bluuebunny/crossref_metadata_2025 huggingface dataset:
Ion-chromatographic Behavior of Silica Gels Modified by Poly- and Bis(crown ether)s of Benzo-18-crown-6
Authors: Nakajima Masaki , Kimura Keiichi , Shono Toshiyuki
Published: July 2006

Chromatographic behavior of crown ether modified silicas, in which poly- and bis(benzo-18-crown-6)s were attached covalently to silica gel, was investigated on separation of alkali and alkaline earth metal salts, using water or water/methanol as the mobile phase. Poly- and bis(benzo-18-crown-6)-modified silicas have a large affinity for Cs+, the retention time of alkali metal cations being in the order Li+<Na+<Rb+<K+<Cs+. Various anions having a common cation are separable as well as the metal cations on the modified silicas. Also, alkaline earth metal cations were separated on the stationary phases. The temperature effect of retention of alkali metal chlorides was also examined on bis(benzo-18-crown-6)-modified silica.
Restricted Rotation Involving the Tetrahedral Carbon. XLV. Appearance of a Maximum in the Rotational Barriers of 9-(1,1-Dimethyl-2-phenylethyl)triptycenes at a Medium-sized peri-Substituent
Authors: Yamamoto Gaku , Suzuki Masahiko , Oki Michinori
Published: July 2006

Rotational isomers of seven peri-substituted 9-(1,1-dimethyl-2-phenylethyl)triptycene derivatives were stereoselectively synthesized and classical kinetics on rotational isomerization were studied. While compounds with relatively small peri-substituents (F and OCH3) showed higher barriers than the peri-unsubstituted one, the peri-chloro compound had almost the same barrier with and those carrying bulkier peri-substituents (Br, CH3, and CF3) showed lower barriers than the peri-unsubstituted one. These apparently anomalous phenomena may be explained in terms of large molecular deformation of these highly congested compounds.
Response of a Copper(II) Ion-selective Electrode in Cupric Buffers Based on Macrocyclic Polyamines
Authors: Jyo Akinori , Nagamoto Akiyoshi , Khono Takashi , Ohyoshi Akira
Published: July 2006

The behavior of a copper(II) ion-selective electrode at extremely low activity levels of free copper(II) was examined in copper(II) buffers based on macrocyclic triamines([9]aneN3 and [10]aneN3) and macrocyclic tetramines ([12]aneN4, [14]aneN4, and [16]aneN4). Although the electrode showed the ideal behavior in the buffers based on [12]aneN4 and [16]aneN4, non-ideal behavior was observed for the macrocyclic triamines and [14]aneN4. Thus, the macrocyclic polyamines did not always give the ideal copper(II) buffers for the electrode, in contrast to the case of acyclic polyamines. Stability constants, which were in good agreement with the reported values, could be determined only for [12]aneN4 and [16]aneN4. An application of the cyclic tetramines to complexiometry is also presented.
Regiocontrolled Formation of 4,5-Dihydro-3(2H)-furanones from 2-Butyne-1,4-diol Derivatives. Synthesis of Bullatenone and Geiparvarin
Authors: Saimoto Hiroyuki , Hiyama Tamejiro , Nozaki Hitosi
Published: July 2006

Two new methods for selective hydration of 1,1,4-trisubstituted 2-butyne-1,4-diols (1) to give 4,5-dihydro-3(2H)-furanone derivatives are reported. The first involves selective monoacetylation of the less hindered hydroxyl group of 1 followed by Ag(I)-catalyzed rearrangement and cyclization to give 3-acetoxy-2,2,5-trisubstituted 2,5-dihydrofurans (2). Final hydrolysis yielded 2,2,5-trisubstituted 4,5-dihydro-3(2H)-furanones. Oxidation of the enol acetates 2 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone gave 3(2H)-furanones. The new method was applied to the synthesis of naturally occurring 3(2H)-furanones such as bullatenone and geiparvarin from the corresponding 2-butyne-1,4-diol derivatives. The second approach is concerned with the synthesis of the opposite regioisomer, 2,5,5-trisubstituted 4,5-dihydro-3(2H)-furanones, from diols 1 with a polymer reagent Hg/Nafion-H.
A Facile Synthesis of Colchiceine Analogues[4-(1-Acetamido-3-arylpropyl)tropolones]
Authors: Nozoe Tetsuo , Takase Kahei , Kawabe Norio , Asao Toyonobu , Yamamoto Hiroshi
Published: July 2006

The condensation of 4-acetyltropolone with various arenecarbaldehydes gave a wide variety of 4-cinnamoyltropolone derivatives in good yield. The same reaction with 2-furaldehyde and cinnamaldehyde also afforded the corresponding 4-substituted tropolones. These products were converted to their oximes (with hydroxylamine hydrochloride), which in turn were hydro genated over 5% Pd/C in acetic acid and then acetylated with acetic anhydride, to yield 4-(1-acetamido-3-aryl-2-propenyl)tropolones. The catalytic hydrogenation of these olefinic products over 10–30% Pd/C in aqueous KOH gave various 4-(1-acetamido-3-arylpropyl)tropolones,which possess a B-ring-open structure of colchiceine. The structures of these products are discussed on the basis of UV, IR, and 1H-NMR spectra.
The Sulfuranyl Radical Structure and Reactions of o-(Thio)benzoyloxyl Radicals Formed by the Decomposition of t-Butyl o-(Thio)perbenzoates Studied by 1H and 13C CIDNP and 17O NMR
Authors: Nakanishi Waro , Kusuyama Yoshiaki , Ikeda Yoshitsugu , Iwamura Hiizu
Published: July 2006

1H and 13C CIDNP signals were observed in the methyl group of o-(methylthio)benzoic acid and the methylene group of 3,1-benzoxathian-4-one (6) during the thermal decomposition of t-butyl o-(methylthio)perbenzoate. The results show that the free “o-(methylthio)benzoyloxyl radical” itself is better represented as the bridged sulfuranyl radical in which most of the spin density is localized at the sulfur atom rather than in the carboxyl. Thermolysis of t-butyl o-(methylthio)- and o-(phenylthio)perbenzoates-carbonyl-17O was carried out and the oxygen labels were detected by 17O NMR spectroscopy preferentially at the carbonyl oxygen of 6 and diphenyl 2,2′-dithiodibenzoate ruling out the zwitterionic radical structure. The migration of phenyl group and the peroxomonosulfate oxidation of o-(phenylthio)benzoic acid are also discussed.
The Formation and Thermal Decomposition of Hydrous Lead(II) Oxide Prepared by the Alkoxide Method
Authors: Narita Eiichi , Kobayashi Makito , Shinjo Hirobumi , Tsuchida Hisashi , Naito Hiroyuki
Published: July 2006

Lead(II) isopropoxide was hydrolyzed by addition to water in order to investigate the effects of temperature, rate of hydrolysis, seeds and anions added in aqueous phase on the formation of hydrous lead(II) oxide. Thermal decomposition of the resulting hydrous lead(II) oxide was also investigated using TG and DTA techniques. It was found that the metastable phase of lead(II) oxide, 3PbO·H2O (tetragonal), was formed only under certain strict conditions, i.e., at higher rate of hydrolysis and at temperatures below 40 °C, whereas the anhydrous lead(II) oxides such as massicot (orthorhombic), litharge (tetragonal), or a mixture of the two were formed under conditions other than those described above. In the presence of massicot seed in aqueous phase, massicot was predominantly formed under the formation conditions of 3PbO·H2O. It was also found that the presence of anions such as citrate and EDTA ions, which have higher complexing ability with PbII ion, facilitated the formation of 3PbO·H2O even under the formation conditions of massicot. In the heating process, 3PbO·H2O was changed to litharge at 168 °C with the release of its water of crystallization and then transformed to massicot at 650 °C. The reaction order and activation energy for the dehydration were 0.9 and 112.6 kJ mol−1, respectively.
Polarographic Studies on Mixed Ligand Complexes of Cadmium with Dl-3-(3,4-Dihydroxyphenyl)alanine and Some Dicarboxylic Acids
Authors: Gupta Nishi , Chandel Chandra Pal Singh , Gupta Prakash Chandra , Gupta Chand Mal
Published: July 2006

The reductiou of Cd(II) has been carried out polarographically in the aqueous solution of Dl-3-(3,4-dihydroxyphenyl)alanine(DOPA). The stability constants were determined for the simple Cd–DOPA system first, and then mixed-ligand complexes of cadmium with DOPA and dicarboxylic acids (oxalic and malic) have been studied. The stability constants of mixed-ligand complexes have been evaluated by the method of Schaap and McMasters. With these data the statistical and electrostatic effects have also been considered.
Partial Reduction of Dinitroarenes to Nitroanilines with Hydrazine Hydrate
Authors: Ayyangar Nagaraj R , Kalkote Uttam R , Lugade Ananda G , Nikrad Pandurang V , Sharma Vasant K
Published: July 2006

Dinitroarenes containing substituents such as hydroxyl and amine groups could be conveniently reduced with 3 molar equivalents of hydrazine hydrate in presence of Raney nickel catalyst in ethanol/1,2-dichloroethane solvent mixture to give a product wherein one of the two nitro groups was reduced to the amino group. The yields of the partial reduction products are good. Under similar conditions alkoxyl substituents in the o,p-position to the nitro groups were displaced by the hydrazino group to give 2,4-dinitrophenylhydrazine as the main product. The details of the reduction reaction are described.
Synthesis and Properties of Crown Compounds Containing Anthraquinone Nuclei
Authors: Nakatsuji Shin’ichi , Ohmori Yuko , Iyoda Masahiko , Nakashima Kenichiro , Akiyama Shuzo
Published: July 2006

2,5,8,20,23,26-Hexaoxa[7.7]-and 2,5,8,11,23,26,29,32-Octaoxa[10.10](1,8)anthraquinonophanes (2 and 3) were synthesized, examined for complexation behavior with alkali and alkaline earth metal cations, and observed to show significant selectivity among the cations studied. The electroreduction of 2 by cyclic voltammetry was studied with there lated compounds.
Synthesis of Cyclic Guanidines Fused with Aromatic Ring through Metal Ion Promoted Cyclization
Authors: Obase Hiroyuki , Nakamizo Nobuhiro , Takai Haruki , Teranishi Masayuki
Published: July 2006

A convenient synthetic method of five- and six- membered cyclic guanidines fused with aromatic ring was presented. 2-Aminoaniline or 2-(aminomethyl)aniline was treated with dimethyl carbonimidodithioates to give isothiourea which was cyclized to cyclic guanidine by using soft metal cations (Ag+, Hg2+).
A Kinetic Study on Denitration of 9,9′-Dinitro-9,9′-bifluorenyl by Tin(II) Chloride in N,N-Dimethylformamide
Authors: Fukunaga Kimitoshi , Kimura Makoto
Published: July 2006

The kinetics of the reductive elimination of nitro groups from 9,9′-dinitro-9,9′-bifluorenyl by tin(II) chloride in N,N-dimethylformamide (DMF) at 20 °C was investigated. It was found that the present elimination is a second-order reaction.
Studies on Bile Salt Solutions. Part 2. Acid Catalyzed Hydrolysis of Trimethyl Orthobenzoate in Solutions of Glycine and Taurine Conjugated Bile Salts
Authors: O’Connor Charmian J , Ch’ng Beng Tatt
Published: July 2006

The reactivity of trimethyl or thobenzoate has been studied, at 310.5 K, in solutions of the glycine and taurine conjugates of the cholanic acids. The rate-concentration profiles are characterized by peaks and troughs which coincide with discontinuities in the slopes of the surface tension-concentration profiles.
Decomposition of 2-Butanol Catalyzed by Iron Oxide and Mixed Oxides Containing Iron
Authors: Jin Tuo , Hattori Hideshi , Tanabe Kozo
Published: July 2006

Three types of binary oxides, Fe2O–TiO2, Fe2O3–ZrO2, and Fe2O3–ZnO, were prepared by a coprecipitation method, and their catalytic behaviors in the decomposition of 2-butanol were examined. The activities and selectivities of the catalysts varied with the type of the oxide with which Fe2O3 was combined, with the content of Fe2O3 in the binary oxides, and with the reduction temperature of the catalysts. Over the Fe2O3–TiO2 catalysts, 2-butanol underwent primarily dehydration and the activity decreased with an increase in Fe2O3 content. Over the Fe2O3–ZnO catalysts, dehydrogenation preferentially occurred, the maximum activity being observed for the catalyst containing 67% Fe2O3. The Fe2O3–ZrO2 catalysts exhibited an intermediate nature between the Fe2O3–TiO2 catalysts and Fe2O3–ZnO catalysts. Reduction of catalysts tended to increase the dehydrogenation selectivity. Reduction also brought about the formation of butane. The maximum formation of butane was observed when the catalysts were reduced with hydrogen at about 350–400 °C. The reaction mechanisms of the formation of butane were elucidated by tracer experiments, and it was concluded that butane was formed by the mechanism involving the first order nucleophilic substitution (SN1) of OH− by H− which was liberated in the dehydrogenation of butanols.
Adsorption of Dodecyltrimethylammonium Chloride-Decylammonium Chloride Mixtures at Water/Air Interface
Authors: Uryu Shozo , Aratono Makoto , Yamanaka Michio , Motomura Kinsi , Matuura Ryohei
Published: July 2006

The surface tension of the aqueous solution of dodecyltrimethylammonium chloride and decylammonium chloride mixture has been measured as a function of the total concentration and composition of the surfactants at 298.15 K under atmospheric pressure. It has been observed that the surface tension decreases with an increase in the composition of dodecyltrimethylammonium chloride at a fixed total concentration. A break point has been observed on the surface tension vs. total concentration curve. By applying the thermodynamic relations, the surface densities of surfactants have been evaluated numerically. It has been proved that the phase transition of the mixed adsorbed film takes place from a gaseous to an expanded state at the break point. By comparing the composition in the adsorbed film with that in the bulk phase, the difference between the compositions has been found to diminish as the surface tension decreases. It has been shown that the mutual relation between the compositions of the gaseous and expanded films at the transition point is described by the two-dimensional phase diagram.
Synthesis and Optical Resolution of [RhIII(S)3(N)3] Type Complexes Containing a Thiolato, Sulfenato, or Sulfinato Donor Group
Authors: Kita Masakazu , Yamanari Kazuaki , Shimura Yoichi
Published: July 2006

Rhodium(III) complexes, [Rh(SCH2CH2NH2)3] and [Rh{S(O)CH2CH2NH2}n{S(O)2CH2CH2NH2}3−n](n=3, 2, 1, and 0), were prepared and optically resolved by means of column chromatography or preferential crystallization of diastereomeric molecular compound with (R,R)-tartaric acid, d-C4H6O6·(−)300CD-[Rh{S(O)CH2CH2NH2}3]·H2O or d-C4H6O6·(+)300CD-[Rh{S(O)CH2CH2NH2}2{S(O)2CH2CH2NH2}]. All the present complexes have only the fac(S) geometry. The (R) configuration of sulfenato group is more stable than the (S) one in the Λ-isomer.
Kinetics of the Thermal Decomposition of Nickel Sulfate
Authors: Onuki Kaoru , Shimizu Saburo , Nakajima Hayato , Ikezoe Yasumasa , Sato Shoichi
Published: July 2006

The rate of thermal decomposition of nickel sulfate was measured in the temperature range from 1003 K to 1078 K. When a powder sample was used, this reaction was characterized as a contracting volume reaction, with apparent activation energy of 296 kJ mol−1. The gaseous products were sulfur trioxide, sulfur dioxide, and oxygen. The composition of the gaseous products was near equilibrium in regard to the reaction, SO3=SO2+1/2 O2, because the nickel oxide formed had high catalytic activity for this reaction.
The Substituent Effects in Thiophene Compounds. II. 1H NMR and IR Studies in Methyl (Substituted 3-Thiophenecarboxylate)s
Authors: Satonaka Hajime
Published: July 2006

The 1H NMR spectra and the IR carbonyl stretching frequencies of methyl (2-, 4-, and 5-substituted 3-thiophenecarboxylate)s are reported. Good linear correlation between the chemical shifts of the ring protons in methyl (5-substituted 3-thiophenecarboxylate)s and those of the corresponding protons in substituted thiophenes was observed. It was found that in methyl (2- and 4-substituted 3-thiophenecarboxylate)s, which have the carbonyl or nitro group in an ortho position, the chemical shifts for the ring protons were considerable affected by the conformation of carbonyl group, the steric hindrance, and the intramolecular hydrogen bonding. Some of methyl (ortho-substituted 3-thiophenecarboxylate)s showed the two C=O stretching bands. They were assigned to anti-s-trans and syn-s-trans forms. The substitutent effects in the C=O frequencies are also discussed. The coupling constants between ring protons of methyl (substituted 3-thiophenecarboxylate)s were correlated very closely with the corresponding ones in substituted thiophenes. The coupling constants in methyl 3-thiophenecarboxylate series were found to vary linearly with the sum of the electronegativities of the substituent on the ring.
Photorearrangements of Some Methyl-substituted Cholest-5-en-3β-ol Nitrites
Authors: Suginome Hiroshi , Maeda Norio , Kaji Makoto , Takakuwa Kyohei
Published: July 2006

Photolysis of 6-methylcholest-5-en-3β-ol nitrite and 4,4,6-trimethylcholest-5-en-3β-ol nitrite in benzene with monochromatic light respectively gave a seven-membered cyclic hydroxamic acid arising from rearrangement albeit in low yields. Photolysis of 3α-methylcholest-5-en-3β-ol nitrite and 3α,4,4-trimethylcholest-5-en-3β-ol nitrite respectively gave a nitroso dimer arising from β-scission.
An X-Ray Crystallographic Study on the Absolute Configuration of Dihydroyashabushiketol and the Solvent-dependence of Its Optical Rotation
Authors: Suga Takayuki , Ohta Shinji , Aoki Tadashi , Hirata Toshifumi
Published: July 2006

The absolute configuration of dihydroyashabushiketol was established to be S on the basis of the X-ray crystallographic analysis of the 4′,4″-dibromo derivative. In addition, it was found that the sense of the optical rotations of dihydroyashabushiketol and its dibromo derivative is determined by the interaction of their C-5 hydroxyl group with the solvent used for the measurements.
Studies of Collectors. V. The Preparation of Amidoxime-type Surfactants and the Flotation of a Trace Amount of Uranium
Authors: Koide Yoshifumi , Takamoto Hiroaki , Matsukawa Katsunori , Yamada Kimiho
Published: July 2006

This study investigates the flotation of uranium with four amidoxime-type surfactants (R12Ax, R16Ax, Ls8.6Ax, and Ls7.2Ax6.0Hx). Ls7.2Ax6.0Hx was prepared by the telomerization of acrylonitrile and acrylamide using 1-dodecanethiol as a solvent, followed by treatment with hydroxylamine. Uranium could be floated effectively at pH 5.0 with R12Ax, R16Ax, or a combination of Ls8.6Ax and a nonionic surfactant. The floatability for uranium present in sea water was 43% after the addition of 1 mg R16Ax and 90% after the addition of 30 mg R12Ax. Ls7.2Ax6.0Hx formed a soluble complex, and 72% of the uranium present in sea water could be collected at pH 8.0 by foam fractionation using Ls7.2Ax6.0Hx. Little surfactant remained in the residual solution, and it was regenerated from an acidic solution dissolving the scum or froth.
Studies on Thermodynamics for the Hydrolysis. II. The Temperature Effect on the Stereoselective Deacylation of Amino Acid Esters in Bilayer and Micellar Systems
Authors: Matsumoto Y\={o}ko , Ueoka Ryuichi
Published: July 2006

Stereoselective deacylations of p-nitrophenyl N-acyl-d(or l)-phenylalaninates(d(or l)-Sn; n=2, 12, and 16) and N-benzyloxycarbonyl-d(l)-phenylalaninates(d(l)-ZS) by the bilayer and micellar catalytic systems of l-histidine derivatives (LauHis, MyrHis, PalHis, LauHisLeu, and MyrHisLeu) and surfactants (2CmN2C1Br with m=12, 14, and 16, CTAB, OTAC, and (R)-(+)-SUR16) were performed. It is noteworthy that the temperature dependence of enantioselectivity for the deacylation of S12 having a long acyl chain is bell-shaped with maxima at 25 °C and 15–25 °C in the bilayer systems of MyrHis+2C12N2C1Br and MyrHisLeu+2C12N2C1Br, respectively. On the other hand, the enantioselectivity for the S12 deacylation catalyzed by LauHisLeu in the presence of the CTAB micelles increases as temperature is lowered (the highest enantiomer rate ratio (kLa,obsd⁄kDa,obsd=12) is attained at 20 °C). The enantioselectivity for the deacylation of S2 having a short acyl chain, however, is almost constant and considerably lowered in comparison with that for the deacylation of S12 in both the bilayer and micellar systems. According to the isokinetic temperature (β), the deacylation of Sn (n=2 and 12) and ZS in the bilayer systems might be entropy-driven, whereas that in the micellar systems might be enthalpy-driven. The stronger hydrophobic microenvironment of the bilayer systems in the ester-deacylation would probably be connected with the entropy-driven nature.
Band-structure Parameters of Organic Conductors, TSeT2Cl, TTT2I3, and TSeT2SCN
Authors: Mori Takehiko , Kobayashi Akiko , Sasaki Yukiyoshi , Kobayashi Hayao
Published: July 2006

The band-structure parameters of organic conductors, TSeT2Cl, TTT2I3, and TSeT2SCN (TSeT; 5,6: 11,12-bis(diseleno)naphthacene; common name: tetraselenotetracene, and TTT; 5,6:11,12-bis(dithio)naphthacene; common name: tetrathiotetracene) were calculated using semiempirical molecular-orbital calculations. The longitudinal bandwidth W and the anisotropy parameter α of TSeT2Cl were obtained as 0.6 eV and 0.188 respectively. The shape of the Fermi surface, as calculated from the tight-binding theory and the large anisotropy parameter, agrees with its semimetallic nature at low temperatures. In TTT2I3, W=0.56 eV, and α=0.018. This compound was regarded as a one-dimensional metal. The semiconductive conduction of TSeT2SCN was interpreted in terms of the small bandwidth, W=0.26 eV.
Alizarin Red-S, an Amperometric Reagent for Ultramicro and Microgram Estimation of Sm3+ and Gd3+
Authors: Lavale S C , Pitre K S
Published: July 2006

Alizarin Red-S has been employed successfully as an amperometric reagent for the precise determination of Sm3+ and Gd3+ in aqueous and partially non aqueous media. Amperometric titrations have been performed at −0.7 V vs. Hg-pool, pH=4.5 and μ=0.1. The current-volume titration curves obtained were well defined, indicating 1:2 stoichiometric ratio of metal:ARS complexation in each case. The absorptiometric studies made on the equilibrium of above complexation also confirm the said ratio. Many ions do not interfere the titration procedure.
Liquid-Liquid Distribution of 4-Acyl-3-methyl-1-phenyl-5-pyrazolones and Their Zinc Complexes
Authors: Umetani Shigeo , Matsui Masakazu
Published: July 2006

The distribution of eight 4-acyl-3-methyl-1-phenyl-5-pyrazolones and their zinc complexes between aqueous and cyclohexane phases was investigated. The acid dissociation constants and partition constants of the extractants were discussed in terms of a substituent effect. It was found that two series of examined reagents in which one has an aromatic substituent at the 4-position of 5-pyrazolone, and the other an aliphatic one give similar extraction constants. Since their acid dissociation constants are essentially the same, a relationship, logPMA=2logPHA+ constant, is postulated. The extraction constant of a fluorinated reagent which has a considerably small pKa value is also similar to that of the reagents having aliphatic substituents. Another relationship, logβ2=2pKa+ constant, is postulated.
Infrared ATR Measurements at Low Temperatures. An Apparatus and the Absorption Intensities of Crystalline Benzene and Carbon Disulfide
Authors: Yamada Haruka , Saheki Masao
Published: July 2006

An infrared ATR apparatus for use at low temperatures was constructed for the determination of the optical constants and absorption intensities of crystalline samples. The ATR spectra of benzene and carbon disulfide polycrystals were measured with two different incident angles. The optical constants and then the absorption intensities were accurately obtained for the fundamental bands from these ATR spectra. Experiments for transmission spectra were also carried out with an improved absorption cell at low temperatures, confirming the present ATR results. A comparison of the intensities in different phases was made for the ν18, ν19, ν20, and ν11 fundamental bands of benzene and the ν3 band of carbon disulfide.
Use of an Ion-selective Electrode as a Detector in Ion Pair Chromatography
Authors: Jyo Akinori , Mori Kenji , Ishibashi Nobuhiko
Published: July 2006

A chloride ion-selective electrode was used as a detector for inorganic anions separated by ion pair chromatography. Excellent performance of the electrode detector was demonstrated by detection of chloride, iodide, and thiocyanate.
Determination of Small Amounts of Carbazole in Anthracene by Synchronous Fluorescence Spectrometry
Authors: Furusawa Motohisa , Tachibana Masaki , Fujishima Mamiko
Published: July 2006

After converting anthracene into the Diels-Alder adduct by the reaction with maleic anhydride, and converting the adduct into a water-soluble salt by hydrolysis with potassium hydroxide aqueous solution, carbazole is then extracted into 2,2,4-trimethylpentane together with other impurities. Then carbazole can be determined by synchronous fluorescence spectrometry without interference of the impurities.
Photochemical Synthesis of the Acetylene Adducts and Dimers of 2H- and 4H-1-Benzopyranones
Authors: Matsui Takanao , Nakayama Mitsuru
Published: July 2006

7-Methoxychromone reacts photochemically with acetylene to form 5-methoxy-2a,8a-dihydro-8H-banzo[b]cyclobuta[e]pyran-8-one and its valence isomer. Photoaddition of acetylene to 6-methoxychromone and 7-methoxy-4-methylcoumarin did not proceed, but the latter underwent photodimerization to give the head-to-tail dimers.
Preparation of Sydnone-4-carboxamide Oximes and Their Conversion into 4-(1,2,4-Oxadiazol-3-yl)sydnones
Authors: Yeh Mou-Yung , Nonaka Tsutomu , Goto Takushi , Hsu Ming-Ching , Fuchigami Toshio , Tien Hsien-Ju
Published: July 2006

3-Arylsydnone-4-carboxamide oximes (2) were prepared from the corresponding 3-arylsydnone-4-carbonitriles and hydroxylamine in high yields. The amide oximes 2 reacted with orthoesters to give 3-aryl-4-(1,2,4-oxadiazol-3-yl)sydnones.
The Configurations of N-Methyl- and N-t-Butyl-α-methoxycarbonylmethanimine N-Oxides
Authors: Inouye Yoshinobu , Takaya Kazuharu , Kakisawa Hiroshi
Published: July 2006

N-Methyl-α-methoxycarbonylmethanimine N-oxide, Z configuration in crystal, was found to exhibit a facile equilibration with its E-isomer in solution. The configuration of N-t-butyl derivative was always Z.
Viscosity B-Coefficients, Apparent Molar Volumes, and Activity Coefficients for α- and γ-Cyclodextrins in Aqueous Solutions
Authors: Miyajima Koichiro , Sawada Masahiro , Nakagaki Masayuki
Published: July 2006

The viscosities and densities at 15, 25, and 35 °C, and activity coefficients at 25 °C for the aqueous solutions of α- and γ-cyclodextrins were measured, and the results were interpreted in terms of solute-solvent and solute-solute interactions. The concentration and temperature dependences of viscosities and apparent molar volumes are almost similar to those of linear saccharides, i.e. maltose and maltotriose, indicating that α- and γ-cyclodextrins are structure forming solutes. However, the concentration dependences of activity coefficients of cyclodextrins are significantly different from those of maltose and maltotriose. The results were tentatively assigned to the formation of dimer in aqueous solutions.
Spectrophotometric Determination of Ruthenium(III) and Rhodium(III) with 9,10-Phenanthrenequinone Monoxime after Extraction into Molten Naphthalene
Authors: Wasey Abdul , Bansal Raj K , Satake Masatada , Puri Bal K
Published: July 2006

9,10-Phenanthrenequinone monoxime has been used as a reagent for the spectrophotometric determination of ruthenium(III) and rhodium(III) after extraction into molten naphthalene. The extracted mixture of the metal complex and naphthalene was dissolved in chloroform and ruthenium and rhodium were determined spectrophotometrically. Beer’s law holds in the concentration range of 0.2–4.1 μg/cm3 for ruthenium and 0.3–5.3 μg/cm3 for rhodium in 10 cm3 of the final solution. The molar absorptivities and Sandell sensitivities are calculated to be 9.70×103 l mol−1 cm−1 and 0.01 μg/cm2 (660 nm) for ruthenium and 1.13×104 l mol−1 cm−1 and 0.009 μg/cm2 (410 nm) for rhodium respectively. Aliquots containing 2.0 μg of ruthenium and 4.1 μg of rhodium give mean absorbances of 0.192 and 0.451 with standard deviations of 0.0017 and 0.0039, respectively. Interference of various ions has been studied and the method has been applied to the determination of ruthenium and rhodium in various synthetic mixtures. This procedure is also applied to the simultaneous determination of ruthenium and rhodium present together in a solution.
The Stereochemistry and Reactivity of Metal-Schiff Base Complexes. VI. The Kinetics and Mechanism of Isomerization between ΔL-β2- and ΛL-β2-Diastereoisomers of N,N′-Ethylenebis(α-methylsalicylideneaminato)cobalt(III) Complexes with l-Amino Acid
Authors: Fujii Yuki , Kobayashi Takemaru , Matsufuru Makoto , Takahashi Sozo
Published: July 2006

The kinetics for isomerization between ΔL-β2- and ΛL-β2-diastereoisomers of [Co(α-Me-sal2en)(l-aa)], where l-aa represents l-phe, l-met, l-ile, l-pro, N-Bz–l-ala, and N-Me–l-ala, were studied in methanol. The activation enthalpies (ΔH\eweq/kJ mol−1) and the activation entropies (ΔS\eweq/J K−1 mol−1) from the ΔL-β2-isomer (unstable form) to the ΛL-β2-isomer (stable form) were determined to be 86.6 and −9.6 for l-phe, 92.5 and +6.7 for l-met, 87.5 and −8.0 for l-ile, 100.4 and +28.0 for N-Bz-l-ala, and 102.9 and +18.4 for N-Me-l-ala, respectively. For l-procomplex, the ΔL-β2-isomer is the stable form, and the enthalpy and entropy for isomerization from ΛL-β2- to ΔL-β2- isomers were 96.2 and 0.0. The isomerization was catalyzed by acids but not by bases, and was much faster than the substitution of coordinated l-amino acid. The H–D exchange of N–H proton of N-Me–l-ala-complex proceeded with almost the same rate as the isomerization. The isomerization showed strong solvent dependency; it was fast in a hydrogen-bonding solvent, but was quite slow in a weak- or nonhydrogen-bonding solvent. On the basis of these facts, proton-assisted and/or hydrogen-bonding solvent-assisted intramolecular mechanism via an intermediate is proposed, in which the Schiff base takes a planar configuration and the amino acid coordinates as a unidentate ligand with its carboxylate group.
Synthesis of Lactone-opened Derivatives of anti and syn Head-to-Head Coumarin Dimers
Authors: Yonezawa Noriyuki , Hasegawa Masaki
Published: July 2006

anti and syn Head-to-head coumarin dimers reacted readily with amines and alcohols to give the corresponding diamides, diesters, imides, or the monoactone derivatives.
Electron Spin Resonance Study of X-Irradiated Single Crystals of Silver(I) Nitrate–Butanedinitrile(1/1)
Authors: Kurita Yukio , Ohigashi Hiroji
Published: July 2006

ESR spectra of single crystals of silver(I) nitrate–butanedinitrile(1/1) were measured at 77 K. Two paramagnetic centers, –CN···Ag2+···NC– and NO32−···Ag+, appeared simultaneously on X-irradiation at 77 K. The principal values of the g value (g) and the hyperfine coupling constants (A in the units of 10−1 cm−4) were g1=2.050, g2=2.053, and g3=2.302, A(Ag)1=21.8, A(Ag)2=22.0, A(Ag)3=34.9, A(N)1=15.3, A(N)2=15.9, and A(N)3=14.0 for the first center, and g⁄⁄=2.001, g⊥=2.006, A(Ag)⁄⁄=20.3, A(Ag)⊥=17.4, A(N)⁄⁄=59.4, and A(N)⊥=32.8 for the second center. When the crystals X-irradiated at 77 K were exposed to visible light, the two centers disappeared simultaneously and the NO2 radicals increased. When the crystals X-irradiated at 77 K were warmed to room temperature, the first center changed to a new paramagnetic center, in which the unpaired electron coupled with a silver nucleus, two equivalent nitrogen nuclei, and a proton.
Studies of Polystyrene-based Ion Exchange Fiber. I. The Preparation and Fundamental Characteristics of Polystyrene-based Ion Exchange Fiber
Authors: Yoshioka Toshio , Shimamura Masaharu
Published: July 2006

A polystyrene-based ion exchange fiber which has a large ion exchange capacity (ca. 2.5 mequiv g−1) and a high mechanical strength (ca. 1.4 g d−1) has first been prepared by using an islands-in-a-sea type composite fiber, the sea ingredient predominantly comprised of polystyrene for ion exchange and the island ingredient comprised of fiber-forming polypropylene for reinforcement, as the starting material; it can be used in an arbitrary form. It was found that the resulting fiber has two fundamental characteristics; the ion exchange rate for metal ions is extremely high, and the capacity of adsorbing the macromolecular ionic substance is exceedingly large, compared with ordinary ion exchange resins. The diffusion equation of ion exchange in the case of a cylindrical, endless fiber was solved by a modification of the method used for a spherical resin in a simple system. The former results are interpreted in terms of their solutions for two limiting cases. The latter results are explained by the fact that the surface-area ratio of the fiber to the resin is about ten.
The X-Ray and NMR Studies on the Regio- and Stereoselective Courses for Insertion of Ketones into the s-cis- and s-trans-Diene Complexes of Zirconium Leading to (Z)-1,2-Oxazirconacyclohept-4-enes
Authors: Kai Yasushi , Kanehisa Nobuko , Miki Kunio , Kasai Nobutami , Akita Munetaka , Yasuda Hajime , Nakamura Akira
Published: July 2006

The s-trans-diene coordination in (η5-C5Me5)2Zr(butadiene) and the s-cis-diene coordination in (η5-C5Me5)2Zr(isoprene) were confirmed by the 1H- and 13C-NMR spectral studies. The reaction of 2,4-dimethyl-3-pentanone with these complexes occurred regio- and stereoselectively to give (Remark: Graphics omitted.) (5: R=H, 6: R=Me). The X-ray crystal structure analysis of 5 and 6 revealed the (Z)-configuration with respect to the olefin part. Crystal data for 5: monoclinic, space group P21/n with Z=4, a=11.650(2), b=17.791(3), c=13.612(2) Å, β=92.20(2)°, R=0.111 for 4308 non-zero reflections. Crystal data for 6: monoclinic, space group P21/n with Z=4, a=10.279(3), b=30.177(4), c=9.955(2) Å, β=108.67(2), R=0.104 for 3526 non-zero reflections.
Racemization of Optically Active Amino Acid Salts and an Approach to Asymmetric Transformation of Dl-Amino Acids
Authors: Hongo Chikara , Yoshioka Ryuzo , Tohyama Masanori , Yamada Shigeki , Chibata Ichiro
Published: July 2006

In connection with optical resolution of Dl-amino acids, the racemization process of optically active amino acid salts was studied. A wide variety of salts of optically active amino acids with sulfonic acids or mineral acids could be racemized by heating in a medium of acetic acid at 80–100 °C for 1 h in the presence of 0.1 molar equivalents of an aldehyde and free Dl-amino acid. From the reaction mixture, the racemized Dl-amino acid salts were recovered in high yield (86–92%) and in high purity. An asymmetric transformation between two enantiomers of amino acid salt was attempted by the combination of preferential crystallization of the desired enantiomer and racemization of the antipode in the liquid phase. Dl-Alanine p-chlorobenzenesulfonate was partially converted to l-isomer (yield 16%, optically purity 97%). Another approach was carried out by transformation between two diastereoisomeric salts. The combination of selective precipitation of less soluble diastereoisomeric salt and epimerization of soluble diastereoisomeric salt allowed Dl-phenylglycine d-camphor-10-sulfonate to be partially converted to d-phenylglycine d-camphor-10-sulfonate (yield 68%, optical purity 96%).
Tetraammineplatinum(II)–Hydrogen Ion Exchange on α-Zirconium Phosphate and the Characterization of Its Complex Cation Form
Authors: Hasegawa Yoshitsugu , Yamamine Giichi
Published: July 2006

The tetraammineplatinum(II)–hydrogen-ion exchange on α-zirconium phosphate has been investigated. The ion-exchange process was examined by measuring the change in the pH values of the supernatants. α-Zirconium phosphate loaded with tetraammineplatinum(II) was characterized by means of chemical analysis, X-ray diffractometry, infrared spectroscopy, and thermal analysis. The ion-exchange reaction proceeded more easily than the hexaaminecobalt(III)–hydrogen-ion exchange, and about 50% of the hydrogen ions in α-zirconium phosphate were replaced by tetraammineplatinum(II). The interlayer distance of the exchanger expanded from 7.60 to 10.7 Å.
Reduction of Macrocyclic Cobalt(III) Complex Photosensitized by Tris(2,2′-bipyridine)ruthenium(II)
Authors: Kurimura Yoshimi , Endo Emiko
Published: July 2006

The photosensitized reduction of macrocyclic cobalt(III) complex, [Co(N4)(OH2)2]3+ (N4=Me6[14]4,11-dieneN4), occurs rapidly in an anaerobic [Ru(bpy)3]2+/[Co(N4)(OH2)2]3+/triethanolamine solution. The mechanistic implications of the photosensitized reaction are discussed.
Succinate-complexed Octacalcium Phosphate
Authors: Monma Hideki , Goto Masaru
Published: July 2006

A succinate-complexed calcium phosphate has been synthesized by conducting the hydrolysis of α-tricalcium bis(phosphate) in the presence of succinate ions. The organic substance is considered to be introduced into the structure of the hydrolysis product, i.e., octacalcium bis(hydrogen-phosphate) tetrakis(phosphate) pentahydrate, through the replacement of HPO42− by C4H4O42−.
Absolute Configurations Assigned to Some Octahedral cis-Bis(diamine)cobalt(III) Complexes on the Basis of Their Stereoselective Interactions in Solution
Authors: Miyoshi Katsuhiko , Watanabe Kenzo , Toda Yoshihisa , Yoneda Hayami
Published: July 2006

Absolute configurations are assigned to some cationic cis-[Co(diamine)2(X)(Y)]n+-type complexes by detecting the direction of the chiral equilibrium shift induced for [Cr(ox)3]3− in the presence of these chiral complexes in water–dioxane mixtures. The assignments are found all consistent with those made earlier by CD spectra.
Coagulated Ion-exchanger Colorimetry for the Determination of Trace Amounts of Sulfide as Methylene Blue
Authors: Matsuhisa Kiichi , Ohzeki Kunio , Kambara Tomihito
Published: July 2006

Sulfide ion was converted to Methylene Blue through the reaction with N,N-dimethyl-p-phenylenediamine in the presence of iron(III) ion. The dye produced was fixed by batch method onto the coagulated mixture of finely divided anion and cation exchange resins. The coagulated material was collected by filtration on a filter paper as a disk of thin layer, which was then soaked in an acetate buffer solution, and subjected to the spectrophotometric analysis. The calibration graph was linear over the range 1.03–10.3 nmol of sulfide. The method was applied to some hot spring waters.
Cycloaddition of Diphenylcyclopropenone with Carboximidate, Carboximidamide, and Carboximidothioate
Authors: Yoshida Hiroshi , Sogame Shingo , Bando Shoichi , Nakajima Shosuke , Ogata Tsuyoshi , Matsumoto Kiyoshi
Published: July 2006

The reaction of diphenylcyclopropenone with R1N=C(R2)X (2) (R1, R2= alkyl, aryl, X=MeO, EtO, MeS, or Me2N) gave 2-pyrrolin-4-one (3) in good yield. The less reactive carboximidothioate (2, R1=4-MeC6H4, R2=Ph, X=MeS) yielded isomeric 3-pyrrolin-2-one together with 3.
Molecular Force Fields of s-trans-1,3-Butadiene and the Second Stable Conformer
Authors: Furukawa Yukio , Takeuchi Hideo , Harada Issei , Tasumi Mitsuo
Published: July 2006

Normal-coordinate analyses of s-trans-1,3-butadiene and its various deuterated and 13C-substituted analogs were performed using the group-coordinate force field, and a set of force constants was determined. The infrared spectra of the second stable conformer of 1,3-butadiene-d0, -1,1,4,4-d4, and -d6 were analyzed on the basis of normalcoordinate calculations of the planar s-cis form and a nonplanar gauche form. Such an analysis suggests that the second stable conformer takes a gauche form rather than the s-cis. To increase the number of reliable data to be used in this study, the infrared and Raman spectra of the d0, 1,1,4,4-d4, and d6 species were observed in low-temperature Ar matrices. The infrared spectra of the second stable conformer were also observed using a combination of the high-temperature nozzle and low-temperature matrix techniques.
A Model of Nematic Liquid Crystals for Viscosity and Self-diffusion
Authors: Miyajima Seiichi , Nakamura Nobuo , Chihara Hideaki
Published: July 2006

A Geometrical model is presented which rationalizes the viscosity and self-diffusion coefficients and their anisotrcpies in nematic liquid crystals. The model is an extension of Eyring’s theory of the liquid state to the anisotropic fluid, based on the geometry of the constituent molecule. A novel concept, effective anisotropy factor of a molecule, is introduced which is determined from the viscosity coefficients. An empirical law on the principal viscosity coefficients by Kneppe et al. is given its molecular basis by this model. Self-diffusion coefficient tensor calculated from the available viscosity data of PAA, MBBA, and HBAB agree well with experiment.
The Crystal and Molecular Structure of Bis(methanol)-α,β,γ,δ-tetraphenylporphinatomanganese(III) Perchlorate-Methanol. A Molecular Structure Relevant to the Intermediate-spin Six Coordinate Iron(III) Porphyrin
Authors: Hatano Keiichiro , Anzai Kazunori , Iitaka Yoichi
Published: July 2006

Bis(methanol)-α,β,γ,δ-tetraphenylporphinatomanganese(III) perchlorate crystallizes as the methanol solvate in the triclinic system, space group P\bar1, a=16.225(8), b=13.167(7), c=10.793(5) Å, α=106.51(5)°, β=100.36(5)°, γ=101.60(5)°, and Z=2. The structure was determined by the heavy-atom method and the block-diagonal least-squares refinement using a total of 9992 reflections. The final R and Rw values are 6.3 and 7.1%, respectively. Two slightly different but substantially identical coordination spheres of high-spin Mn(III) porphyrin were revealed. The long axial Mn–O(methanol) bond distance and medium-sized porphyrin core were emphasized as structural characteristics in relation to the intermediate-spin iron(III) porphyrin.
The Reaction of Sodium Nitrite with Silica
Authors: Abe Osami , Utsunomiya Taizo , Hoshino Yoshio
Published: July 2006

The reaction of sodium nitrite with silica has been investigated over the relatively wide composition range (Na/Si=0 to 10.0) below 800 °C. In an argon atmosphere, sodium nitrite reacts with oxygen to form sodium nitrate above 400 °C and decomposes to sodium oxide via other oxide species above 500 °C, irrespective of the coexistence of silica. The reaction of sodium nitrite with silica in an argon atmosphere consists of two stages. In the early stage (<600 °C), the main gaseous product is NO, while in the later stage nearly equimolar amounts of NO and O2 are formed. The early stage is further divided into two reaction processes: Process I, in which peroxide is considered to be formed in the melt by generating NO, and Process II, in which nitrate and silicates are formed by generating NO and a trace amount of O2. Peroxide is supposed to be stabilized at the solid-liquid interface, even if no silicates have been formed at relatively low temperatures. In the later stage, the reaction process or mechanism can be regarded as similar to that of sodium nitrate with silica, as the concentration of nitrite in the melt is very low.
X-Ray Diffraction Studies on the Structures of Hydrated Oxonium Ion, and the Chlorocobalt(II) and Tetrachlorocobaltate(II) Complexes in Aqueous Solutions
Authors: Lee Hyo-Gwang , Matsumoto Yukiei , Yamaguchi Toshio , Ohtaki Hitoshi
Published: July 2006

The structure of hydrated oxonium ion has been determined in a concentrated hydrochloric acid solution by the X-ray diffraction method. The oxonium ion H3O+ combines with four water molecules to form a trigonal pyramid structure in which three water molecules have an H3O+–H2O distance of 2.44 Å, while the water molecule at the apex of the pyramid is separated by 2.90 Å from the central oxygen atom of the oxonium ion. The structure of the CoCl+ determined in a relatively dilute lithium chloride solution (the Cl/Co mole ratio is 3.38) shows that the cobalt(II) ion is coordinated with five water molecules, the Co–OH2 distance being 2.14 Å. The Co–Cl distance within the complex is 2.35 Å. The CoCl42− complex has a regular tetrahedral structure both in a concentrated lithium chloride (Cl/Co=22.1) and a hydrochloric acid (Cl/Co=21.1) solutions with the Co–Cl bond length of 2.29 Å.
Studies of the Metal Complexes of Cyclohexane Derivatives. VII. Preparation and Properties of Platinum(II) and Cobalt(III) Complexes of (1R,2S)-1-Aminomethyl-2-methylcyclohexylamine
Authors: Saito Reiko , Kidani Yoshinori
Published: July 2006

Optically active (1R,2S)-1-aminomethyl-2-methylcyclohexylamine (R,S-2m-amcha) was synthesized and two Pt(II) and two types of Co(III) complexes containing this ligand were prepared. 1H-NMR and 13C-NMR spectra of the Pt(II) complexes and CD spectrum of trans-[CoCl2(R,S-2m-amcha)2]+ indicated that the chelate ring takes predominantly the λ conformation with the equatorial C1–C2 bond of the cyclohexane ring. The absolute configuration of the ligand has been assigned on the basis of the conformation of the complexes. All possible isomers of the tris Co(III) complex, fac-Δ(lel3), mer-Δ(lel3), mer-Λ(ob3), and fac-Λ(ob3), were isolated and characterized.
Synthesis of Octachlorobicyclo[3.3.0]octa-1,4,6-triene and Lewis Acid Catalyzed Isomerization of Hexachlorobicyclo[3.3.0]octa-3,5,8-trien-2-one
Authors: Kusuda Kousuke
Published: July 2006

Treatment of decachloro(4-allylidenecyclopentene) with enneacarbonyldiiron(0) gave octachlorobicyclo[3.3.0]octa-1,3,7-triene (δ-C8Cl8) in 40% yield. Dechlorination of decachlorobicyclo[3.3.0]octa-2,6-diene with powdered selenium, sulfur, phosphorus, or titanium in the presence of anhydrous aluminium chloride without any added solvent at 90–100 °C afforded octachlorobicyclo[3.3.0]octa-1,4,6-triene (2) (ε-C8Cl8) in good yield. Hexachlorobicyclo[3.3.0]octa-3,5,8-trien-2-one obtained from 2 was chlorinated by a concentrated solution of antimony(V) chloride in refluxing dichloromethane to give octachlorobicyclo[3.3.0]octa-3,6(or 7)-dien-2-one, but in a dilute solution (less than 0.1 g of antimony(V) chloride/cm3 of dichloromethane) hexachlorobicyclo[3.3.0]octa-4,6,8-trien-2-one (14) was obtained. Mechanism of the isomerization is discussed in terms of antiaromaticity of cyclopentadienyl cation. Reaction of 14 with methanol afforded pentachloro-4-methoxybicyclo[3.3.0]octa-3,5,7-trien-2-one. Ethanol or 2-propanol reacted with 14 similarly giving pentachloro-4-ethoxybicyclo[3.3.0]octa-3,5,7-trien-2 -one or pentachloro-4-isopropoxybicyclo[3.3.0]octa-3,5,7-trien-2-one, respectively.
Studies on 2-Aziridinecarboxylic Acid. IX. Convenient Synthesis of Optically Active S-Alkylcysteine, threo-S-Alkyl-β-methylcysteine, and Lanthionine Derivatives via the Ring-opening Reaction of Aziridine by Several Thiols
Authors: Nakajima Kiichiro , Oda Hitomi , Okawa Kenji
Published: July 2006

A convenient synthesis of optically active S-alkylcysteine, threo-S-Alkyl-β-methylcysteine, and lanthionine derivatives has been investigated. Benzyl 1-benzyloxycarbonyl-(2S)-2-aziridinecarboxylate and benzyl (2S,3S)-1-benzyloxycarbonyl-3-methyl-2-aziridinecarboxylate, and their enantiomers were treated with several thiols, and the corresponding S-alkylcysteine, threo-S-alkyl-β-methylcysteine, and lanthionine derivatives were prepared via the ring-opening reaction of aziridine in the presence of a catalytic amount of boron trifluoride etherate in good yields.
Pure Spectra of Actinomycin D Bound to DNA at Various Ionic Strengths Extracted by the Principal-component-analysis Method
Authors: Matsuda Takumi , Kashiramoto Saburo , Yamaoka Kiwamu
Published: July 2006

The interaction between actinomycin D (AMD) and native and heat-denatured DNA was studied spectrophotometrically at 25 °C. By applying the principal-component-analysis (PCA) method to the series of observed spectra, the number of light-absorbing components was determined. Two spectroscopically different species of bound AMD, i.e., AMD–DNA complexes, were formed when an aqueous AMD solution was titrated with either the native or the denatured DNA solution over a wide range of the nucleotide residue-to-AMD mixing ratios (P/D) between 0 and 30. The pure spectra of AMD bound to DNA were extracted in the P/D range 0–4 by the extended PCA method with an appropriate binding scheme. These bound-AMD spectra were affected by the DNA conformation but not by the addition of NaCl (1–500 mmol dm−3). The fractions of bound AMD were calculated as a function of P/D.