bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of the Co(III) Complexes with a Tridentate Hexaniobato and a Bi- or Tri-dentate Amino Carboxylato Ligand
Authors: Hosokawa Yutaka , Hidaka Jinsai , Shimura Yoichi 
Published: July 2006

Abstract
Twelve new Co(III) complexes containing a hexaniobate ion Nb6O198− as a tridentate ligand were synthesized. The hexaniobato ligand coordinates facially, and the remaining three coordination sites are occupied by a tridentate amino carboxylato ligand or by a bidentate amino carboxylato ligand and NH3 or H2O. Two glycinato complexes, [Co(Nb6O19)(gly)(X)]6− (X=NH3 or H2O), were optically resolved, and a l-valinato complex [Co(Nb6O19)(l-val)(NH3)]6− was separated into two diastereomers. The structures of these complexes were determined from their visible and ultraviolet absorption, circular dichroism, and proton magnetic resonance spectra.
Chemistry of Nitrosoimines. X. Reactions of 3-Substituted 2-Nitrosoimino-2,3,-dihydrobenzothiazoles with Aryl and t-Butyl Grignard Reagents
Authors: Akiba Kin-ya , Kawamura Takayuki , Hisaoka Motoyuki , Inamoto Naoki 
Published: July 2006

Abstract
3-Substituted 2-nitrosoimino-2,3-dihydrobenzothiazoles (1) react with arylmagnesium bromide to give 3-substituted 2,2-diaryl-2,3-dihydrobenzothiazoles as the major product and 2-N′-arylhydrazono-2,3-dihydrobenzothiazoles as a minor product. 1 reacts also with t-butylmagnesium chloride to give 3-substituted 2-t-butyl- and 2-N′-t-butylhydrazono-2,3-dihydrobenzothiazoles and 2,3-dihydrobenzothiazol-2-one. Reaction of 1 with mesitylmagnesium bromide gave a similar result to that with t-butylmagnesium chloride.
Chemistry of Nitrosoimines. XIII. Reactions of 3-Substituted 2-Nitrosoimino-2,3-dihydrobenzothiazoles with Organolithiums
Authors: Hisaoka Motoyuki , Akiba Kin-ya , Inamoto Naoki 
Published: July 2006

Abstract
Reactions of 3-substituted 2-nitrosoimino-2,3-dihydrobenzothiazoles (1) with phenyl- and n-butyllithiums give the corresponding (N-substituted o-amino)phenyl sulfides as the major product due to direct attack on the sulfur atom of the benzothiazoline ring, while that with benzyllithium gives 2,2-dibenzyl derivatives and bis[o-(N-substituted amino)phenyl] disulfides. The difference between the reactions of 1 with Grignard reagents and those with organolithiums has been explained by the difference of the coordination site, thiophilicity and the ionic character of the reagents.
Reactions between Nucleophiles and Sulfonium Ions Containing Electron-withdrawing Substituents
Authors: Matsuyama Haruo , Minato HirosHi , Kobayashi Michio 
Published: July 2006

Abstract
Sulfonium ions containing electron-withdrawing substituents are formed by the reactions between sulfonium ylides and suitable electrophiles. Reactivities of these sulfonium ions (MeR\overset+S–CX(CO2Me)2) with nucleophiles (Y−) are investigated. The products found are those of 1) C-attack (MeSR+YCX(CO2Me)2), 2) Me-attack (MeY+RSCX(CO2Me)2) and 3) R-attack (RY+MeSCX(CO2Me)2). When R is (+)-2-octyl and Y− is bromide ion, the RY found is (−)-2-octyl bromide with 59% optical purity. The mechanism of these reactions are discussed.
The Substituent Effect. VI. Inductive and π-Electronic Effects in the Phenol Hydroxyl Chemical Shifts in DMSO
Authors: Tsuno Yuho , Fujio Mizue , Yukawa Yasuhide 
Published: July 2006

Abstract
Substituent effects on the NMR chemical shifts of the hydroxyl proton of m- and p-substituted phenols in DMSO have been studied by means of the LSFE equation. The effect of substituents was found to be considerably modified in the DMSO solution as compared with that in aqueous solution through strong substituent-solvent interactions. The LSFE equation was applied to the apparent substituent effects of such solvent-modified systems, and the practical set of parameters for the inductive and the π-electronic effects of the DMSO-modified substituents were estimated. The treatment was successful for +R substituents but not for −R substituents. This may be attributed to the much stronger solvent-substituent interactions. Characteristic features of LSFE treatment were discussed in comparison with Taft and Swain-Lupton treatments. It is suggested that the dual resonance reaction constants for +R and −R para substituents are required for Taft-type correlations.
X-Ray Photoelectron Spectroscopy of 1,10-Phenanthroline Metal Chelates
Authors: Yoshida Tooru , Sawada Shigemasa 
Published: July 2006

Abstract
Photoelectron spectra of several phenanthroline metal chelates were measured and the shifts of the N(1s) binding energy were plotted against the electronegativities of the metals. The plotted points appeared to fall into two groups, one for transition-metal chelates and the other for the other metal chelater.
Proton Transfer Reactions in Oxygen-Containing Molecules and Ammonia Mixtures
Authors: Matsumoto Akira , Okada Satoshi , Taniguchi Setsuo , Hayakawa Teruo 
Published: July 2006

Abstract
Ion-molecule reactions leading to the formation of NH4+ in a number of mixtures of oxygen-containing molecules and ammonia have been studied using pulsedsource mass spectrometry. Some unique features in the reactivities of C2H4O+ and CHO+ ions from ethylene oxide have been found.
Solvent Effect on the Dimerization of Tetracyanoquinodimethane Anion Radical
Authors: Sakata Tadayoshi , Nakane Akihiro , Tsubomura Hiroshi 
Published: July 2006

Abstract
The thermodynamic quantities of the dimerization of tetracyanoquinodimethane (TCNQ) anion radical in water–ethanol mixtures were determined. The free energy of dimerization −ΔG showed a monotone decrease with an increase in ethanol content, whereas the enthalpy and the entropy of dimerization, −ΔH and −ΔS, showed a maximum. This unusual behavior is explained by proposing a solvation model in which the water molecules are attracted more strongly around the TCNQ− dimer than are the ethanol molecules. The entropy was found to play an important role in the dimerization.
Infrared Band Shape of the C–I Stretching Vibration of Methyl Iodide in Solutions
Authors: Fujiwara Kenji , Fukushi Kohji , Ikawa Shun-ichi , Kimura Masao 
Published: July 2006

Abstract
The infrared band shapes of the fundamental and overtone C–I stretching vibrations of methyl iodide in solutions are well approximated by the superposition of Lorentzian functions. From a comparison of the bandwidths of the ν3(→1), ν3(1→2), and ν3(0→2) transitions, it is pointed out that the vibrational relaxation of the translational-diffusion type proposed by Bratos et al. contributes to the band-widths, in addition to reorientational relaxation. A slight deviation from the Lorentzian function was observed in the low-frequency region of the fundamental band.
Nuclear Quadrupole Resonance of Tellurium Tetraiodide
Authors: Okuda Tsutomu , Yamada Koji , Furukawa Yoshihiro , Negita Hisao 
Published: July 2006

Abstract
The nuclear quadrupole resonance (NQ R) of 127I in tellurium tetraiodide was observed, and the Zeeman effect on a single crystal was examined. Tellurium tetraiodide shows ten resonance lines in the frequency range from 195 to 260 MHz. From the analysis of the zero-splitting patterns, it has become apparent that tellurium tetraiodide crystals contain eight nonequivalent iodine atoms, two of which yield large asymmetry parameters (94.9% and 73.8%) and small quadrupole coupling constants (775.07 MHz and 929.55 MHz) at room temperature. These two may be assigned to the bridging iodine atoms, but they differ markedly from each other in the temperature dependences of e2Q q/h and η. The other six iodine atoms have small η values and coupling constants of about 1600 MHz; they are assigned to the terminal atoms. From these results, it may be concluded that each tellurium atom has three terminal and two bridging iodine atoms.
Microwave Spectrum of Ethylene Oxide in Excited Vibrational States
Authors: Yoshimizu Nobuaki , Hirose Chiaki , Maeda Shiro 
Published: July 2006

Abstract
In the rotational spectrum of ethylene oxide, the five lowest-lying vibrational states are assigned and the vibration-rotation constants and the centrifugal distortion constants are derived. The vibrational frequencies are estimated from relative intensity measurements at νa=803±18 cm−1 and νb=814±23 cm−1 for the antisymmetric species (with respect to the C2 operation) and at νc=872±34 cm−1, νd=1020±33 cm−1, and νe=1109±42 cm−1 for the symmetric species. The intensity measurements of the remaining spectral lines showed that these lines belong to vibrational states at frequencies above about 1000 cm−1. The νa, νb, and νc states are tentatively assigned to ν15, ν12, and ν5, respectively, by taking into account the Goriolis interactions.
Partition Coefficients of Alkanols and Polyoxyethylene Alkyl Ethers in the Dodecane–Water System at 25 °C
Authors: Manabe Masahiro , Koda Masaharu , Shirahama Keishiro 
Published: July 2006

Abstract
The partition coefficients of normal alkanols (RmOH, m=2 to 6) and a number of polyoxyethylene normal alkyl ethers (RmEnOH, n=1,2 m=2 to 5; n=3, 4m=4,5) in the dodecane-water system have been determined at a high dilution at 25 °C. From the finding that the standard free energies of the transfer of the solutes from water to the dodecane phase show a linear relation with the number of methylene and oxyethylene groups, the contribution of the groups to the free energy was obtained as −0.858 for alkanols and −0.808 kcal/mol methylene group for ethers, and 0.655 kcal/mol oxyethylene group respectively. Extrapolation to zero oxyethylene in the linear relationship for the normal alkylethers gave standard free energies of transfer less than those for normal alkanols with the same alkyl chain length. Thus, the alkanol is more hydrophilic than the hypothetical “ether” with no oxyethylene group. The difference in the free energies is discussed from the viewpoint of intramolecular hydrogen-bond formation in the polyoxyethylene chain in the dodecane phase.
Effect of the Viscosity Ratio, μd/μc, on the Particle-size Distribution in Emulsions
Authors: Tsukiyama Shun’ichi , Takamura Akira , Fukuda Yasuko , Koishi Masumi 
Published: July 2006

Abstract
The object of this paper is to investigate the effect of the ratio of the viscosities of dispersed and continuous phases, μd⁄μc, on the particle-size distribution in o/w-type emulsions. The viscosity ratios (μd⁄μc) used were 0.836 : 1, 0.271 : 1, 0.0992 : 1, 0.0280 : 1, and 0.00133 : 1. The size of the dispersed liquid droplets was measured by the microphotographic method. The mean diameter and the particle-size distribution were determined, and, further, the specific interfacial energy was evaluated. When the viscosity ratio was much smaller than unity, the particle-size distribution showed a skewed curve. On the contrary, the specific interfacial energy increased remarkably as the viscosity ratio approached unity.
Circular Dichroism of Chromium(III) Complexes. V. Circular Dichroism of traras-Dihalogenobis(diamine) Complexes with Optically Active Diamines
Authors: Kaizaki Sumio , Shimura Yoichi 
Published: July 2006

Abstract
Nine chromium(III) complexes of trans-[CrX2(N)4] type with three kinds of optically active diamines (R-propylenediamine, S,S-stilbenediamine and S,S-2,4-pentanediamine) were prepared and the absorption and circular dichroism spectra were measured in the region of their d–d transitions. The CD behaviors in the spinallowed transitions were discussed in comparison with the corresponding cobalt(III) complexes and their bands were assigned to the tetragonal components. On the basis of the theoretical correlation between the rotational strengths for the spin-forbidden transitions and for the spin-allowed transitions, the CD peaks in the spin-forbidden transitions were discussed and assigned.
Synthesis and Rearrangement of Ethyl Aryloxyglyoxalate Arylhydrazones
Authors: Shawali A Sami , Eweiss N F , Hassaneen H M , Sami M 
Published: July 2006

Abstract
Ethyl chloroglyoxalate arylhydrazones (III) react with sodium phenolates in ethanol and give ethyl aryloxyglyoxalate arylhydrazones (IV). The latter ester hydrazones rearrange at high temperatures to the hydrazides (V). Structural assignments have been made on the basis of elemental and spectral analyses and independent chemical evidence whenever possible.
Charge-transfer and Proton-transfer in the Formation of Molecular Complexes. XI. Phase Transitions in Hertel’s Picric Acid Complexes
Authors: Matsunaga Yoshio , Osawa Eiji , Osawa Ryuzo 
Published: July 2006

Abstract
The isomerization from true phenolates to charge-transfer complexes by phase transitions in Hertel’s five amine-picric acid complexes was confirmed by spectroscopic examinations. The amines and the estimated heats of transition were as follows: o-bromoaniline, 6.7; o-iodoaniline, 6.2; 1-chloro-2-naphthylamine, 8.0; 1-bromo-2-naphthylamine, 8.2; 1,6-dibromo-2-naphthylamine, 3.3 kcal/mol. The transition temperatures and/or the heats in the naphthylamine complexes were shown to be markedly reduced by crushing the crystals. The chargetransfer complexes have electrical resistivities lower by a factor of many decades than the isomeric phenolates. Phase transitions without isomerization were found in the metastable 1-halo-2-naphthylamine complexes of the charge-transfer type.
An X-Ray Diffraction Study of a Concentrated Aqueous Sodium Iodide Solution
Authors: Maeda Masunobu , Ohtaki Hitoshi 
Published: July 2006

Abstract
X-Ray diffraction measurements of a 7 M NaI aqueous solution showed that iodide ion is surrounded by approximately six water molecules, the I−–H2O distance being 3.60 Å and that sodium ion is bonded to about four water molecules at the distance of 2.4 Å.
Photoelectron Spectra of the cis- and trans-Isomers of Some Ethylene Derivatives
Authors: Kobayashi Tsunetoshi , Yokota Katsuyuki , Nagakura Saburo 
Published: July 2006

Abstract
The photoelectron spectra of cis- and trans-stilbenes, fumaric acid, dimethyl maleate, and dimethyl fumarate were measured and interpreted, special attention being paid upon their difference between the corresponding trans- and cis-isomers. The two characteristics were found for the photoelectron spectra of cis- and trans-stilbenes: (1) the splitting between the first and fifth bands is smaller for the cis-isomer (steric-hindrance effect); (2) the splitting between the second and third bands is larger for the cis-isomer (through-space interaction). The difference in the carbonyl n orbital ionization potentials between dimethyl maleate and fumarate was interpreted in terms of through-bond interaction.
The Triplet-Triplet Absorption Spectra and Electronic Structures of Some Cyano-Substituted Benzenes
Authors: Morita Hiroshi , Matsumoto Satoru , Nagakura Saburo 
Published: July 2006

Abstract
Triplet-triplet (T–T) absorption bands were observed at 300, 297, and 320 nm for m- and p-dicyanobenzenes, and 1,3,5-tricyanobenzene, respectively. The nature of the observed spectra was investigated by calculating the wave functions of the triplet states and by analyzing them by the configuration analysis method. It was concluded that the T–T absorption bands of m- and p-dicyanobenzenes, and 1,3,5-tricyanobenzene correspond essentially to the transition from the locally (within the benzene ring) excited state to the intramolecular charge-transfer state.
Thermal Dehydration and Decomposition Reactions of Bivalent Metal Oxalates in the Solid State
Authors: Nagase Kenzo , Sato Katsuya , Tanaka Nobuyuki 
Published: July 2006

Abstract
The thermal dehydration and decomposition of the oxalates of Mg(II), Ca(II), Sr(II), Ba(II), Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) were investigated by means of TG, DTA, DSC, EGA, X-ray powder diffraction analysis, and reflectance and infrared spectroscopies. In general, the temperature at which the oxalates were dehydrated increased with 1/r, where r denotes the radius of metal ion. The heats of dehydration (ΔHH2O) of the alkaline earth metal oxalates increased with 1/r, but those of transition metal oxalates decreased as 1/r increased. By considering the decomposition products, the reactions of anhydrous oxalates were classified into three groups and the relations between the decomposition temperatures and 1/r were discussed for each group.
Photochemical Deuteration of ortho-Substituted N-(Diphenylmethylene)acetamides
Authors: Saeki Masaru , Toshima Naoki , Hirai Hidefumi 
Published: July 2006

Abstract
The alkyl hydrogens of N-(2-alkyldiphenylmethylene)acetamides were found to be readily replaced with deuterium on irradiation in deuteriomethanol (CH3OD). It is proposed that the deuteration proceeds via an enamide isomer produced by intramolecular hydrogen transfer from the o-alkyl group to the excited C=N double bond. An intermolecular hydrogen atom abstraction pathway was excluded because neither N-(4-methyldiphenylmethylene)acetamide in deuteriomethanol(CH3OD) nor diphenylmethane in deuteriomethanol(CH3OD) in the presence of N-(diphenylmethylene)acetamide was deuterated. Intramolecular hydrogen abstraction is essential for the deuteration, because no deuteration occurs on irradiation of 2-methylbenzophenone semicarbazone which undergoes no photoreduction. The difference in reactivities of the ortho-substituted imines between in solution and in a rigid matrix is discussed from the viewpoint of syn-anti isomerization.
Hetera-p-carbophanes. III. Conformation of Amide Groups in and Internal Rotation of Diaza[n]paracyclophanes with Two Alkoxy Groups at the Benzene Ring
Authors: Sakamoto Kazuhiko , Oki Michinori 
Published: July 2006

Abstract
A series of diazadioxo[n]paracyclophane derivatives with two alkoxy groups at the benzene ring were prepared. The conformation of amide groups in these compounds were studied by infrared, PMR, and 13C NMR spectra to draw a conclusion that both amide groups are s-trans. Thus the infrared absorptions at 3430 and 3405 cm−1 are attributed to N–H···π interacting and N–H···O bonded trans forms, respectively. NCH2 protons, which are separated by 5 bonds from the asymmetric center, as well as benzylic protons, were found to be non-equivalent when the rotation of the aromatic ring was slow. PMR spectra of the compounds studied at various temperatures indicate that introducing alkoxy groups in place of methyls at the benzene ring increases the barrier to rotation of the aromatic ring to a great extent.
The Crystal Absorption Spectra of Some Hexachloroiridate(IV) Salts
Authors: Urushiyama Akio , Nakahara Masayoshi , Kondo Yukio 
Published: July 2006

Abstract
The absorption spectra of the single-crystals of several hexachloroiridate(IV) salts and the doped crystals of the hexachlorostannate(IV) salts and the hexachloroplatinate(IV) salt with the IrCl62− anion were measured. Distinct dichroisms appeared in the polarized absorption spectra of all the anisotropic crystals studied. The splittings of the bands and the dichroisms of the spectra were interpreted in terms of the lowering of the symmetry of the IrCl62− anions in the crystal. The absorption bands at 19760 and 20000 cm−1 in the spectra of (CH3NH3)2-Sn(Ir)Cl6 could be assigned to the E′g→E″u and E′g→E′u transitions respectively from their polarizations in the double group, D3d*. Similarly, the bands at 23100, 23500, and 24500 cm−1 were assigned to the E′g→E′u, E′g→E″u, and E′g→E′u transitions respectively. The polarized absorption spectra of Na2IrCl6·6H2O and Na2Pt-(Ir)Cl6·6H2O were also interpreted, assuming that the IrCl62 anions in these crystals were of the D4d symmetry.
The Stereochemistry of Autoxidation of Methylcyclohexanes
Authors: Miyajima Shingo , Simamura Osamu 
Published: July 2006

Abstract
Autoxidation of 1, c-3, c-5- or 1, c-3, t-5-trimethylcyclohexane with oxygen in the presence of azobisisobutyronitrile at 60°C and subsequent reduction with lithium aluminium hydride gave 1, t-3, t-5- and 1, c-3, c-5-trimethyl-r-1-cyclohexanol in the same ratio of 1/0.85. Such an almost random attack of oxygen on both sides of intermediate methylcyclohexyl radicals was also observed in autoxidation of 1,2-dimethyl-, 1,4-dimethyl-, and 1,1,3,5-tetramethylcyclohexanes. Approximate relative reactivities of tertiary hydrogens in various steric environments in methylcyclohexanes towards abstraction were determined. Steric effects on the attack of oxygen and the abstraction of hydrogen are discussed.
Synthesis of Di-N-acetyl-di-N-benzyloxycarbonyl-O-cyclohexylidenestreptidine
Authors: Umezawa Sumio , Takahashi Yoshikazu , Tsuchiya Tsutomu 
Published: July 2006

Abstract
Reaction of streptidine with excess benzyloxycarbonyl chloride, followed by partial alkaline hydrolysis, gave di-N-benzyloxycarbonylstreptidine (1), which, by treatment with 3,4-dihydro-2H-pyran, gave a tetra-O-tetra-hydropyranyl derivative (3). Acetylation of 3 then gave a di-N-acetyl derivative (4), which was, after removal of the tetrahydropyranyl groups, allowed to react with 1,1-dimethoxycyclohexane to furnish di-N-acetyl-di-N-benzyloxycarbonyl-O-cyclohexylidenestreptidine (6). This is the first preparation of a useful intermediate for the synthesis of streptidine glycosides.
The Michael Reactions of Chloro-substituted-9,9′-bifluorenylidenes with Fluorenes and a Comparison with Analogous Halogen Compounds
Authors: Minabe Masahiro , Suzuki Kazuo 
Published: July 2006

Abstract
The Michael reactions of 2-chloro- and 2,7-dichloro-9,9′-bifluorenylidenes with fluorenes were investigated. Structures of these products were confirmed by syntheses through the well-established reactions of 9-lithiofluorenes and 9-bromo-9,9′-bifluorenyls. The formation of some abnormal compounds is explained by intermediary formation of 2,7-dichloro-9,9′-bifluorenylidene from the reaction of 9,9′-bifluorenylidene with 2,7-dichlorofluorene as with the bromo-derivatives. The corresponding fluoro- and iodo-series gave predominantly normal addition products. These differences are explained in terms of the inductive and steric effects of the halogen substituents.
Theoretical Study of Proton Chemical Shifts Induced by the Paramagnetic Anisotropy of Cobaltic Ion
Authors: Nakashima Yoshiaki , Sakaguchi Ushio , Yoneda Hayami 
Published: July 2006

Abstract
A new theoretical relation between proton and cobalt-59 chemical shifts in cobalt(III) compounds has been established on the assumption that the proton shift comes primarily from the anisotropy of the second-order paramagnetism of the central cobalt(III) ion. The additivity observed for cobalt-59 chemical shifts in solution is explained and applied to the problem of proton shifts. The relation between 1H and 59Co chemical shifts, coupled with this additivity, allows one to calculate the chemical shift of a proton under the influence of the paramagnetic anisotropy of a cobalt ion.
Proton Magnetic Resonance Spectra of Metal Ammine Complexes. III. Interpretation of the Chemical Shifts in Cobalt(III) Pentaammines
Authors: Nakashima Yoshiaki 
Published: July 2006

Abstract
The ammine proton chemical shifts of a series of compounds [CoX(NH3]n+ have been explained quantitatively. The shifts are ascribed to the paramagnetic anisotropy of central cobalt(III) ions. The discrepancies between the calculated and the observed shift values, though small, noted for the trans ammine protons of complexes with X=CN− and NO2− may be caused by large inductive effects of these ligands.
Theoretical Considerations of Lower Excited States of trans-Polyenecarbaldehydes. II. Radiative and Nonradiative Properties
Authors: Inuzuka Kozo 
Published: July 2006

Abstract
The spin-orbit coupling energies between the lowest 1(n,π*) and 3(π,π*) states, and between the lowest 1(π,π*) and 3(n,π*) states, for the four polyenecarbaldehydes were calculated using the results calculated within the framework of the conventional P–P–P SGF–MO–CI method. In the present paper, the general properties of the emission spectra of polyenecarbaldehyde are theoretically considered using the calculated results for the spin-orbit coupling energy and their lower electronic structure.