l-valinato, and textscl-prolinato complexes, and Δ-, Λ-uns-cis-mer and Δ-, Λ-uns-cis-fac for the l-hydrogen aspartato and l-hydrogen glutamato complexes. They were characterized by their proton magnetic resonance, absorption and circular dichroism spectra. Each of the uns-cis-mer and uns-cis-fac isomers showed the characteristic CD behavior in the second absorption band region. The Λ-uns-cis-mer and Δ-uns-cis-fac isomers of the l-aspartato and l-glutamato complexes were stereoselectively formed, the formation ratios of the isomers being estimated spectrophotometrically.