bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mass Transfer and Product-Selectivity in Electroreduction of p-Methylbenzaldehyde
Authors: Cheng Po-Chung , Nonaka Tsutomu 
Published: July 2006

Abstract
Mass transfer coefficients estimated from the formation ratio of the hydrodimeric to hydromonomeric products in electroreduction of p-methylbenzaldehyde in parallel plate electrode–flow cell and rotating cylinder electrode–beaker cell systems were shown in good agreement (less than 8% difference) with those obtained by ordinary current–potential and concentration–time methods.
Extended X-Ray Absorption Fine Structure Studies on Local Structure in Amorphous LaNi5.0 Films
Authors: Suenobu Tomoyoshi , Sakaguchi Hiroki , Tsuji Takaharu , Kanai Hiroyoshi , Yoshida Satohiro , Adachi Gin-ya 
Published: July 2006

Abstract
Analyses of the local structure around La and Ni atoms in amorphous LaNi5.0 films have been performed using the extended X-ray absorption fine structure (EXAFS), and the effect of the structure on the difference of hydrogen absorption characteristics between the amorphous and crystalline LaNi5.0 has been elucidated. The lengthening of interatomic distances for the Ni–Ni and La–Ni pairs, respectively, was observed for the amorphous samples in comparison with the crystalline ones. A part of the hydrogen sites existed in the crystalline LaNi5.0 was distorted in the amorphous one. Since the hydrogen atoms appear to be difficult to enter these sites distorted, the hydrogen content in the amorphous LaNi5 is smaller than that in the crystalline one.
Reactions of 1,1-Disubstituted Alkenes with Acetoacetamides and Molecular Oxygen in the Presence of Manganese(III) Acetate
Authors: Qian Chang-Yi , Nishino Hiroshi , Kurosawa Kazu 
Published: July 2006

Abstract
The reactions of 1,1-disubstituted ethenes with acetoacetamide or N-substituted acetoacetamides, and molecular oxygen in the presence of manganese(III) acetate gave a mixture of c-4- and t-4-carbamoyl-3-methyl-1,2-dioxan-r-3-ols in good yields. Effects of substituents in the alkenes as well as in the carbamoyl group in the acetoacetamides were observed. Stereochemistry and the reactivity of the 4-carbamoyl-3-methyl-1,2-dioxan-3-ols are discussed.
Selective Mono- and Bis(alkoxycarbonylation)s of Olefins Catalyzed by Palladium in the Presence of Cu(I) or Cu(II) Chloride under Remarkably Mild Conditions. Application to the Synthesis of γ-Butyrolactone Derivatives
Authors: Toda Shiho , Miyamoto Masanori , Kinoshita Hideki , Inomata Katsuhiko 
Published: July 2006

Abstract
Palladium-catalyzed mono- and bis(alkoxycarbonylation)s of olefins were controlled by the use of copper(II) and copper(1) chloride, respectively, in alcohol under normal pressure of carbon monoxide and oxygen at room temperature without any other additives. 3-Buten-1-ols gave the corresponding γ-butyrolactones and 2-oxotetrahydrofuran-3-acetic acid esters, respectively, in high yields.
Laser-Induced Organic Transformation. Direct and Selective Synthesis of Diols from Methanol, Ethanol, and Their Mixture in the Presence of Hydrogen Peroxide
Authors: Shimizu Yuichi , Sugimoto Shun’ichi , Kawanishi Shunichi , Suzuki Nobutake 
Published: July 2006

Abstract
The laser-induced transformation of methanol (MeOH), ethanol (EtOH), and MeOH–EtOH mixture have been investigated in the presence of H2O2. Ethylene glycol (EG) was highly selectively produced in high quantum yield (φ=0.94) by KrF-laser irradiation of the N2-saturated MeOH and the selectivity was 94% at 3.2 ml h−1 of H2O2 feeding rate (f). Butanediol (BD) and acetaldehyde (AA) were directly and selectively produced by KrF-laser irradiation of the N2-saturated EtOH. The quantum yields of BD and AA were 0.42 and 0.29, respectively, and the combined selectivity was 97% at f=3.4 ml h−1. Also, propanediols (PD) were directly produced by KrF-laser irradiation of the N2-saturated MeOH–EtOH mixture. The quantity of 1,2-PD reached the maximum at about 64 mol% of MeOH content. EG is produced through the dimerization of hydroxymethyl radicals formed by the abstraction of a hydrogen atom from MeOH by hydroxyl radical formed in high density by the laser-photolysis of H2O2. Similarly, 2,3-BD is produced by the dimerization of 1-hydroxyethyl radicals formed by the abstraction of α-hydrogen atom from EtOH by hydroxyl radical and 1,2-PD is produced by the recombination between hydroxymethyl radical and 1-hydroxyethyl radical.
Study of Various Factors Affecting the Stability of Ternary Cu(II) and Ni(II) Complexes
Authors: Ullah Mohammd Rafiqe , Bhattacharya Pabithrak K 
Published: July 2006

Abstract
The stability constants of the ternary M(II) complexes [MAL], where M(II) refers to Cu(II) and Ni(II), A refers to 2,6-pyridinedicarboxylic acid (dpa) and iminodiacetic acid (imda) and L refers to glycine, α-alanine, phenylalanine, tyrosine, tryptophan, ethylenediamine, 1,3-propanediamine, oxalic acid, catechol, catechuic acid, tiron, pyrogallol, o-aminophenol, and o-phenylenediamine, have been determined potentiometrically by using SCOGS computer programme. Probable reasons for less negative ΔlogK values of the ternary complexes have been discussed.
Acid-Base and Complex-Formation Properties of N-Hydroxy-3-pyridinecarboxamide and N,2-Dihydroxybenzamide in Aqueous Solution
Authors: Leporati Enrico 
Published: July 2006

Abstract
The protonation and complexation equilibria of the iron(III) and copper(II) complexes of N-hydroxy-3-pyridinecarboxamide (hpca) and N,2-dihydroxybenzamide (dhbc) have been investigated by potentiometric and spectrophotometric techniques in 0.5 mol dm−3 (KCl) at 25±0.1°C. It was shown that the properties of iron(III) and copper(II) chelates under study are similar to those of corresponding chelates of simple aromatic hydroxamic acids (without any additional donor groupings in the molecule). The hydroxamate and carbonyl oxygens may also take part in coordination in the copper(II) and iron(III) systems.
Correlation between Physicochemical Characteristics of Synthetic Cationic Amphiphiles and Their DNA Transfection Ability
Authors: Akao Tetsuyuki , Osaki Tetsurou , Mitoma Jun-ya , Ito Akio , Kunitake Toyoki 
Published: July 2006

Abstract
Liposomes formed with synthetic double-chain ammonium amphiphiles were used for DNA transfection into eukaryotic cells. We studied the correlation between the efficiency of various cationic amphiphiles in DNA transfection and their physicochemical properties. The efficiency of amphiphiles in the transfection was examined by the transient expression of β-galactosidase from its cDNA in COS cells. Amphiphiles with a phase-transition temperature (Tc) lower than 37°C, as measured by differential scanning calorimetry, could introduce DNA into the cells. Electron microscopic observation indicated that amphiphiles possessing DNA transfection ability form vesicular structures in aqueous solution. Thus, fluid and vesicular bilayer structures were much higher than rigid and helical bilayer structures regarding the effectiveness of amphiphiles in DNA transfection. The efficiency of didodecyl N-[p-(2-trimethylammonioethoxy)benzoyl]-l-glutamate bromide was the highest of all the synthetic amphiphiles examined.
The Claisen Rearrangement of 2-Phenylsulfinyl-2-propenyl Phenyl Ethers –A New Route to Functionalized Phenols and 2-Methylbenzofurans
Authors: Khan Muhammad Akram 
Published: July 2006

Abstract
The hitherto unknown Claisen rearrangement of 2-phenylsulfinyl-2-propenyl phenyl ethers to the corresponding 2-(2-phenylsulfinyl-2-propenyl)phenols is reported. The latter compounds underwent Michael reactions with a variety of nucleophiles to provide functionalized phenolic adducts. O-Alkylation of the initial rearrangement products with 3-bromo-2-phenylsulfinyl-1-propene and 2,3-dibromo-l-propene followed by [3,3] sigmatropic rearrangement provided a promising route to 7-substituted 2-methylbenzofurans.
Kinetic Studies on the Chemical and Electrochemical Reduction of Some 4-Arylidene-5-pyrazolone Compounds
Authors: Abdel-Rahman Mahmoud A , Abdel-Hamid Refat , Rabia Mostafa K , El-Dessouki Mohamed M 
Published: July 2006

Abstract
Kinetics of chemical and electrochemical reduction of some 4-arylidene-5-pyrazolones were studied. The chemical reduction was performed using aluminum hydride. The electrochemical reduction in 0.1 mol dm−3 TEAP/DMF was studied by cyclic and convolution potential sweep voltammetry at HDME. The title compounds exhibit two diffusion-controlled irreversible mono electronic cv waves. Both waves follow EC kinetics and they are attributed to the reduction of the pyrazolin carbonyl group. The kinetics of the chemical and electrochemical reduction were proposed and discussed in terms of the molecular structure of the subject arylidenes.
Asymmetric Diels–Alder Reactions of an Acrylic Acid Derivative Using a Chiral Titanium Catalyst
Authors: Narasaka Koichi , Tanaka Hiroko , Kanai Fumihiko 
Published: July 2006

Abstract
Asymmetric Diels–Alder reactions of an acrylic acid derivative using a catalytic amount of a chiral titanium reagent were performed with several dienes. The titanium catalyst was prepared by the alkoxy exchange between dichlorodiisopropoxytitanium(IV) and a chiral 1,4-diol derived from (2R,3R)-tartrate. By the use of the titanium catalyst, the reaction between 3-acryloyl-1,3-oxazolidin-2-one and dienes proceeded in a toluene–petroleum ether mixture in the presence of Molecular Sieves 4A to afford the Diels–Alder adducts in 72–100% yields and 88–&gt;96% enantioselectivity. This reaction can be applied to a diene containing a hetero atom such as 2-ethylthio-1,3-butadiene, which affords the Diels–Alder adduct in a high optical purity. In this paper are also described the methods for determining the optical purities of the obtained 4-substituted 3-cyclohexenecarboxylic acid derivatives.
Different Kinetic Behavior of Zinc(II), Cadmium(II), and Lead(II) Porphyrins in the Ligand-Substitution Reaction with Ethylenediaminetetraacetic Acid
Authors: Tabata Masaaki , Suenaga Kazuhisa 
Published: July 2006

Abstract
Kinetics and mechanism of the ligand-substitution reaction of Zn-, Cd-, and Pb(tpps)4− (H2tpps4−=5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin) with ethylenediaminetetraacetic acid (EDTA) have been studied at 25°C and I=0.1 mol dm−3 (NaNO3). The rate equation for the decrease of M(tpps)4− is expressed as –d[M(tpps)4−]⁄dt=(k1[edta4−])+k2[Hedta3−]+k3k4[H]2(k−3+k4[H+])−1)[M(tpps)4−], where M=Zn2+, Cd2+, and Pb2+, and edta4− denotes the fully deprotonated form of EDTA, respectively. The values of k1 were found to be 0 for all of the metalloporphyrins studied, and k2=0 mol−1 dm3 s−1; k3k4(k−3)−1=8.7±0.2 mol−2 dm6 s−1 for Zn(tpps)4−, k2=4.1±0.2 mol−1 dm3 s−1; k3k4(k−3)−1=(8.3±0.4)×1012 mol−2 dm6 s−1 for Cd(tpps)4− and k2=2.0±0.1 mol−1 dm3 s−1; k3(5.4±0.1)×107 mol−1 dm3 s−1; k3k4(k−3)−1=2.0±0.1 mol2 dm6 s−1 for Pb(tpps)4−, respectively. Hedta3− directly attacks Cd- or Pb(tpps)4 to form its metal complex, whereas Hedta3− can not bind Zn(tpps)4−. Zn(tpps)4− dissociates to aquazinc(II) by proton attack, then the aquazinc(II) reacts with Hedta3. Therefore, the ligand-substitution reaction of Zn(tpps)4− with EDTA is so slow that the reaction can be negligible compared with those of Cd- and Pb(tpps)4− in an alkaline solution. The reaction mechanism of the ligand substitution reaction and the different reactivities of the metalloporphyrins in it are discussed in detail.
1,3-Diol Fragmentation Using a Reactive Benzylic Hydroxyl Group as a Nucleofuge. Synthesis of a Tobacco Sesquiterpene
Authors: Kato Michiharu , Tooyama Youichi , Yoshikoshi Akira 
Published: July 2006

Abstract
A benzylic hydroxyl group activated by electron-donative aromatic function was found to be a remarkably reactive nucleofuge for 1,3-diol fragmentation. Thus, treatment of α-(2,6-dimethoxy-4-methylphenyl)-2β-hydroxy-2α,5,5,8aβ-tetramethyl-4aα-decahydro-lβ-naphthalenemethanol with pyridinium chloride or pyridinium p-toluenesulfonate in dichloromethane underwent the 1,3-diol fragmentation smoothly to produce r-1-[(E)-2-(2,6-dimethoxy-4-methylphenyl)ethenyl]-t-2-(3-oxobutyl)-1,3,3-trimethylcyclohexane (24) in quantitative yield. Starting from 24, a tobacco sesquiterpene, 4-(2,2,6-trimethyl-6-vinylcyclohexyl)-2-butanone, was synthesized in racemic form by seven steps.
Limiting Partial Molar Volumes of Ions in Water–Methanol and Water–Acetonitrile
Authors: Kawaizumi Fumio , Inoue Yoshitomo , Nomura Hiroyasu 
Published: July 2006

Abstract
Measurements of densities of solution of AgNO3 and Ca(NO3)2 in the mixed solvents water–methanol and water–acetonitrile were carried out at 25°C and the partial molar volumes V2∞ of these electrolytes were determined by taking account of the concentration dependence of the apparent molar volumes predicted by the Debye–Huckel theory. The ionic partial molar volumes of Ag+, Ca2+, and NO3− were evaluated and compared with those of other ions in the two mixed solvent systems. The solvent composition dependence is more remarkable in water–acetonitrile than in water–methanol, and characteristic behavior was observed for Ag+ and Ca2+ ions in water–acetonitrile system.
Synthesis and Inclusion Properties of Sulfur-Bridged Analogs of Acyclic Phenol-Formaldehyde Oligomers
Authors: Ohba Yoshihiro , Moriya Kazuhiko , Sone Tyo 
Published: July 2006

Abstract
A series of compounds in which a part or all of the methylene bridges of acyclic p-methyl- and p-t-butylphenol–formaldehyde tetramers were replaced by sulfur bridge(s) was synthesized. It was found that though the sulfur-bridged tetramers formed crystalline host-guest complexes with a variety of organic compounds, they were different from the parent tetramers regarding their inclusion behavior. The number and position of the sulfur bridge(s), as well as the p-substituent of phenol in the tetramers, had a great influence upon the inclusion property. The thermal stability of complexes of the sulfur-bridged tetramers (SSS-a,b) with benzene, as estimated from their thermal dissociation rates, are lower than those of the parent tetramers (CCC-a,b).
On the Partitioning of the NMR B′-Coefficient. The Evaluation of Single Ion B′-Coefficients by a New Method and the Correlation with the Viscosity B-Coefficient, Partial Molal Volume and Electrostatic Entropy of Solvation of Ions in Aqueous and Nonaqueous Systems
Authors: Bhattacharyya Moni Mohan 
Published: July 2006

Abstract
A new method of division used for the viscosity B-coefficient has now been extended to the partitioning of the NMR B′-coefficient both in aqueous and various nonaqueous systems. The derived set of Bi′-values, unlike those obtained by other methods in water are found to be quantitatively related to the ionic molal volumes obtained by the UVP method. The usual assumption of equal contributions of K+ and Cl− ions has been discarded. Abraham et al.’s electrostatic entropy of solvation of ions has also been found to give excellent linear correlation with the derived NMR Bi′-values in different solvents. The striking feature is that the NMR Bi′-values as derived by Abraham and coworkers by a different method are almost identical to the present values in all the nonaqueous solvents studied. The slight disagreement observed for the aqueous system has been discussed as being due to encroaching of the disordered second layer to the first layer of solvation, thereby making the absolute entropy estimates less certain. Both the cationic and anionic Bi′-values are represented by a single smooth parabolic curve against the crystal ionic radii as predicted by the theory. The hydration number for Cl− ion as derived from this work agrees excellently with the widely accepted value.
Voltammetric Studies on Some Arylhydrazones of α-Cyano Ketones and α-Cyano Esters
Authors: Abou-Elenien G M , Ismail N A , Hafez T S 
Published: July 2006

Abstract
The redox characteristics of the title compounds are extensively studied using DC-, cyclic voltammetry, coulometry, and controlled potential electrolysis in benzonitrile at platinum electrodes. These compounds are oxidized in one-electron transfer process followed by deprotonation which leads to dimerization. The reduction process differs according to the nature of the compound and the electron-withdrawing power of the substituent in the α-position. They can be reduced in a single two electron or two one electron waves leading in both cases to saturation of the hydrazonic moiety.
Separation of Scandium(III) as Ascorbato Complex by Extraction with Aliquat 336S
Authors: Karve M A , Khopkar S M 
Published: July 2006

Abstract
Scandium was quantitatively extracted with 0.1 mol dm−3 Aliquat 336S in xylene at pH=6.0 from 0.01 mol dm−3 ascorbic acid. It was stripped with l mol dm−3 hydrochloric acid and determined as its complex with Arsenazo III. It was separated from binary mixtures by exploiting the difference in the extraction behavior from ascorbic acid. Several separations were accomplished by process of selective stripping with concentrated hydrochloric acid. Many interesting separations of scandium from associated elements like yttrium, thorium, uranium, and molybdenum have been carried out.
Synthesis of Dimethylsilyl Bis-Enol Ethers Derived from Aldehydes
Authors: Fataftah Z A , Ibrahim M R , Abdel-Rahman H N 
Published: July 2006

Abstract
Two procedures for the prepation of dimethylsilyl bis-enol ethers from aldehydes, through enolization, are described. Dimethylsilyl bis-enol ethers, derived from propanal, butanal, 2-methylpropanal, pentanal, hexanal, and heptanal have been synthesized by refluxihg a mixture of triethylamine, dichlorodimethylsilane and the corresponding aldehyde in tetrahydrofuran for 18–38 h. The yields are in the range of 75–90%. Alternatively, a stronger base, lithium 2,2,6,6-tetramethylpiperidide (LiTMP) is used for deprotonation of the above mentioned aldehydes at −23°C. The enolates are then quenched with dichlorodimethylsilane. The small aldehydes, propanal, butanal, and 2-methylpropanal fail to give the desired products, while the others gave a very good yields (56–85%). Ethanal fails to give the product in either of the two procedures. A competitive rate of polymerization with the rate of proton abstraction or with the rate of mixing of the reactants could explain these failures. The silyl bis-enol ethers have been characterized on the basis of their NMR, IR, and elemental analysis data.
Synthesis and Aldol Stereoselectivity of 2-Oxazolidinones Derived from l-Histidine
Authors: Bermejo Gonzalez Francisco , Perez Baz Julia , Santinelli Fabio , Mayor Real Fernando 
Published: July 2006

Abstract
The regiospecific synthesis of the 2-oxazolidinones 5b, 7, 12a, and 12b starting from l-histidine la is described. The stereoselectivity in the dibutyl(trifluoromethylsulfonyloxy)borane promoted aldol condensation between the chiral imides 13a and 13b and benzaldehyde was also studied. The formation of a cationic imidazole–boron complex, 14a, occurs before the aldol condensation between 13a and benzaldehyde takes place. However, the condensation between 13b and benzaldehyde occurs without the formation of any boron complex. The steric hindrance of the substituent at C-4 may account for this difference in behavior.
Sulfur Nitride in Organic Chemistry. Part 19. Selective Formation of Benzo- and Benzobis[1,2,5]thiadiazole Skeleton in the Reaction of Tetrasulfur Tetranitride with Naphthalenols and Related Compounds
Authors: Mataka Shuntaro , Takahashi Kazufumi , Ikezaki Youji , Hatta Taizo , Tori-i Akiyoshi , Tashiro Masashi 
Published: July 2006

Abstract
Tetrasulfur tetranitride (N4S4) reacted with 2-naphthols to afford naphtho [1,2-c][1,2,5] thiadiazoles (13) in high yields, while 1-naphthaols gave naphtho[1,2-c:3,4-c′]bis[1,2,5]thiadiazoles as a major product, together with a small amount of 13. In the reactions with naphthalenediols such as 1,5-, 2,6-, 2,7-, 1,6-, and 1,7-diol, naphtho[1,2-c:5,6-c′]- or naphtho[1,2-c:7,8-c′]bis[1,2,5]thiadiazoles were obtained in varying yields. In some cases, naphtho[1,2-c:3,4-c′:5,6-c″]tris[1,2,5]thiadiazole was formed as a by-product. In reactions with 5-isoquinolinol, 8-quinolinoles, 9H-carbazol-2-ol, and dibenzofuran-2-ol, one and/or two 1,2,5-thiadiazole-ring-fused heteroaromatic compounds were obtained.
Theoretical Study on the Formation of Spherical Micelles
Authors: Funasaki Noriaki , Hada Sakae 
Published: July 2006

Abstract
From the Tanford theory for the formation of spherical micelles and a modification of this theory, the aggregation number nw and monomer concentration x1 are calculated as a function of total surfactant concentration x. The definition of cmc of d3x1⁄dx3=0 is adequate. Empirical equations for the estimation of nw and cmc are obtained.
Thermochromism of Metal Complexes of Cresolphthalein Dye. Solvent Effect on Temperature-Dependence and Reversibility
Authors: Nanasawa Masato , Wada Mitsuo , Kamogawa Hiroyoshi 
Published: July 2006

Abstract
The thermochromism of metal complexes of cresolphthalein dye was studied in organic solvents in the presence of pyridine derivatives. Remarkable thermochromic changes were observed for complexes with nickel(II) and magnesium(II) ion; a large temperature dependence was found in a polar aprotic solvent.
Revised Structure of 2-Cyclohexyl-3,4-diphenyl-1,2-oxaphosphetane 2-Oxide
Authors: Kawashima Takayuki , Nakayama Shigenobu , Yoshifuji Masaaki , Okazaki Renji , Inamoto Naoki 
Published: July 2006

Abstract
The correct structure of the title compound was elucidated to be cyclohexyl(2,2-diphenyl-1-hydroxy-ethyl)phosphine oxide, which seems to be formed via migration of a phenyl group, from the NMR spectral data and synthesis of the dimethyl derivative.
Gold(III) Complexes of 2-Amino-4,6-dimethylpyrimidine
Authors: Kovala-Demertzi Dimitra 
Published: July 2006

Abstract
The reactions of Au(III) with 2-amino-4,6-dimethyl pyrimidine (ADMPY) are reported. Complexes of Au(III) with ADMPY have been isolated from reactions in aqueous and in methanolic solutions, and characterized by elemental analysis, IR spectra 1H NMR spectra, electronic absorption spectra, conductivity in DMF solutions, and thermal gravimetric analysis.
A New Oxidizing System for Aromatic Alcohols by the Combination of N-Oxoammonium Salt and Electrosynthesized Tetraalkylammonium Tribromide
Authors: Inokuchi Tsutomu , Matsumoto Sigeaki , Fukushima Mitsuhiro , Torii Sigeru 
Published: July 2006

Abstract
A combination of 2,2,6,6-tetramethyl-1-piperidinyloxyl and tetraalkylammonium tribromides (R4NBr3), which are available from the corresponding tetraalkylammonium bromides via electrooxidation with potassium bromide, has proved to be useful for oxidations of primary and secondary alcohols to the corresponding aldehydes and ketones, respectively. The oxidation reaction proceeds smoothly even with a 0.5–1.0 mol% of N-oxyl compounds and 1.5–2.0 equivalents of tetraalkylammonium tribromides in an aqueous-organic two-phase solution buffered at pH 8.0–8.6. This recyclable oxidant/co-oxidant combination system may involve the formation of N-oxoammonium salts, actual oxidizing agents of alcohols, by the action of hypobromite species generated from R4NBr3 in the binary solution. Utility of the method is highlighted by the selective oxidation of benzylic alcohols bearing electron-releasing groups on the aromatic nucleus to the corresponding aldehydes or ketones without any bromination and overoxidation.
The Fifth Overtone Spectra of C–H Stretching Vibrations of C6H5X in Nonpolar Solvents
Authors: Itaya Kazuhiko , Nasu Takao , Sakai Jun , Katayama Mikio 
Published: July 2006

Abstract
The fifth overtone spectra of aryl C–H stretching vibrations of fluorobenzene, chlorobenzene, and bromobenzene in nonpolar solvents were observed using photoacoustic spectroscopy. In a nonpolar solvent, such as hexane, the three components of the overtones of the o-, m-, and p-C–H stretching vibrations could be easily decomposed owing to line-width narrowing. We could therefore obtain more detailed information concerning the chemical properties of these C–H bonds.