bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectrophotometric Determination of Micro Amounts of Pentathionate via Permanganate Reaction
Authors: Miura Yasuyuki , Koh Tomozo 
Published: July 2006

Abstract
A method has been developed for the determination of micro amounts of pentathionate. It is based on the reaction of pentathionate with a given amount of permanganate in a dilute sulfuric acid medium and on the spectrophotometric measurement of iodine as triiodide, which is formed by the oxidation of iodide with an excess of permanganate. The analytical conditions were established by varying the temperature, reaction time, and amounts of sulfuric acid and permanganate. The present method can be successfully applied to a determination of pentathionate in the range 2×10−7 to 1.4×10−5 mol dm−3 (0.5–35.9 μg S5O62− in 10 cm3) and gives a higher sensitivity than any previous method without solvent extraction. In eleven determinations for 10 cm3 sample solutions containing 0.080 μmol of pentathionate, the present method gave a mean value of 0.0 with a standard deviation of 0.0006 μmol and a relative standard deviation of 0.75%.
A Novel Rearrangement of Protonated 2-Bromo-5-methylthiophene
Authors: Yokoyama Yukihiro , Yamashita Yukihide , Takahashi Kensuke , Sone Tyo 
Published: July 2006

Abstract
A novel rearrangement of protonated 2-bromo-5-methylthiophene was observed in HSO3F by means of 1H NMR spectroscopy.
17O NMR Studies on a Series of Manganese Carbonyl Derivatives with Sn–Mn Bond(s)
Authors: Onaka Satoru , Sugawara Tadashi , Kawada Yuzo , Yokoyama Yukihiro , Iwamura Hiizu 
Published: July 2006

Abstract
17O NMR spectra were measured for a series of manganese carbonyl derivatives, (CH3)xCl3−xSn–Mn(CO)5−yLy and (CH3)3−xSn[Mn(CO)5−yLy]x+1(L=P(OPh)3). 17O chemical shifts were correlated with carbonyl stretching frequencies, 119Sn-Mössbauer isomer shifts, and 55Mn NMR chemical shifts. From these correlations, 17O chemical shifts were interpreted in terms of σ- and π-electron acceptance of the tin moieties. It was also clarified that 17O NMR spectroscopy is a direct method to study electronic nature around the oxygen atoms in metal cluster compounds such as Me2Sn[Mn(CO)5]2 and MeSn[Mn(CO)5]3. 55Mn NMR spectra were also measured for some of these compounds to corroborate the 17O NMR results.
Photoinduced Hydrogen Evolution with Hydrogenase Using Bipyridinium Salts as Electron Carriers
Authors: Okura Ichiro , Fujie Hiroki , Aono Shigetoshi , Kita Tatsuya , Kaji Naruhiko 
Published: July 2006

Abstract
Photoinduced hydrogen evolution was carried out by using bipyridinium salts as electron carriers. Hydrogen evolution rate strongly depends on the type of bipyridinium salt. The order of the rate values undergoes a change by the change in the rate-determining step.
Stopped-Flow Investigation of Antioxidant Activity of Tocopherols
Authors: Mukai Kazuo , Watanabe Yoshiko , Uemoto Yuichi , Ishizu Kazuhiko 
Published: July 2006

Abstract
It was observed by ESR measurement that the oxidation of α-, β-, γ-, and δ-tocopherols (vitamin E) with a stable phenoxyl radical in benzene immediately gives corresponding tocopheroxyl radicals. The rates of reaction of α-, β-, γ-, and δ-tocopherols with the stable phenoxyl radical in ethanol solution have been determined spectrophotometrically using stopped-flow technique, as a model reaction of tocopherols with unstable free radicals (ROO·, RO·, and HO·) in biological systems. The second-order rate constants obtained are (5.12±0.36)×103 (α-Toc), (2.24±0.04)×103 (β-Toc), (2.42±0.16)×103 (γ-Toc), and (0.51±0.01)×103 (δ-Toc), M−1 s−1 in ethanol at 25.0 °C. The relative rates agree well with those obtained from studies of the reactivities of tocopherols toward poly(styrylperoxyl) and galvinoxyl radicals by O2 consumption and by ESR method, respectively. The results suggest that the relative reactivities, that is, relative antioxidant activities of tocopherols do not depend on the kinds of unstable free radicals reacted.
Optically Active Cyclic Dipeptide Carrying 9-Anthryl Groups
Authors: Egusa Syun , Sisido Masahiko , Imanishi Yukio 
Published: July 2006

Abstract
Optically active 3-(9-anthryl)alanine was synthesized for the first time and its cyclic dipeptide, cyclo(d-9-anthrylalanine)2, was prepared. Conformation of the cyclic dipeptide in solution was investigated by means of 1H NMR, absorption, circular dichroism (CD), and fluorescence spectroscopy. The coupling parameter JNH-CαH, observed in the NMR spectra indicated a planar configuration for the 2,5-piperazinedione ring of the dipeptide. The cyclic dipeptide showed a moderately large exciton couplet in CD spectrum and a small splitting in the 1Bb absorption band, but no excimer emission in fluorescence spectrum. These spectroscopic data suggest an unfolded-unfolded conformation for the side chains of the cyclic dipeptide.
Oxidation of Lipids. XIV. Inhibition of Oxidation of Methyl Linoleate by Fatty Acid Esters of l-Ascorbic Acid
Authors: Takahashi Mareyuki , Niki Etsuo , Kawakami Akira , Kumasaka Akira , Yamamoto Yorihiro , Kamiya Yoshio , Tanaka Kunihiko 
Published: July 2006

Abstract
Various kinds of fatty acid esters of l-ascorbic acid were synthesized and their role as chain-breaking antioxidant was studied in the oxidation of methyl linoleate in homogeneous solution. Fatty acid esters of ascorbic acid at either 6- or both 5- and 6-positions were effective as antioxidant and suppressed the oxidation of methyl linoleate, whereas those having ester group at 2-position did not act as antioxidant. 5,6-Erythorbyl dipalmitate was also effective as an antioxidant. Ascorbic acid esters inhibited the oxidation cooperatively with α- and δ-tocopherols as observed for free ascorbic acid. The antioxidant activity was correlated with the reactivity toward galvinoxyl radical.
Synthesis of Unusual Aromatic l-Amino Acids by Asymmetric Hydrogenation of Cyclic Dehydrodipeptides
Authors: Aoyagi Haruhiko , Horike Fumio , Nakagawa Atsuko , Yokote Sayuri , Park Namgyu , Hashimoto Yoshihide , Kato Tetsuo , Izumiya Nobuo 
Published: July 2006

Abstract
To prepare l-Tyr(Me) and l-Amp (l-2-amino-5-(p-methoxyphenyl)pentanoic acid), their precursors cyclo(–ΔTyr(Me)–l-Ala–) and cyclo(–ΔAmp–l-Ala–) were hydrogenated in N,N-dimethylformamide. The content of Ll isomers in the hydrogenated products was over 94%. Mild acid hydrolysis of the hydrogenated products and subsequent recrystallization gave pure l-Tyr(Me) and l-Amp.
Mass Spectra of Tetrahydrofuran Derivatives
Authors: Nagano Hajime , Ijiri Makiko , Xu Xiao Hong , Shiota Michio 
Published: July 2006

Abstract
Mass spectra of 2-(4,5-dialkyloxacyclopent-2-yl)-2-propanols exhibited a characteristic cleavage of tetrahydrofuran ring yielding an ion at m⁄z 102 (C5H10O2) and/or an ion (M+–C5H10O2–H).
A Time-Resolved ESR Study on the Photochemical Reduction of Nitrobenzene Derivatives in Alcoholic Solution
Authors: Akiyama Kimio , Ikegami Yusaku , Ikenoue Tsuneo , Tero-Kubota Shozo 
Published: July 2006

Abstract
Time-resolved ESR experiments have been carried out to elucidate the initial process in the photochemical reduction of aromatic nitro compounds. The first observation of CIDEP due to nitrobenzene anion radicals in the presence of an electron donor proved that radical generation takes place through a triplet mechanism.
13C NMR Spectra of 1,3-Dithiolan-2-ylium Ions and 2-Alkylidene-1,3-dithiolanes
Authors: Okuyama Tadashi , Fueno Takayuki 
Published: July 2006

Abstract
13C NMR spectra of various 2-substituted 1,3-dithiolan-2-ylium perchlorates 5 as well as 2-alkylidene-1,3-dithiolanes 6 are measured. Chemical shifts induced by protonation of 6 to form 5 are compared with those found with the unsaturated analogues, 1,3-dithiolylium ions, implying the aromatic charge delocalization in the latter ions.
The Preconcentration and Separation of a Trace Amount of Copper(II) in Water as Its Silica-Immobilized Salicylaldimine Chelate by Means of Column Chromatography
Authors: Honjo Takaharu , Makino Tetsuji 
Published: July 2006

Abstract
The behavior of a trace amount of copper(II) in solid-liquid extraction and back extraction has been examined with silica-immobilized salicylaldimine; the results have also been applied to the preconcentration and separation of a trace amount of copper(II) in water as its silica-immobilized salicylaldimine chelate by means of column chromatography.
Surface Analysis of MF–Aluminas and Related Supported Reagents by Scanning Electron Microscopy
Authors: Ando Takashi , Clark James H , Cork David G , Kimura Takahide 
Published: July 2006

Abstract
SEM of MF–aluminas (M=Na, K, and Cs, loaded at 2 mmol g−1 and dried at 90 °C/2.7 kPa), showed similar salt dispersions and surface morphologies, with salt clusters of ca. 1 μm diameter evident on the external surfaces. Less reactive, highly dried or highly loaded, reagents showed extensive surface crystallization. KCl–and KOH–aluminas showed the effect of anion basicity, giving greater clustering and surface destruction respectively.
Synthesis of 1,3,6,8-Tetrakis(dimethylamino)pyrene Having Low Oxidation Potential
Authors: Ueda Naomi , Sakata Yoshiteru , Misumi Soichi 
Published: July 2006

Abstract
1,3,6,8-Tetrakis(dimethylamino)pyrene (1) was synthesized starting from the corresponding tetranitro compound. The first oxidation potential of 1 shows the lowest value (E1⁄21=−0.12 V vs SCE) among those of aromatic amines reported so far.
Electrochemical Properties of Adriamycin Adsorbed on Pyrolytic Graphite Electrodes Modified by Phospholipid Monomolecular Membranes
Authors: Konse Tomonori , Kano Kenji , Kano Rika , Kubota Tanekazu 
Published: July 2006

Abstract
Electrochemical equilibrium and kinetic parameters have been determined by means of numerical simulation of d.c. voltammograms based on the theory of a two-step surface-redox reaction for the case of the redox system of adriamycin adsorbed on a basal-plane pyrolytic graphite electrode (BPGE) which is modified by a phospholipid monomolecular membrane. Comparison of these parameters with those obtained at a bare BPGE has shown that thesemiquinone formation reaction is thermodynamically favorable and that the electron transfer rate constant decreases in these lipid membranes.
A Convenient One-Pot Synthesis of Acenaphthenequinones from 1-Acenaphthenones by NBS–DMSO Oxidation
Authors: Tatsugi Jiro , Okumura Shigeo , Izawa Yasuji 
Published: July 2006

Abstract
Acenaphthenequinone was obtained in 95% yield when the reaction of 1-acenaphthenone with N-bromosuccinimide was carried out in dimethyl sulfoxide at room temperature. Under similar conditions, several acenaphthenequinones were prepared from the corresponding 1-acenaphthenones in good yields.
The Structure of Diaquatris(1,1,1-trifluoro-2,4-pentanedionato)neodymium(III)–Acetone (1/1)
Authors: Nakamura Masao , Nakamura Reiko , Nagai Kiyofumi , Shimoi Mamoru , Tomoda Shuji , Takeuchi Yoshito , Ouchi Akira 
Published: July 2006

Abstract
The crystal and molecular structure of the title complex was determined by means of the singlecrystal X-ray diffraction method. The crystal of NdC18H22O9F9, F.W. 697.59, is orthorhombic, with a space group Pbna, a=22.068(5), b=22.293(4), c=11.020(2) Å, U=5421(2) Å3, Z=8, Dm=1.72(3), Dx=1.71 Mg m−3, and μ(Mo Kα)=20.46 cm−1. The central metal atom is octa-coordinated, being ligated with six β-diketonato and two water oxygen atoms, and is in a dodecahedral geometry. Two configurational isomers co-exist in the crystal, with the respective occupancy factors of 74 and 26%. In these isomers, the two chelate rings span in different ways; although the positions of all ligating oxygen atoms are the same, the chelates span two m-edges in one isomer and two g-edges in the other one.
Synthesis of New 1-Alkoxycarbonylamino-3-sulfonylpyrroles by Reaction of (Alkoxycarbonylazo)alkenes with β-Keto Sulfones
Authors: Attanasi Orazio , Filippone Paolino , Mei Amedeo , Santeusanio Stefania , Serra-Zanetti Franco 
Published: July 2006

Abstract
A mild, simple, and direct method for the synthesis of some new 1-alkoxycarbonylamino-3-sulfonylpyrrole derivatives by reaction of (alkoxycarbonylazo)alkenes with β-keto sulfones is reported.
Molecular and Crystal Structure of an Azobenzene-Linked Amphiphile, C33H54N3O3Br
Authors: Okuyama Kenji , Watanabe Hitoshi , Shimomura Masatsugu , Hirabayashi Kiyoshi , Kunitake Toyoki , Kajiyama Tisato , Yasuoka Noritake 
Published: July 2006

Abstract
Azobenzene-linked, single-chain ammonium amphiphile (C12AzoC5N+Br−), C33H54N3O3Br, was crystallized from their solutions in water and ethanol. The crystals are triclinic with the space group P\bar1, Z=2, a=3.4243(6), b=0.8525(1), c=0.6073(1)nm, α=73.45(1), β=88.03(1), and γ=93.32(1)°. The structure was solved by the direct method and refined anisotropically by the block-diagonal least-squares procedure: R=0.06 for 2917 observed reflections (2θ&lt;105°, Cu Kα, λ=0.154184 nm). The crystal structure consists of regularly stacking bimolecular layers in which C12AzoC5N+Br− molecules incline about 30° to the layer surface. As expected from spectroscopic analyses, the azobenzene chromophore shows a head-to-tail (J-like) aggregation between adjacent molecules. The pronounced planarity of the azobenzene chromophore found in this crystal structure enables parallel stacking of phenyl groups in the J-like aggregation.
Fluorescence and Nonradiative Relaxation from Vibronic Levels of S1 Pyrimidine: Effects of Molecular Rotation and Intramolecular Vibrational Redistribution
Authors: Sekiguchi Osamu , Ohta Nobuhiro , Baba Hiroaki 
Published: July 2006

Abstract
Emission characteristics of pyrimidine vapor which were measured after excitation into various S1 vibronic levels with relatively low excess vibrational energies (ΔE) below 2650 cm−1 were found to depend markedly upon ΔE. The emission from a vibronic level with ΔE&lt;1000 cm−1 (e.g., 6a1 or 11) is sharp and attributable to the fluorescence from the initially prepared vibronic level (IPL), and that from a vibronic level with ΔE&gt;1000 cm−1 (e.g., 121, 6a2, or 122) involves broad fluorescence besides the IPL fluorescence. At low pressure, the broad fluorescence consists of fast and slow components with lifetimes comparable to those for the corresponding components of the IPL fluorescence. The broad fluorescence exhibits another slow component which is characterized by a less tendency to undergo collisional quenching. The quantum yield of the slow component of the IPL fluorescence clearly depends upon molecular rotation, whereas that of the broad fluorescence appears to show little or no rotational-level dependence. On the basis of these observations, the broad fluorescence is assigned to the one originating from S1 vibronic levels that can be reached directly from the IPL through intramolecular vibrational redistribution (IVR) or indirectly via triplet levels. There exists no evidence to show that the IVR is affected by molecular rotation.
129I Mössbauer Spectroscopic Studies of Tetrathiafulvalene–Iodine Charge-Transfer Salts
Authors: Sakai Hiroshi , Mizota Manabu , Maeda Yutaka 
Published: July 2006

Abstract
The Mössbauer effect of 129I has been applied to investigate tetrathiafulvalene–iodine (TTF–In) charge-transfer salts at 16 K. The electrically conductive TTF–I0.71 salt shows a broad single-line with the isomer shift of −0.36 mm s−1, suggesting that the iodine atoms on the average are not completely ionic (I−1.0) but are negatively charged by about 0.9 (I−0.9) in the low temperature phase. This is due to the weak interactions of the iodine atoms with the sulfur atoms of the TTF molecules. This fact is consistent with the crystallographic data and the electron spin resonance spectra of the salt. This salt is recognized as a partially oxidized mixed-valence compound. The spectrum of the TTF–I3 salt consists of two sets of quadrupole octets, corresponding to the central and terminal iodine atoms of the slightly distorted I3− ion. The charge density localized on each iodine atom of the I3− ion is close to that of the isolated I3− ion. That is, the salt is regarded as a simple ionic compound, for which a high electrical conductivity can not be expected. It is confirmed that a small amount of the TTF–I2 salt coexists in the TTF–I0.71 phase obtained from the solution of excess TTF and iodine. In the salt the iodine atoms exist as polyiodides consisting predominantly of I3− units.
High-Temperature Reaction of NH3–N2O System in Shock Waves
Authors: Fujii Nobuyuki , Uchida Syuji , Sato Hisaaki , Fujimoto Shiro , Miyama Hajime 
Published: July 2006

Abstract
The high-temperature reaction of NH3 with N2O in shock waves was investigated by measuring ultaviolet absoption of NH3 and OH, and infrared emission of N2O, in the temperature range of 1700–2300 K on the mixture of NH3–N2O diluted with large amount of argon. A comparison of the observed decays of NH3 and N2O and the formation of OH with those obtained by computer simulation behind the incident shock wave was carried out. From the comparison, the rate constants of the following elementary reactions were determined: NH3+O→NH2+OH[k4=1012.5exp(−25.5 kJ⁄RT) cm3 mol−1 s−1]; NH3+OH→NH2+H2O[k5=1012.5exp(−8.4 kJ⁄RT) cm3 mol−1 s−1].
X- and Q-Band ESR Studies of Binuclear Copper(II) Complexes with 3-Alkyl-2-pyridone Bridging Ligands
Authors: Goodgame David M L , Nishida Yuzo , Winpenny Richard E P 
Published: July 2006

Abstract
The ESR spectra of polycrystalline samples of bis(N,N-dimethylformamide)tetrakis(3-ethyl-2-pyridonato)dicopper(II) and its 3-methyl-2-pyridone analogue have been measured at X-band (≈9.5 GHz) and Q-band (≈34 GHz) frequencies. The spectra are characteristic of S=1 species and the parameters (gz 2.30, gxy 2.05 and D≈0.29 cm−1) are discussed in terms of the known binuclear structure.
The Precipitation of Monodispersed α-Iron(III) Oxide Particles from Iron(III) Chloride–Glycine System in Aqueous and 2-Propanol/Water Media
Authors: Hamada Shuichi , Niizeki Shin , Kudo Yoshiyuki 
Published: July 2006

Abstract
Monodispersed α-iron(III) oxide (hematite) particles were prepared by aging iron(III) chloride solutions in the presence of glycine at elevated temperatures, 98–100 °C. An aqueous solution of glycinatoiron (III) complex directly gave monodispersed double spheres of hematite, ≈4 μm in size, under the specified conditions, for example, 2.0×10−2 mol dm−3 FeCl3, 0.60 mol dm−3 glycine, and 0.46 mol dm−3 HCl for 96 h. The hematite particles grew up through the polynuclear layers mechanism. By the forced hydrolysis in 2-propanol/water mixed solution of 30% by volume, monodispersed cuboidal hematite particles, 0.06–0.43 μm in size, were also obtained through the conversion of β-iron(III) hydroxide oxide previously deposited. The nucleation rate was markedly affected by acidity at the latter case. The formation processes of these monodispersed hematite particles are discussed.
Interfacial Phenomena in the Extraction Kinetics of Nickel(II) with 2′-Hydroxy-5′-nonylacetophenone Oxime
Authors: Watarai Hitoshi , Takahashi Manabu , Shibata Kiyoji 
Published: July 2006

Abstract
The interfacial adsorption of (E)-2′-hydroxy-5′-nonylacetophenone oxime and its role in the extraction kinetics of the nickel(II) ion with the oxime were investigated in heptane/aqueous phase systems by means of a high-speed stirring apparatus. The interfacial oxime concentration was correlated to the organic phase concentration, obeying the Langmuir isotherm. The interfacial activity of the oxime was also measured by means of interfacial tension measurements. The initial extraction rate of nickel(II) ion was linearly proportional to the interfacial concentration of the oxime (rather than to the bulk-phase concentration), to the nickel-ion concentration, and inversely to the hydrogen-ion concentration. These results supported the mechanism that the rate-determining step in the extraction is the 1:1 complex formation at the interface.
The Photochemical Formation of the π-Cation Radical from Chloro(5,10,15,20-tetraphenylporphyrinato)cobalt(III) in Aerated Dichloromethane
Authors: Yamamoto Kiyoko , Hoshino Mikio , Kohno Masahiro , Ohya-Nishiguchi Hiroaki 
Published: July 2006

Abstract
Chloro(5,10,15,20-tetraphenylporphyrinato)cobalt(III), CoIII(tpp)Cl, in an aerated dichloromethane(DCM) solution undergoes photooxidation to produce the porphyrin π-cation radicals, CoIII(tpp)+·Cl2. The formation mechanism of the π-cation radical was investigated by means of optical absorption and ESR spectroscopy: CoIII(tpp)Cl in DCM decomposes photochemically to yield CoII(tpp) and chlorine atoms, which then abstract hydrogen atoms from DCM molecules to yield solvent radicals, ·CHCl2, and HCl. The solvent radicals react with oxygen molecules, resulting in the generation of peroxyl radicals, which then oxidize CoIII(tpp)Cl to produce the π-cation radicals, CoIII(tpp)+·Cl2.
Regio- and Stereochemistry of Bromochlorinations of Alkynes with Molecular Bromine Chloride and Dichlorobromate(1−) Ion
Authors: Negoro Takeshi , Ikeda Yoshitsugu 
Published: July 2006

Abstract
The bromochlorination of phenyl- and alkyl-substituted acetylenes with tetrabutylammonium dichlorobromate(1−) (1) in dichloromethane was found to be anti-stereospecific and nonregiospecific (regiospecific in the case of phenylacetylene). Whereas the addition of molecular bromine chloride (2) to phenyl-substituted acetylenes was found to give nonstereospecific and regiospecific adducts, the reaction of alkyl-substituted acetylenes gave anti-stereospecific and nonregiospecific adducts. These results suggest that the addition of 1 involves an attack of chloride ion to a three-centered π-complex in the product-forming stage, and that the addition of 2 to phenyl-substituted acetylenes involves a vinyl cation intermediate (but a bridged bromonium ion intermediate in the case of alkyl-substituted acetylenes).
Bromochlorination of Alkenes with Dichlorobromate(1−) Ion. V. Regio- and Stereochemistry for the Bromochlorination of Styrene Derivatives with Dichlorobromate(1−) Ion in Protic Solvents
Authors: Negoro Takeshi , Ikeda Yoshitsugu 
Published: July 2006

Abstract
The bromochlorination of styrene derivatives with tetrabutylammonium dichlorobromate(1−) (1) in such protic solvents as acetic acid and methanol gives the corresponding bromo chloro adducts along with substantial amounts of solvent-incorporated products in a regiospecific manner (regioselective in the case of 3-nitro- or 2-chlorostyrenes). The reaction of 1-phenylpropenes with 1 gives nonstereospecific but regiospecific adducts. These results suggest that the addition of 1 to styrene derivatives in protic solvents involves an attack of chloride ion or solvent molecule to a bromonium ion intermediate.
Synthetic Approach toward Antibiotic Ezomycins. II. Synthesis of 5-Amino-3,7-anhydro-5-deoxyoctofuranose-(1,4) Derivatives
Authors: Sakanaka Osamu , Ohmori Takashi , Kozaki Shuji , Suami Tetsuo 
Published: July 2006

Abstract
A conversion of 5-acetamido-5-deoxy-1,2:7,8-di-o-isopropylidene-3-o-methylthiomethyl-β-l-erythro-d-allooctofuranose-(1,4) and -l-talooctofuranose-(1,4) to 5-amino-3,7-anhydro-5-deoxyoctofuranose-(1,4) derivatives has been investigated as a preliminary study for a synthesis of the octose moiety of ezomycins.
Infrared C–D Stretching and 2H NMR Spectra of Isopropyl-2-d 1-(p-Substituted Phenyl)ethyl Ketones. Evidence for the Hydrogen Bond-Like Interaction between C–D Group and Aromatic π-Electrons
Authors: Karatsu Makoto , Suezawa Hiroko , Abe Kazuhisa , Hirota Minoru , Nishio Motohiro 
Published: July 2006

Abstract
Isopropyl-2-d 1-(p-X-phenyl)ethyl ketones (where, X=H, NO2, Br, Cl, C2H5, CH3, and NH2) were shown to have two absorption bands in the C–D stretching region. The absorption band at the higher frequency (ca. 2177 cm−1) is assigned to the C–D···π approached conformer, and the high frequency shift is ascribed to the effect of steric compression. Weak C–D···π hydrogen bond was shown to occur by the measurement of the substituent effect on the formation constant and the relative enthalpy of the C–D···π approached conformer.