bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxygen-plasma Treatment of Packing Materials for Gas Chromatography. The Incorporation of Oxygen into the Hydrocarbon Liquid Phase and the Formation of Crosslinked Products on the Support Surface
Authors: Yamamoto Yukio , Oka Seiji , Hayashi Koichiro 
Published: July 2006

Abstract
The oxygen-plasma treatment of column packings for gas chromatography was examined with diatomaceous earth coated with several kinds of stationary liquid phases from the point of view of the modification of their chromatographic properties. A remarkable effect on the gas chromatograms of polar compounds was observed for the packings with nonpolar liquids, such as squalane and Apiezon L. The elimination of tailing and the improvement of the resolution by the plasma treatment were attributed to the incorporation of oxygen into the hydrocarbon liquids and the formation of crosslinked products covering the adsorptive support surface. These results were compared with the previous data on argon-plasma treatment.
Cycloaddition Reactions of Azepines and Diazepines with Conjugated Double Bonds Possessing Electron-Withdrawing Groups
Authors: Saito Katsuhiro , Iida Shigenori , Mukai Toshio 
Published: July 2006

Abstract
Cycloadditions of 1-ethoxycarbonyl-1H-azepine with 5-methoxycarbonyl-2-pyrone gave [4+2] and [4+6] type adducts and a benzazepine derivative, while the reaction of the azepine derivative with 3-methoxycarbonyl-2-pyrone afforded only a [4+2] type adduct. Similarly, an addition of 1-ethoxycarbonyl-1H-1,2-diazepine with 5-methoxycarbonyl-2-pyrone gave a benzodiazepine derivative. Reactions of the azepine and the diazepine derivatives with tetrachlorocyclopentadienone dimethyl acetal afforded [4+2] type adducts.
Syntheses and Physical Properties of Several Polyphenylenes Containing Mixed Linkages
Authors: Fujioka Yasuhiro 
Published: July 2006

Abstract
Fourteen macrocyclic polyphenylenes, including the following ten new compounds, were synthesized by intra- or intermolecular homo-coupling of di-Grignard compound and by cross-coupling of two kinds of di-Grignard compounds with copper(II) chloride: m,m,o,p,o-pentaphenylene; o,o,p,o,o,p-, m,o,p,m,o,p-, o,p,o,p,o,p-, m,o,p,o,p,o-, m,o,m,o,m,o-, and m,m,m,o,m,o-hexaphenylene; m,o,p,p,o,m,p-, and m,m,m,m,p,o,p-heptaphenylene; and m,o,o,m,o,o,m,o,o,m,o,o-dodecaphenylene. 1H NMR spectra of the polyphenylenes, compared with those of open-chain analogues, provide valuable information on the nonplanar spacial relationship of constituting phenylene rings. UV spectra of the compounds containing p-phenylene ring(s) suggest that the lack or decrease in intensity of K-band above ca. 260 nm or a marked shift of that band provides useful conformational information. Empirical Hückel molecular orbital calculations of longest-wavelength absorption bands of twelve polyphenylenes were also carried out. The calculations furnish additional bases for their conformational aspects deduced from their spectral data and Dreiding stereomodels. IR spectra indicate that lack of intense band(s) near 700 cm−1 may generally be regarded as a piece of plausible evidence for the macrocyclic structure containing no m-phenylene ring. Stabilities of the polyphenylenes to electron bombardment are also discussed.
The in situ-Generated Nickel(0)-catalyzed Homo-coupling of Alkenyl Halides with Zinc Powder. A Specific Outcome in Stereochemistry
Authors: Takagi Kentaro , Mimura Harutaka , Inokawa Saburo 
Published: July 2006

Abstract
The catalytic activity of nickel(0) generated in situ from nickel(II) salt was examined in a dehalogenative coupling of alkenyl halides with zinc powder. The reaction of alkenyl bromides took place provided that potassium iodide was present to assist the reduction of nickel(II) with zinc powder, and also to convert the alkenyl bromides to the corresponding alkenyl iodides. A speculative view concerning the disproportionation step is advanced in an attempt to explain the unique stereochemistry observed.
Syntheses of 23-Dialkylamino-23-deoxydemycinosyltylosins and Conformational Study of Mycaminosyl Tylonolide by Nuclear Overhauser Difference Spectroscopy
Authors: Sakamoto Shuichi , Tsuchiya Tsutomu , Miyake Toshiaki , Tanaka Akihiro , Umezawa Sumio 
Published: July 2006

Abstract
23-Dialkylamino-23-deoxydemycinosyltylosins have been prepared by treating 23-deoxy-23-iododemycinosyltylosin (2) with a series of amines including dimethylamine, diethylamine, and piperidine. 14(23)-Unsaturated derivatives, 23-deoxy-14(23)-enomycaminosyl tylonolide (17) and 23-deoxy-14(23)-enodemycinosyltylosin (4) have also been prepared. The conformation of mycaminosyl tylonolide dissolved in chloroform-d was determined by nuclear Overhauser difference spectroscopy, revealing that the two three-member groups of H(10), Me(22), and H(14) and of H(11), H(13), and H(15) stood, respectively, in a line in this order.
Molecular Structure of [2]Paracyclo[2](2,5)furanophane
Authors: Hama Fumio , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami 
Published: July 2006

Abstract
The molecular structures of [2]paracyclo[2](2,5)furanophane (1) at 20 °C and −150 °C have been determined by means of X-ray diffraction. The crystal is tetragonal, with a=15.996(1), c=8.374(1)Å (at 20 °C), and a=15.823(3), c=8.330(3)Å (at −150 °C), space group P\bar421c and Z=8. The structures were solved by the direct method, and refined anisotropically by the block-diagonal least-squares procedure: R=0.069 and 0.075 for the structures at 20 °C and −150 °C, respectively. The furan ring has an envelope form, and the benzene ring boat-shape.
Coexistence of Hydrogen Atom Transfer Reactions through and not through Triplet Ion Pair between p-Chloranil and Durene
Authors: Kobashi Harumichi , Funabashi Masa-aki , Kondo Tomoyuki , Morita Toshifumi , Okada Tadashi , Mataga Noboru 
Published: July 2006

Abstract
Mechanisms of hydrogen atom abstraction reactions by triplet state p-chloranil (3CA) from durene (DH) were studied by picosecond and nanosecond laser photolysis and transient photoconductivity measurements. 3CA was quenched by DH through diffusional encounter to form a triplet ion pair (IP) between CA and DH, p-chloranil semiquinone radical (CAH·), and 2,4,5-trimethylbenzyl radical (D·). Ionic dissociation of IP was observed in 1,2-dichloroethane (DCE) as well as in acetonitrile. However, no transient species was observed by direct excitation of a charge-transfer (CT) band of the electron donor-acceptor (EDA) complex between CA and DH. The H-atom transfer leading to production of CAH· was found to proceed through two distinct mechanisms; H-atom transfer via IP (Mechanism I) and a more rapid transfer competing with IP formation (Mechanism II). The quantum yields of CAH· produced by Mechanisms I and II and the first-order rate constants for proton transfer, ionic dissociation, and intersystem crossing competing with one another in the IP state were estimated to be (0.1 and 0.2) and (2, 5, and 13)×106 s−1, respectively, in DCE at room temperature.
Structural Study of Germanate Glasses by 119Sn Mössbauer Spectroscopy
Authors: Nishida Tetsuaki , Katada Motomi , Takashima Yoshimasa 
Published: July 2006

Abstract
Mössbauer study of potassium germanate glasses containing a small amount of Sn4+ has been performed to know the relationship between the abnormal composition dependence of physical properties, so-called germanate anomaly, and the local structural change of the glasses. Distinct increases in isomer shift and linewidth and a distinct decrease in quadrupole splitting are observed when the concentration of alkali oxide exceeds about 16 mol%. These changes are ascribed to the formation of nonbridging oxygen atoms in GeO4 units. This is also supported by a drastic decrease in a parameter of intermolecular force constant obtained from the temperature dependence of Mössbauer absorption area. The composition dependence of the parameter is well consistent with that of glass transition temperature (Tg) of the same samples. Transformation of GeO4 tetrahedra into GeO6 octahedra is also confirmed by increases in the parameter of intermolecular force constant and in Tg in the alkali content region lower than 16 mol%. The role of Sn4+ is concluded to be a network modifier which is present at an interstitial site of three-dimensional network composed of GeO4 and GeO6 units.
Vibronic-Level Dependence of the Radiative Decay Rate in Pyrazine and Pyrimidine Vapors: Re-examination under High Spectral Resolution
Authors: Sekiguchi Osamu , Ohta Nobuhiro , Baba Hiroaki 
Published: July 2006

Abstract
The radiative decay rate constants (kF) for vibronic levels in S1 of pyrazine and pyrimidine were derived by using the quantum yields measured under the conditions of SVL excitation. The vibronic level dependence of kF in pyrazine can be explained by the Herzberg-Teller theory.
Orbital Phase Explanation of Regioselectivity of Organic Reactions
Authors: Inagaki Satoshi 
Published: July 2006

Abstract
The regioselectivity of such fundamental organic reactions as electrophilic addition to olefins, Diels-Alder cycloaddition, and electrophilic aromatic substitution, can be explained by the phase continuity-discontinuity properties of orbitals involved in cyclic interaction for acyclic delocalization of electrons.
Dinuclear Cobalt(II) Complexes with Various Dinucleating Ligands and Their Dioxygen Complexes
Authors: Suzuki Masatatsu , Kanatomi Hajime , Murase Ichiro 
Published: July 2006

Abstract
Various types of dinuclear cobalt(II) complexes, [Co2L(CH3COO)2]ClO4, [Co2L(CH3COO)](ClO4)2, [CO2L(OH)](ClO4)2, [Co2L(C3H3N2)]ClO4)2(C3H3N2−)=pyrazolate), and [CO2LX2](ClO4)n, were prepared, where HL represents 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-methylphenol(Hbpmp), 2,6-bis[N-(2-pyridylmethyl)-2-(2-pyridyl)ethylaminomethyl]-4-methylphenol(Hbpmep), 2,6-bis[bis[2-(2-pyridyl)ethyl]aminomethyl]-4-methylphenol(Hbpmep), and 2,6-bis[bis(2-benzirnidazolylmethyl)aminometnyl]-4-metnylphenol(Hbbimp), and X is N3−, NCS−, Cl−, Br−, H2O, or py(pyridine). The electronic spectra and magnetic moments of the complexes revealed that [Co2L(CH3COO)2]ClO4 (L=bpmp, bpmep, or bpep) are high-spin octahedral, whereas the other complexes have five-coordinate structure of high-spin configuration. Some of the bpmp and the bpmep complexes reacted reversibly with molecular oxygen more or less. The P1⁄2 of some complexes were determined spectrometrically. The oxygen affinities of the complexes are highly dependent on the natures of the dinucleating ligands and additional bridging or unidentate ligands.
Studies of Unusual Amino Acids and Their Peptides. XV. The Chemistry of N-Carboxymethyl Amino Acids. III. The Synthesis of N-Tosyl-N-carboxymethyl Amino Acid Derivatives by N-Alkoxycarbonylmethylation
Authors: Miyazawa Toshifumi , Yamada Takashi , Kuwata Shigeru 
Published: July 2006

Abstract
The alkoxycarbonylmethylation of the amide nitrogen of N-tosyl amino acid esters with iodoacetic acid esters in the presence of silver(I) oxide in N,N-dimethylformamide afforded the corresponding N-tosyl-N-carboxymethyl amino acid esters in good yields without racemization of the amino acids.
Kinetic Study of Proton Tunneling in the Reaction between 2,4,6-Trinitrotoluene and 1,8-Diazabicyclo[5.4.0]undec-7-ene in Benzonitrile
Authors: Sugimoto Naoki , Sasaki Muneo , Osugi Jiro 
Published: July 2006

Abstract
The proton tunneling has been examined for the reaction between 2,4,6-trinitrotoluene and 1,8-diazabicyclo[5.4.0]undec-7-ene in benzonitrile in view of the solvent effect on the rate ratio kH⁄kD as well as on the various activation parameters. The reaction rate ratio kH⁄kD diminishes from 18.3 at 15 °C to 14.5 at 35 °C. The difference in the activation energies EaD–EaH is 8.8 kJ mol−1 and the ratio of Arrhenius preexponential factors is 2.5. All these values are greater than the semiclassical limits of the primary kinetic isotope effects. According to Bell’s equation the remarkable isotope effect is due to considerable contribution from tunneling in benzonitrile. The present results, being compared with those in other aprotic solvents, are discussed in relation with the effects of solvent polarity, specific acid–solvent interaction, and geometrical bulkiness in the vicinity of the reaction site.
The Reactions of (Trichlorostannato)rhodates(III) with Trichlorostannate(II) in Hydrochloric Acid Solutions
Authors: Iwasaki Shigemi , Nagai Takashi , Miki Eiichi , Mizumachi Kunihiko , Ishimori Tatsujiro 
Published: July 2006

Abstract
(Trichlorostannato)rhodate(III) complexes, [(CH3)4N]3[RhCln(SnCl3)6−n] (n=2, 3, and 4), reacted with tin(II) in hydrochloric acid solutions to form a purple species. This purple species is assumed to be [RhI(SnCl3)5]4−. The formation reaction of the purple species involved two independent paths, fast and slow paths. The main path was the fast one, in which the reactant mixture was in equilibria among [RhCl3(SnCl3)3]3−, [RhCl2(SnCl3)4]3−, [RhCl(SnCl3)5]3−, and probably [Rh(SnCl3)6]3−. The reaction orders in the formation of the purple species were 1, 2, and −2 with respect to the concentrations of the total rhodium(III) complexes, SnCl3−, and Cl− respectively. The absorpton spectra of the reactant mixture showed an interaction absorption between [RhCl2(SnCl3)4]3− and SnCl3−.
Acylations of 2,2-Dimethyl-2H-chromenes
Authors: Yamaguchi Seiji , Yamamoto Satoru , Abe Shoichi , Kawase Yoshiyuki 
Published: July 2006

Abstract
Orientation in acylation reactions of 2,2-dimethyl-2H-chromenes was studied. Five acetylchromenes were obtained with two methods and six formylchromenes were obtained with a third method. Demethylation of four acyl-methoxy-substituted chromenes gave the corresponding acylchromenols. 2,2-Dimethyl-2H-chromene-6-carboxylic acid (anofinic acid) was also obtained by oxidation of 6-formylchromene.
Mass-spectral Isotope Effects in the Metastable Transition of Benzene and Perdeuterio Benzene. Model Calculation
Authors: Arakawa Ryuichi , Yoshikawa Yozaburo 
Published: July 2006

Abstract
The abundances of C6H5+, C6H4+·, C4X4+·, and C3X3+ (X=H, D) fragments occurring in the metastable transition of benzene and perdeuterio benzene have been measured by means of electron-impact ionization. The isotope effects on the relative intensities were reproduced by the simple model calculation on the basis of the RRKM theory. The vibrational frequencies of the transition states for the deuteriated and the nondeuteriated were obtained by a vibrational analysis for the assumed geometries and force fields. The transition states for the C6H5+ and C6H4+· channels preferred a benzene structure while those for the C4H4+· and C3H3+ has a propargylcyclopropene structure. The calculated decay rates for the C6H5+, C4H4+· and C3H3+ fragmentation were compared with those of the photoion photoelectron coincidence (PIPECO) results.
Palladium(II) Complexes Containing Both the Chelating β-Diketonato and σ-Pyridyl Ligands. Catalyzed Coordination-site Exchange Reactions
Authors: Tanaka Hiroshi , Isobe Kiyoshi , Kawaguchi Shinichi , Okeya Seichi 
Published: July 2006

Abstract
A novel type of palladium(II) complexes, [Pd(β-dik)(pyridyl)(PPh3)] and [Pd(β-dik)(pyridyl)]2 containing a chelating acetylacetonate, trifluoroacetylacetonate, or hexafluoroacetylacetonate anion and 2-, 3-, or 4-pyridyl radical as the coexisting ligands were prepared and characterized by elemental analysis and molecular weight determination as well as 1H and 13C NMR spectroscopy. [Pd(acac)(C5H3(6-Cl)N–C2)(PPh3)] is stereochemically rigid in solution but undergoes the coordination-site exchange reaction catalyzed by nitrogen and phosphorus bases and donor solvents. Similar reaction of [Pd(acac)(C5H4N–C2)(PPh3)] is catalyzed by triphenylphosphine liberated by the dinuclear-complex formation reaction (autocatalysis). Intact molecules of [Pd(acac)(C5H4N–C3 and –C4) (PPh3)] catalyze mutually their own coordination-site exchange (self-catalysis).
The Preparation and Properties of Ethylenediamine(2-methyl-8-quinolinolato)cobalt(III) Complexes
Authors: Yamamoto Yoshihisa , Toyota Eiko 
Published: July 2006

Abstract
Ethylenediaminebis(2-methyl-8-quinolinolato)cobalt(III) complexes and bis(ethylenediamine)(2-methyI-8-quinolinolato)cobalt(III) complexes have been isolated and characterized by analytical and spectroscopic methods. In the former complexes, the NMR spectra indicate that the two nitrogen atoms of the coordinated 2-methyl-8-quinolinolato ligands are in the trans positions, whereas the two oxygen atoms are in the cis positions.
The Substituent Effects in Thiophene Compounds. III. 1H NMR and IR Studies in Methyl [trans-β-(Substituted 2-thienyl)acrylate]s
Authors: Satonaka Hajime 
Published: July 2006

Abstract
The 1H NMR spectra and IR C=O stretching frequencies of methyl [trans-β-(3-, 4-, and 5-substituted 2-thienyl)acrylate]s are reported. The chemical shifts of the ring protons in methyl [trans-β-(4- and 5-substituted 2-thienyl)acrylate]s are correlated linearly with those of the corresponding protons in substituted thiophenes and methyl (substituted 2-thiophenecarboxylate)s. The substituent effects on the chemical shifts of α-protons in methyl [trans-β-(3- and 5-substituted 2-thienyl)acrylate]s have been interpreted by the mesomeric effect of the substituentes. The plots of the coupling constants in methyl [trans-β-(substituted 2-thienyl)acrylate]s against those in substituted thiophenes and methyl (substituted 2-thiophenecarboxylate)s gave good linear correlations. The IR C=O stretching wave numbers showed a narrow range of variation. The coupling constants in methyl [trans-β-(substituted 2-thienyl)acrylate]s were found to vary linearly with the electronegativity of the substituents.
Regioselective Homo- and Codimerization of 1-Alkynes Leading to 2,4-Disubstituted 1-Buten-3-ynes by Catalysis of a (η5-C5Me5)2TiCl2/RMgX System
Authors: Akita Munetaka , Yasuda Hajime , Nakamura Akira 
Published: July 2006

Abstract
A series of 1-alkynes (RC≡CH where R=Et, n-Pr, n-Bu, n-C6H13, cyclohexyl, Ph, Me3Si, Me3SiCH2, and Me3SiOCH2) was found to dimerize regioselectively (&gt;99%) to 2,4-disubstituted 1-buten-3-ynes in 92–99% yields by catalysis of (η5-C5Me5)2TiCl2/i-PrMgBr at 30 °C in 1–3 h. The catalyst system is also effective for the regioselective codimerization of various 1-alkynes with 1-ethynylcyclohexene or ethynylbenzene.
Studies of the Selective Adsorption of Anions by Metal Ion Loaded Ion-exchange Resin. VI. The Adsorption Behavior of the Phosphate Ion on the Iron(III) Loaded Ion-exchange Resin
Authors: Yoshida Isao , Takeshita Ryoichi , Ueno Keihei 
Published: July 2006

Abstract
Adsorption isotherms for the phosphate ion by various iron(III)-loaded ion-exchange resins(IRC-Fe(III)), which are different in iron(III)-ion concentrations, were prepared at 5–35 °C in aqueous systems with pH values of 3 and 4.6 by means of the batch method. These isotherms could be represented by the Cp=Q∞(Cp⁄Q)−1⁄K equation in the phosphate-ion-concentration range from 3.23×10−4 to 3.23×10−2 mol dm−3 (10 ppm to 1000 ppm as P), where Cp and Q are the phosphate-ion concentrations of the aqueous phase and the adsorbent respectively; Q∞ is the saturated phosphate concentration of the adsorbent, and K is the equilibrium constant. From the analysis of adsorption isotherms, the values for Q∞ and K were determined on each adsorbent, and the nature of the adsorbent IRC-Fe(III) was discussed, with consideration paid to these two parameters and the pH-dependency of the distribution ratio of the phosphate ion between the aqueous phase and the adsorbent.
Base-induced Dehydrosulfinatocyclization of N-Alkyl-N-phenylsulfonyl-N″-arylbenzamidrazones to 3,4-Diaryl-4H-1,2,4-triazoles
Authors: Ito Suketaka , Tanaka Yumo , Kakehi Akikazu 
Published: July 2006

Abstract
3,4-Diaryl-4H-1,2,4-triazoles were obtained in good to comparable yields by the reaction of N-alkyl-N-phenylsulfonyl-N″-arylbenzamidrazones with sodium hydride. The reaction probably proceeds via the elimination of benzenesulfinic acid and the oxidative cyclization of N-alkylidene-N″-arylbenzamidrazones generated by the base-catalyzed isomerization of azo intermediates.
The Catalytic Isomerization of Butenes over a Graphite Oxide
Authors: Tsuchiya Susumu , Mikami Masahiro , Imamura Hayao 
Published: July 2006

Abstract
The relative rate constants and the activation energies of the isomerization of butenes over a graphite oxide have been measured, The reactivity of butenes and the selectivity ratios are in agreement with the characteristics of acid catalysts. The reaction profile shown on the triangular graph is of the rake-type.
Proton Chemical Shift Study of the Hydrophobic Interaction between Tris(1,10-phenanthroline)ruthenium(II) Ions in Aqueous Solutions
Authors: Masuda Yuichi , Yamatera Hideo 
Published: July 2006

Abstract
The proton NMR chemical shifts were measured in the D2O solutions of [Ru(phen)3]SO4. The proton resonances of the phenanthroline ligand showed up-field shifts with increasing concentration of [Ru(phen)3]SO4, but they were not significantly affected by the addition of Na2SO4. The profile of the up-field shifts for the Λ-[Ru(phen)3]SO4 solution was different from that for the rac-[Ru(phen)3]SO4 solution. These results prove that the up-field shifts were caused by the interaction between[Ru(phen)3]2+ ions. Assuming the formation of the triple and quadrupole aggregates containing two [Ru(phen)3]2+ ions, the association constants of these aggregates and the up-field shifts of the proton signals in the aggregates were determined. A probable structure of the aggregates was deduced from the measured chemical shifts by attributing the up-field shift in the aggregates to the ring-current effect of the phenanthroline ligand. The importance of the hydrophobic interaction between [Ru(phen)3]2+ ions in aqueous solution was thus indicated.
On the Reduction Products of Carbon Dioxide at a p-Type Gallium Phosphide Photocathode in Aqueous Electrolytes
Authors: Ito Kaname , Ikeda Shoichiro , Yoshida Makoto , Ohta Soji , Iida Takaya 
Published: July 2006

Abstract
Formic acid, formaldehyde, and methanol, previously reported as photoelectrochemical reduction products of CO2, were observed to be obtained also by photolysis of cell materials such as electrolytes and epoxy resin. The reduction product of CO2 at a p-GaP photocathode in aqueous electrolytes was experimentally confirmed to be mainly formic acid.
The Sensitization Effect in the Laser-induced Infrared Fluorescence Spectroscopy by Addition of a Second Component. III
Authors: Higuchi Seiichiro , Kagawa Yasuhiro , Tanaka Shigeyuki 
Published: July 2006

Abstract
The sensitization effect in the infrared fluorescence spectra for diethyl ether–alkene systems has been examined in terms of the quantity and the kind of alkenes added as sensitizers. The sensitivity seems to be determined by the molar ratios between diethyl ether and alkenes, and the sensitization degree lowers in an orderly fashion as the alkene molecules become larger.
Polarographic Minimum Wave of Tetraiodocadmate(II) Complex in Acetonitrile
Authors: Nagaosa Yukio , Tanaka Isao 
Published: July 2006

Abstract
Tetraiodocadmate(II) anion gives a polarographic minimum wave at potentials above −1.1 V vs. Ag/AgCl, when tetrabutylammonium iodide is used as a supporting electrolyte. The experimental results show that the minimum wave appears as a result of electrostatic repulsion between the cadmate(II) anion and the negatively charged mercury surface.
Preparation and Characterization of (l-Histidinato)(l-methioninato)cobalt(III) Bromide
Authors: Okamoto Ken-ichi , Maki Hiroko , Hidaka Jinsai 
Published: July 2006

Abstract
The (l-histidinato)(l-methioninato)cobalt(III) complex was prepared and separated into three geometrical isomers by ion-exchange chromatography. The isomers were characterized from their absorption, 1H NMR, and CD spectra.