bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactivities of Stable Rotamers. XIX. Basicities of Rotameric 9-[2-(Dialkylaminomethyl)-6-methylphenyl]fluorenes and Solvent Effects on Them
Authors: Nakamura Mikio , Oki Michinori 
Published: July 2006

Abstract
The pKa′ values of the trifluoroacetate salts of the title compounds were determined in THF–water (3:2) solution at 25 °C by potentiometric titration: in every compound examined, basicity of the ap rotamer was higher than that of the sp rotamer. Differences in pKa′ values (ΔpKa) between the rotamers are in the range of 0.55 to 1.14 pKa units, depending upon the substituents on the nitrogen atom. The ΔpKa values in chloroform-d solution at 80.1 °C determined by taking advantage of the equilibrium constants of the salts and the free amines were larger than those obtained in aqueous THF solutions and were nearly independent of the substituents. The results were explained in terms of the intramolecular NH-π interactions in the ap salts, which are not possible in the sp. 1H and 13C NMR spectral data were in conformity with the presence of the interactions. Examination of the population ratios in various solvents revealed that sp conformers of the free amines are generally favored over the ap in polar, proton-accepting solvents, but the reverse is true for the trifluoroacetate salts. As the results, ΔpKa values are large in toluene and chloroform but are rather small in tetrahydrofuran, acetonitrile, and nitromethane. Possible causes for the differences including solvation and hydrogen bond formation are discussed.
Synthesis of 2,6-Dimethyl-6-(8-methyl-4-methylene-7-nonenyl)-2-cyclohexene-1-methanols from α-Santonin
Authors: Nagano Hajime , Masunaga Yukari , Matsuo Yukiko , Shiota Michio 
Published: July 2006

Abstract
α-Santonin was converted to 2,6-dimethyl-6-(8-methyl-4-methylene-7-nonenyl)-2-cyclohexene-1-methanols (1a and 1b). Both spectral data of 1a and 1b were found to be different from those reported for magydar-2,10(20),13-trien-17-ol, a diterpene isolated from Magydaris panacifolia (Vahl) Lange. This indicates that the structure of the natural diterpene should be revised; the structure was later revised to t-6-hydroxymethyl-1, t-3-dimethyl-t-2-(3-methyl-2-butenyl)-3-(4-methyl-3-pentenyl)-r-1-cyclohexanol.
27Al High-Resolusion Solid-State NMR Study of Hydration of Ultrafine Powder of Aluminum Nitride
Authors: Hayashi Shigenobu , Hayamizu Kikuko , Yamamoto Osamu 
Published: July 2006

Abstract
27Al NMR spectra of hydrated aluminum nitride ultafine powder, measured using magic angle sample spinning technique, showed two peaks which can be attributed to Al coordinated by four N atoms and to Al coordinated by six O atoms, and the hydration process was discussed.
Double Inclusion of Methylated Cyclodextrin and Sodium Benzenesulfonate by Na–, Ca–, and Cu–Montmorillonites
Authors: Kijima Tsuyoshi 
Published: July 2006

Abstract
The uptake of methylated α- and β-cyclodextrins by Na–, Ca–, and Cu–montmorillonites at 25 °C in the presence of sodium benzenesulfonate has been studied. X-Ray diffraction data revealed that the cyclodextrin molecules that embrace benzenesulfonate anion are intercalated as monolayer in the interlayer space of the clay minerals.
Microscopic and Dielectric Studies of CH3NH3I Crystal
Authors: Yamamuro Osamu , Oguni Masaharu , Suga Hiroshi 
Published: July 2006

Abstract
Observation of CH3NH3I crystal under a polarizing microscope showed a rectangular domain structure in the δ phase. Dielectric measurement revealed an antiferroelectric behavior of the same phase. These results indicate that the δ phase has orthorhombic or monoclinic structure with C–N axes of CH3NH3+ ions inclining along its a or b axis in an antiferroelectric way.
The Steam Stability of H-ZSM-5-Type Zeolites Containing Alkaline Earth Metals
Authors: Fujisawa Kazuyoshi , Sano Tsuneji , Suzuki Kunio , Okado Hideo , Kawamura Kichinari , Kohtoku Yasuhiko , Shin Shigemitsu , Hagiwara Hiroyuki , Takaya Haruo 
Published: July 2006

Abstract
The steam stability of H-ZSM-5-type zeolites containing alkaline earth metals was investigated by means of 27Al MASNMR, the TPD of NH3, and methanol conversion reactions. It was found that the steam stability of the H-ZSM-5-type zeolites is greatly improved by adding alkaline earth metals.
Conversion of β-Senepoxide to Crotepoxide: Total Synthesis of (+)-Crotepoxide
Authors: Ogawa Seiichiro , Takagaki Tohei 
Published: July 2006

Abstract
Total synthesis of (+)-crotepoxide has been accomplished by chemical conversion of (+)-β-senepoxide which was prepared from (−)-7-endo-oxabicyclo[2.2.1]hept-5-ene-2-carboxylic acid.
Synthesis and Biological Activity of Substance P Analogs Containing Pyrohomoglutamic Acid and Homoglutamine
Authors: Hashimoto Tadashi , Sakura Naoki , Hirose Kyoko , Uchida Yoshiki , Nishijima Miwako , Moro Tadashi 
Published: July 2006

Abstract
Eight substance P analogs substituted by l- or d-pyrohomoglutamic acid (6-oxo-2-piperidinecarboxylic acid) and l or d-homoglutamine at the position 5 and 6 were prepared by the solid phase method. The contractile activities of the analogs were compared with that of SP on isolated guinea-pig organs.
The Pulse-Photoconductivity of Poly(1-vinylpyrene)
Authors: Itaya Akira , Okamoto Ken-ichi 
Published: July 2006

Abstract
The migration of electronic excitation energy, the steady-state photoconductivity, the hole-drift mobility and the carrier-photogeneration efficiency of holes in poly(1-vinylpyrene)(PVPy) films were investigated and compared with those in poly(N-vinylcarbazole)(PVCz) films. Although the concentration of the excimer-forming sites in PVPy films was about twenty times as large as that in PVCz films, the magnitude of the steady-state photoconductivity of PVPy was comparable to that of PVCz. The hole mobility in PVPy films was about one-half as large as that in PVCz films. The electric field and temperature dependence of the mobility fit Gill’s empirical equation. The carrier-photogeneration efficiency, Φ, of PVPy was larger than that of PVCz. The filed dependence of Φ of PVPy for all the excitation bands was in good agreement with the Onsager theory of geminate recombination. The high photoconductivity of PVPy could be explained on the basis of these results.
Asymmetric Synthesis of (2R,3S)-2,3-Epoxyoctanal, a Key Intermediate of 14,15-Leukotriene A4
Authors: Tsuboi Sadao , Furutani Hiroyuki , Takeda Akira 
Published: July 2006

Abstract
Asymmetric reduction of ethyl 3-chloro-2-oxooctanoate with baker’s yeast gave ethyl 3-chloro-2-hydroxyoctanoate (3) [(2S,3R)/(2S,3S), 4:1] in 67% yield with &gt;99% e.e. Chlorohydrin (2S,3R)-3 was converted to the titled compound in 34% total yield with 80% e.e. via the reduction, dehydrochlorination, and oxidation, successively. (2R,3R)2,3-Epoxyoctanal was also prepared from (2S,3S)-3 in 33% total yield with 94% e.e.
Binding Behavior of Metal Cations and Hydrophobic Ions from a Mixed Solution
Authors: Furusawa Kunio , Iwamoto Miyako , Matsumura Hideo 
Published: July 2006

Abstract
Critical experimental data are presented on the competitive adsorption of metal cations with different ionic valences to phospholipid vesicles, and on the binding of hydrophobic ions from mixed solutions with multivalent metal cations produced under different conditions by means of the Inductively Coupled Argon Plasma. It is apparent that the preferential effect in binding between the metal cations depends not only on their ionic valences but also on the concentrations of each ion at which the corresponding binding is carried out; i.e., the binding strength of the metal cations on the membrane surface increases in the following order: K+&lt;Mg2+&lt;Ca2+&lt;La3+&lt;Th4+, and this order comes to be more pronounced in the high-concentration region of each component. Furthermore, it is realized that, in binding from mixed solutions of hydrophobic ions and multivalent metal cations (Ca2+ or Th4+), a synergistic interaction between these ions occurs; i.e., the binding of hydrophobic anions is promoted by the presence of metal cations, while the binding of hydrophobic cations is hindered by the metal cations.
Mössbauer Spectroscopic Studies of Trialkyl- and Triaryltin Complexes of Transition Metal Cyanides
Authors: Katada Motomi , Uchida Yoshio , Iwai Kumiko , Sano Hirotoshi , Sakai Hiroshi , Maeda Yutaka 
Published: July 2006

Abstract
The structural diagnosis and lattice dynamics of three complexes, {[R3Sn](μ-NC)[Au(μ-CN)]}x (R=Me, Bu(n-Bu), or Ph), {[R3Sn]2[(μ-NC)4Pt]}x (R=Me, Bu, or Ph), and {[R3Sn]3[(μ-NC)6Fe]}x (R=Bu or Ph) have been undertaken by means of 57Fe-, 119Sn-, and 197Au-Mössbauer spectroscopic techniques. The Mössbauer parameters for the complexes indicate that all the tin atoms are coordinated with three alkyl or aryl groups and two cyano groups having a trigonal–bipyramidal structure. The asymmetry of the quadrupole split-peak intensity observed in the 119Sn-Mössbauer spectra for the complexes was attributed to the anisotropic mean square vibrational amplitude with respect to a molecular symmetry axis. The temperature dependence of the recoil-free fraction of the 119Sn-Mössbauer atom shows that the mean-square vibrational amplitude of tin atoms in the complexes falls in the range of values found for a number of one-dimensional organotin polymers. In 57Fe-Mössbauer spectroscopy, the quadrupole splitting for {[Bu3Sn]3[(μ-NC)6Fe]}x rapidly decreases with an increase in the temperature, reflecting small separations among the three dε levels in energy. The very large 197Au-quadrupole splitting for {[R3Sn](μ-NC)[Au(μ-CN)]}x was explained by assuming strong σ-donating and π-accepting properties of the CN ligand.
Reactivity of Hypervalent Species: Reactions of Anionic Penta-Coordinated Silicon Complexes towards Nucleophiles
Authors: Boudin Alain , Cerveau Geneviève , Chuit Claude , Corriu Robert J P , Reye Catherine 
Published: July 2006

Abstract
The reactivity of anionic penta-coordinated silicon complexes [RSi(O2C6H4-o)2]−Na+ 1 with nucleophilic reagents has been studied. 1 can be reduced to organosilanes RSiH3 by metallic hydrides. Reactions with an excess of Grignard or organolithium reagents (R′MgX or R′Li) gave tetraorganosilanes RSiR′3. When only two molar equivalents of Grignard reagents (R′MgX) or lithium reagents (R′Li) are added to complexs 1 functional silanes RR′2SiX can be prepared.
The 127I Nuclear Quadrupole Resonance of an Iodine Complex with 1,3-Dithiane, C4H8S2·2I2
Authors: Terao Hiromitsu , Sakai Hiroshi 
Published: July 2006

Abstract
The 127I nuclear quadrupole resonance spectrum of 1,3-dithiane–2I2 is reported. Two distinct S···I–I arrangements are present in the crystal. The charge on each iodine atom is obtained; the bonding in the complex is discussed in connection with analogous thioether–iodine complexes. The resonance lines for terminal iodine atoms indicate positive temperature coefficients.
Dynamic NMR as a Nondestructive Method for the Determination of Rates of Dissociation. XIII. Sulfur Inversion in 9,9-Dialkyl-10-mesitylthioxanthenium Salts
Authors: Oki Michinori , Yamada Yasuhisa 
Published: July 2006

Abstract
The sulfur-inversion in the title compound (alkyl=ethyl) was found to take place with the following activation parameters by dynamic NMR spectroscopy: ΔH\eweq=23.8±0.2 kcal mol−1, ΔS\eweq=2.6±0.4 cal mol−1 K−1. The significance of the near zero entropy of activation is discussed. The mesityl group in the title compounds also showed restricted rotation of which barrier to rotation was estimated to be 14 kcal mol−1 at 318 K for the compound where the alkyl is a methyl.
Metal(II) d-Tartrates Catalyzed Asymmetric Ring Opening of Oxiranes with Various Nucleophiles
Authors: Yamashita Hiroyuki 
Published: July 2006

Abstract
The asymmetric ring opening of meso-2,3-disubstituted oxiranes with thiols, aniline, and trimethylsilyl azide was studied by the use of metal(II) d-tartrates as heterogeneous chiral Lewis acid catalysts. The enantioselectivity varied widely with the combination of oxirane, nucleophile, and metal(II) d-tartrate, and Zn(II) d-tartrate gave the best enantioselectivity in the respective reactions of 1,2-epoxycyclohexane with 1-butanethiol, aniline, and trimethylsilyl azide to afford the corresponding adducts in 85, 58, and 42% ee, respectively. Furthermore, the kinetic resolution of racemic oxiranes with thiols catalyzed by Zn(II) d-tartrate was studied.
Chemistry of Germanium Atoms. II. Reactions of Thermally Evaporated Germanium Vapor with Organic Halides
Authors: Mochida Kunio , Tashiro Kumiko , Yoshida Yasuhiro , Mizuno Yasuhisa 
Published: July 2006

Abstract
Thermally generated germanium atoms were found to react with organic halides by insertion into carbon–halogen bonds. The resulting germylenes abstracted halogens from organic halides to form trihalogermyl derivatives. Tetrahalogermanes were also formed by the abstraction of halogens with germanium atoms.
Cathodic Addition of Benzylidyne Trichloride to Ketones and Aldehydes
Authors: Steiniger Michael , Schäfer Hans J 
Published: July 2006

Abstract
Ketones are converted to homologated enones 7a–g in good yields by cathodic addition of benzylidyne trichloride (1d). As intermediates α-chlorooxiranes 6 are assumed, which rearrange via α-keto carbenium ions 9 to enones. The intermediacy of 9 is supported by the addition of 1d to norcamphor, where the products indicate equilibrating norbornyl cations as intermediates. α,β-Unsaturated ketones lead depending on steric shielding of the double bond to the cyclopropane 23 as 1,4-adduct or the enone 26 as 1,2-adduct. With aldehydes and 1d, α-chloro or α-hydroxy ketones, the conversion products of 2-chlorooxiranes, are obtained.
Synthesis and Application of Some 1-[8-Hydroxy-5(or 7)-quinolinyl]alkylidene-Substituted Heterocycles as Bactericides, Funjicides, and Bioregulator
Authors: Khalil Zarif Haleem , Yanni Amal Sabet , Khalaf Ali Ali , Abdel-Hafez Ali Ali , Abdo Raafat Foaad 
Published: July 2006

Abstract
Interaction of 5-acetyl-8-quinolinol, corresponding 1-ethylquinolinium iodides, and 8-hydroxyquinoline-7-carbaldehyde with diethylmalonate under basic condition gave the corresponding of 4–6. Further reaction of 4–6 with hydrazine, phenyl hydrazine, hydroxylamine, urea, and/or thiourea gave the corresponding 1-[8-hydroxy-5(7)-quinolinyl]alkylidene-substituted heterocyclic derivatives (7–16) and corresponding 1-ethylquinolinium iodides (17–21). The structure of the synthesized compounds was confirmed by elemental and spectral analysis. The biological activity of 5-substituted 8-quinolinol was tested as microbicidal and bioregulator agents, the results obtained were interpreted according to their structure-activity relationships.
Behavior of the Enthalpy of Mixing in the Ternary Systems Lead–Antimony–Tin, Bismuth–Lead–Tin, and Bismuth–Cadmium–Tin at 950 K. I. Experimental Investigation
Authors: Badawi Walid Ahmad 
Published: July 2006

Abstract
Calorimetric studies on the enthalpies of mixing in the ternary systems Pb–Sb–Sn, Bi–Pb–Sn, and Bi–Cd–Sn have been carried out at 950 K. The partial enthalpy of mixing in the system Pb–Sb–Sn at quasi-binary section drawings goes through positive and negative regions. The partial enthalpy of mixing of lead is positive, while that of antimony is negative and takes a minimum between the quasi-binary section drawings xSn=0 and xSn⁄xPb=6⁄4. The partial molar enthalpy of mixing of bismuth in the ternary systems Bi–Cd–Sn and Bi–Pb–Sn shows level minima and the same behavior as observed for the partial enthalpy of mixing of antimony in the related system Pb–Sb–Sn. The partial enthalpy of mixing of tin in the system Bi–Pb–Sn is positive, while that of lead takes positive and negative values. Also the partial molar enthalpy of mixing of Cd in the system Bi–Cd–Sn shows a level minimum.
Synthesis and Epoxidation of Methyl trans-5,6-Diacetoxy-1,3-cyclohexadiene-1-carboxylate
Authors: Ogawa Seiichiro , Takagaki Tohei 
Published: July 2006

Abstract
The (±)-methyl 1,3-cyclohexadiene-1-carboxylate, a useful intermediate for synthesis of derivatives of shikimic acid, was prepared by bromination of (±)-methyl (1,3/2)-2,3-diacetoxy-4-cyclohexene-1-carboxylate, followed by debromination of the major dibromide obtained with zinc dust. Epoxidation of the diene with peracid gave selectively two 3,4-monoepoxides.
Thermodynamic Stability of Polycyclic Aromatic Hydrocarbons Detected in Our Environment
Authors: Aihara Jun-ichi 
Published: July 2006

Abstract
Various polycyclic aromatic hydrocarbons (PAHs) are distributed widely in our environment. Diesel particulate extract contains many larger PAHs. All these PAHs have a percent resonance energy larger than 2.50. Dibenzo[def,mno]chrysene and anthracene constitute the most unstable PAHs among them. A couple of reaction paths to the formation of ovalene are discernible in flames by inspecting the combustion products. It seems likely that a similar type of reactions take place in the envelopes of carbon stars to give large compact PAHs and graphite.
Mixed Surfactant Bilayers on Monodispersed Ferric Hydro Sols
Authors: Esumi Kunio , Sakamoto Yuichi , Yoshikawa Keiko , Meguro Kenjiro 
Published: July 2006

Abstract
The properties of mixed surfactant bilayers on monodispersed ferric hydro sol were studied by measuring the amount of surfactant adsorbed, particle size, and pyrene fluorescence spectra. The positively charged sols flocculated upon addition of sodium dodecyl sulfate (SDS) or lithium perfluoro-1-octanesulfonate (LiFOS) were redispersed by further addition of poly(oxyethylene) nonyl phenyl ether (NP7.5) due to the formation of a mixed surfactant bilayer on the sols. The mixed surfactant bilayer of SDS–NP7.5 on the sols was more easily formed than LiFOS–NP7.5. Fluorescence fine structure of pyrene gave information on the polarity of the microenvironment in the mixed surfactant layer on the sols.
Radical Cyclization in the Control of Regio- and Stereochemistry
Authors: Stork Gilbert 
Published: July 2006

Abstract
This article presents a review of the control of regio- and stereochemistry which is now possible by the use of the recently introduced haloacetal and the related halosilyl ether cyclizations, starting from a cyclohexenol or a cyclopentenol. The hydroxyl group is the control element which permits the addition of two carbon chains to the double bond of the allylic alcohol system, with complete regiospecificity and stereospecificity at the near end of the double bond, and with complete regiospecificity and high stereoselectivity at the far end of the bond. Examples of the use of the new methodology from the field of alkaloid, steroid and prostaglandin synthesis are given.
Transfer of Homologous Alkanols from Water to Fluorocarbon and Hydrocarbon Surfactant Micelles
Authors: Manabe Masahiro , Kawamura Hideo , Sugihara Gohsuke , Tanaka Mitsuru 
Published: July 2006

Abstract
The critical micelle concentration, cmc, of sodium perfluorooctanoate, SPFO, and sodium dodecyl sulfate, SDS, in the presence of two homologous series of alkanols (l-alkanols and ω-phenyl-l-alkanols) at very low concentrations of the alkanols Ca, was measured by a differential specific conductivity method. The free energy of transfer per CH2 group in the alkanols from water to the respective micelles, ΔG°(CH2), has been estimated from a linear relation of the rate of cmc-decrease, Δcmc/ΔCa, with the number of carbon atoms in the alkyl chain of alkanols. The respective values of ΔG°(CH2) obtained for two series of homologues added to a given surfactant are in good agreement with each other: ΔG°(CH2) is −1.73 kJ mol−1 in the SPFO system and −2.30 kJ mol−1 in the SDS system. The former has been found to be smaller in magnitude than the latter. On the basis of ΔG°(CH2), a thermodynamic parameter has been proposed which characterizes the degree of modification of a medium from its pure liquid state to surfactant micelles or to interfaces composed of a hydrocarbon or a fluorocarbon.
Liquid–Liquid Extraction of Some Class b Metal Ions with a Thiacrown Compound, 1,4,7,10,13,16-Hexathiacyclooctadecane
Authors: Sekido Eiichi , Kawahara Hideo , Tsuji Kaoru 
Published: July 2006

Abstract
The liquid–liquid extraction of various metal ions, especially of soft class b metal ions with a thiacrown compound, 1,4,7,10,13,16-hexathiacyclooctadecane (HTCO) using picrate ion (Pic−) was examined and compared with that of 1,4,8,11-tetrathiacyclotetradecane (TTCT). Although the extraction behavior of the class a, ab, and b metals with HTCO is fundamentally similar to that with TTCT, that of some metals belonging to class b metals with HTCO is different from that with TTCT. The extraction percentages of copper(II) and palladium(II) with HTCO are a few times larger than those with TTCT. Copper(I) and silver(I) are extracted with HTCO as the 1 : 1 complexes such as [Cu(htco)]+Pic− and [Ag(htco)]+Pic−, respectively, regardless of the relative concentration of the ligand to the metal. On the other hand, copper(I) and silver(I) complexes with TTCT are extracted with different compositions depending upon the relative concentration of the ligand to the metal.
t-Butylsulfinyl Phenylmethyl Carbanion. Conformation in Nonpolar Solvent
Authors: Ohno Atsuyoshi , Higaki Masato , Oka Shinzaburo 
Published: July 2006

Abstract
1H NMR spectra were studied for a carbanion derived from t-butyl phenylmethyl sulfoxide in tetrahydrofuran. It has been concluded that the conformation of the carbanion in solution is the same as that in a crystal. The carbanion exists in two diastereomeric dimeric forms in the presence of an equivalent amount of countercation, but it becomes a monomer when excess base exists in the solution.
Thermochemistry of Cobalt(III) β-Diketonates
Authors: Ribeiro da Silva Manuel A V , Ferrão Maria Luisa C C H 
Published: July 2006

Abstract
The standard molar enthalpies of formation of the crystalline complexes of cobalt(III) with 1-phenyl-1,3-butanedione (Hbzac), 2,2,6,6-tetramethyl-3,5-heptanedione(Hdpm), and 1,1,1-trifluoro-2,4-pentanedione (Htfac) were determined, at 298.15 K, by solution-reaction calorimetry:
ΔfH°m[Co(bzac)3,cr]=−877.1±8.7kJ·mol−1
ΔfH°m[Co(dmp)3,cr]=−1708±12kJ·mol−1
ΔfH°m[Co(tfac)3,cr]=−3191±15kJ·mol−1
The enthalpies of sublimation of Co(dpm)3 and Co(tfac)3, at 298.15 K, determined by high-temperature microcalorimetry were 126±3 and 114±2 kJ·mol−1, respectively. From the enthalpies of formation of the gaseous complexes, the average molar bond-dissociation enthalpies, 〈D〉(Co–O), were derived.
Hindered Rotation around Csp2–Csp3 Bonds in the Enol Forms of α-(9-Fluorenyl)-β-diketones and in 3,5-Disubstituted 4-(9-Fluorenyl)pyrazoles. An 1H NMR Study
Authors: Moreno-Mañas Marcial , Gonzalez Asensio , Marquet Jorge , Sanchez-Ferrando Francisco 
Published: July 2006

Abstract
Slow rotation around the Csp2–Csp3 bonds of the enol forms of 3-(9-fluorenyl)-2,4-pentanedione, 2-(9-fluorenyl)-1-phenyl-1,3-butanedione, and the corresponding bonds of the derived pyrazoles, was studied by variable temperature 1H NMR. For the pyrazoles, the values Tc=315–320 K (ΔGTc\eweq=15.1±0.1 kcal mol−1) and Tc=338±5 K (corresponding to ΔGTc(sp→ap)\eweq=18.1±0.2 kcal mol−1 and ΔGTc(ap→sp)\eweq=16.1±0.2 kcal mol−1) were found, respectively.
Optical Absorption by Mn2+ Ions in MnM(edta)·6H2O (M=Zn, Cu, Ni, and Co)
Authors: Togashi Hisashi , Kojima Norimichi , Ban Toshiro , Tsujikawa Ikuji 
Published: July 2006

Abstract
The optical absorption spectra of the Mn2+ ion in MnM(edta)·6H2O (M=Zn, Cu, Ni, and Co) were measured at low temperature. Fine structural bands corresponding to the 6A1g→4T2g (D) and 6A1g→4A1g, 4Eg (G) transitions were found. The fine structure corresponding to the 6A1g→4A1g, 4Eg (G) transition in the Zn compound were analyzed with the ligand field theory and the assignment of the absorption peaks was performed. Although the spectra of the Zn, Cu, and Co compounds are similar, those of the Ni compounds show significant broadening, which is possibly due to the energy transfer caused by the overlapping of the absorption bands of the Ni2+ and Mn2+ ions.