bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical and Magnetic Properties of Crystalline Phenothiazine Cation Radical Salts
Authors: Iida Yôichi
Published: July 2006

Crystalline phenothiazine cation radical salts show charge-transfer transition between cation radicals in the low-energy region. These salts have antiferromagnetic exchange interaction between cation radicals. Their optical and magnetic properties were discussed in terms of onedimensional Hubbard model.
Hydrogenation and Dehydrogenation of 4-Isopropenyl-1-methylcyclohexene Catalyzed by MgO, CaO, La2O3, ThO2, and ZrO2
Authors: Tanaka Yasutaka , Hattori Hideshi , Tanabe Kozo
Published: July 2006

4-Isopropenyl-1-methylcyclohexene undergoes hydrogenation over ZrO2 and ThO2 to 4-isopropyl-1-methylcyclohexene, while it undergoes mainly dehydrogenation over MgO, CaO, and La2O3 to 1-isopropyl-4-methylbenzene. The activity variation of catalysts with pretreatment temperature and the reaction of 4-isopropyl-1-methyl-1,3-cyclohexadiene suggest that selectivity is determined by relative activity for hydrogenation to that for double bond isomerization.
Nitric Acid Oxidation of 3,5,7,7,10,12,14,14-Octamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-dienenickel(II) Perchlorate
Authors: Ito Tasuku
Published: July 2006

Oxidative dehydrogenation of three kinds of the title compounds, meso[1R(S), 3S(R), 8S(R), 10R(S)]-, rac[1S(R), 3R(S), 8S(R), 10R(S)]-, and optically active[1S, 3R, 8S, 10R]-forms produced the complexes with four isolated imine groups. Some spectroscopic data of the tetraimine complexes are presented.
Preparation of Shark Powder and Shark Paste as Biological Standard Reference Materials
Authors: Dokiya Yukiko , Kurosawa Satoru , Toda Shozo , Fuwa Keiichiro
Published: July 2006

As a possible biological standard reference material for metal analysis, shark powder has been prepared from the muscle of sharks (Squalus mitsukurii) and compared with shark paste which was prepared from the same raw material adopting the procedure of Japanese fish paste production. With respect to the homogeneity of metal contents and to the stability during storage, both samples were found to be similar.
Preparation and Properties of Cobalt(III) Complexes Containing meso-1,2-Diphenyl-1,2-ethanediamine
Authors: Kojima Masaaki , Ishiguro Momoyo , Fujita Junnosuke
Published: July 2006

Two new complexes, [Co(meso-dpen)3]3+ and [Co(NH3)4 (meso-dpen)]3+ have been obtained, where meso-dpen denotes meso(R,S)-1,2-diphenyl-1,2-ethanediamine. The former is stable in the solid state, but decomposes slowly in solution at room temperature, while the latter is stable in solution.
13C NMR Spectra of 4,6-O-Benzylidenehexopyranosides and Their 2,3-Di-O-sulfonate Derivatives
Authors: Sugiyama Hiroshi , Yamazaki Tatsumi , Senda Yasuhisa , Ishiyama Jun-ichi , Matsuda Kazuo , Seto Shuichi
Published: July 2006

13C NMR spectra of the title compounds were measured. The relationship between their chemical shifts and reactivity is discussed.
Oxidation of Thujopsene with Metal Acetate in Acetic Acid
Authors: Sekizaki Haruo , Ito Masaaki , Inoue Shoji
Published: July 2006

Thujopsene has been oxidized with lead tetraacetate, cobalt triacetate and manganese triacetate, to different kinds of products being 4β-acetyl-6β,10,10-trimethyltricyclo[4.4.0.01,3]decane (3) and its diacetate; 2β-acetoxymethyl-2α, 4aβ,8,8-tetramethyl- 2,3,4,4a,5,6,7,8-octahydronaphthalene (7) and widdryl acetate; 3, 7, and widdrol, respectively.
Reactions of Isomeric Transition-Activated 80Br in the H80mBr–CH4 System
Authors: Kondo Kenjiro , Yagi Masuo
Published: July 2006

The reaction of isomeric transition-activated 80Br was studied in the gaseous H80mBr–CH4(HBr/CH4=0.1±0.01) system. CH380Br, CH280BrBr and CH80BrBr2 were identified as the products, and their absolute yields were 1.60, 2.65, and 0.05%, respectively. The effects of Kr and Xe additives show that these products were produced only through kinetic-energy independent (thermal ionic) processes. The results are compared with those obtained in the 80mBrBr (or 82mBrBr)–CH4 system, in which the C–*Br formation proceeds mainly via kinetic-energy dependent processes, and the difference between them is explained on the basis of the cross sections for charge neutralization and capture collision complex formation of bromine ions as a function of the kinetic energies initially acquired by the 80Br and 82Br atoms. The persistent complex ion, CH480Br+, is considered to be a precursor of the product formations, and the formation of individual products is discussed on the basis of ion-molecule reactions of CH480Br+ with surrounding molecules. Furthermore, the effect of HCl and CH2=CH2 additives on the yield distribution were examined to elucidate the reaction mechanisms of the product formations.
ENDOR Relaxation Study of the Effects of Intramolecular Cation Migration on the Ion-pair System
Authors: Okazaki Masaharu , Kuwata Keiji
Published: July 2006

The ENDOR spectra of the ion-pair system of the 2,5-di-t-butyl-p-benzoquinone anion and the alkali metal cation in 1,2-dimethoxyethane were observed. The influence of the intramolecular cation migration on both the linewidth and the intensity of the ENDOR spectra was experimentally examined. The results obtained were discussed theoretically using the Kaplan-Alexander formula. The intramolecular exchange due to the cation migration was shown to be effective in ENDOR.
Barrier to Internal Rotation around the Isopropyl-Nitrogen Bond of Some N,N-Diisopropyl-1,3-dithia- and 1,3-diselenacycloalkan-2-iminium Salts, [X(CH2)nXCN(i-Pr)2]+Y− (X=S, Se; Y=Br, PF6; n=2,3)
Authors: Takeda Yu-ichi , Matsuda Tsuneo , Tanaka Toshio
Published: July 2006

Activation parameters for rotation around the isopropyl-nitrogen bond of the title compounds were determined by the line shape analysis of 1H NMR spectra. The Ea values lie in the ranges of 58–60 kJ/mol for X=S and 52–54 kJ/mol for X=Se. The activation parameters are little influenced by the ring size of the 1,3-diheteracycloalkane moiety and the counter anions.
Flash Photolysis Study on the Addition Reaction of Alkylthiyl Radical to Olefins
Authors: Ito Osamu , Matsuda Minoru
Published: July 2006

The transient absorption band appearing at 370 nm by flash photolysis of di-t-butyl dusilfide was assigned to the t-butylthiyl radical. Photolyses of the disulfide solutions containing olefins such as 1,1-diphenylethylene and styrene gave new transient bands in a wavelength region similar to that of the diphenylmethyl radical and benzyl radical, respectively. These new bands can be attributed to the radicals produced by the addition of the thiyl radical to olefins; (Ph)2\dotC–CH2–SR and H(Ph)C–CH2–SR. Kinetic studies including the addition of the thiyl radical to olefins were performed.
Temperature Effects on the Raman Intensity of Liquid Samples and an Averaged Molecular Field
Authors: Hatakeyama Haruo , Fujiyama Tsunetake
Published: July 2006

The relative Raman intensities of the v1 line of carbon tetrachloride, the v8 line of acetonitrile, and the v3 line of chloroform were observed in the liquid phase and at various temperatures. The apparent intensity change due to the temperature were explained in terms of the local field effect, the density change, the statistical distribution effect, and the contribution of transition hyperpolarizability in the presence of a non-zero averaged molecular field.
Ring Transformation of γ-Butyrolactone into γ-Thiobutyrolactone over Alkaline Cation Exchanged Zeolites
Authors: Hatada Kou , Takeyama Yoichi , Ono Yosho
Published: July 2006

The reaction of γ-butyrolactone and hydrogen sulfide to give γ-thiobutyrolactone over zeolites was studied. Alkaline cation exchanged zeolites have high catalytic activity for the ring conversion, acidic zeolites very low activity. γ-Thiobutyrolactone was obtained in 99% yield with CsY at 330 °C. There is no decay of catalytic activity with time. The reaction kinetics over LiY, NaY, and CsY are expressed by

r=\frack(aLPL)(aHPH)(1+aLPL+aHPL)2,

where r is the rate of reaction, PL and PH are the partial pressure of γ-butyrolactone and hydrogen sulfide, respectively, and k, aL, aH are constants. The activation energies for k are 39, 31, and 26 kcal mol−1 with LiY, NaY, and CsY, respectively. Catalytic activity is enhanced by addition of pyridine but almost completely depressed by addition of hydrogen chloride. It is concluded that basic sites play an important role in the ring transformation.
Effect of the Trap Density on Switching in Naphthacene Thin Films
Authors: Sadaoka Yoshihiko , Sakai Yoshiro
Published: July 2006

Switching phenomena were observed in Au(+)–naphthacene (crystalline-state)–Al(−). The threshold voltage was found to be expressable as Vth∝ (thickness)2; in amorphous films no reproducible switching phenomena were observed within the same region of the field strength. The differences between them were discussed in terms of the trap density, which is closely related to the crystallinity of the evaporated films.
Solid-phase Thermal Syntheses of Binuclear Chromium(III) and Cobalt(III) Complexes Containing N-(2-Sulfoethyl)iminodiacetic Acid
Authors: Kimura Masazo , Uehara Akira , Kyuno Eishin , Tsuchiya Ryokichi
Published: July 2006

The following four chromium(III) and cobalt(III) double complexes were prepared and the thermal reactions were investigated both isothermally and non-isothermally in the solid-phase: [(Cr or Co)(H2O)(NH3)5][(Cr or Co)(sida)2] where sida denotes N-(2-sulfoethyl)iminodiacetate ion. The double complexes were found to be thermally deaquated to form the homo- and hetero-metal binuclear complexes [(NH3)5(Cr or Co) (sida)(Cr or Co)sida)] in which one of N-(2-sulfoethyl)iminodiacetate ions functions as the bridging ligand between two metal ions. The complexes thus obtained were purified from a 50% HClO4 or a 1 M NaClO4 solution in the forms of the hydrogen salts [(NH3)5(Cr or Co)(sida) (Cr or Co)(sidaH)]ClO4 or the sodium salts [(NH3)5(Cr or Co)(sida)(Cr or Co)(sidaNa)]ClO4.
2.5 th Order Differential Electroanalysis
Authors: Goto Masashi , Hirano Takafumi , Ishii Daido
Published: July 2006

The theory which describes the properties of the 2.5th order derivative of current, e″, vs. the electrode potential, E, curves is presented in response to an imposed ramp signal on a stationary electrode. The 2.5th order differential, e″(t), of the current, i(t), is defined by

e″(t)≡\fracd2.5dt2.5i(t)=\fracd3dt3\left[\frac1√‾π∫0t\fraci(λ)√‾t−λdλ\ight].

The predicted dependences of peak height, peak potential, and peak width on concentration, electron number, and scan rate, etc. have been confirmed experimentally, using the analogue circuit to monitor the electroreductions of Cd2+, Pb2+, Tl+, Zn2+, and Ni2+ on a hanging mercury electrode. It was proved that the proposed technique adds the advantages of further higher resolution and higher sensitivity to those of semidifferential electroanalysis. At the scan rate of 100 mV/s, the signals observed in this technique were about 50 and 8 times larger than those in linear sweep voltammetry for the reductions of Cd2+ and Ni2+, respectively. Sufficient resolution was obtained for the qualitative analyses between Pb2+ and Tl+, between Ni2+ and Zn2+, and between Ni2+ and H+ at pH 1.4 in this technique.
The Analogs of Hofmann Type Clathrate Formed between Diammine-or Diaminemetal(II) Tetracyanometallate(II) Host and Aromatic Guest Molecule
Authors: Iwamoto Toschitake , Kiyoki Mamoru , Ohtsu Yutaka , Takeshige-Kato Yasuko
Published: July 2006

A novel series of clathrates Cd(tn)M′(CN)4·2G (M′=Cd or Hg; G=C4H4S, C4H5N, C6H6, or C6H5NH2) were prepared as an analogous series of Hofmann type clathrate. Including the novel series, Hofmann type and the analogous clathrates with a general formulation M(diam)M′(CN)4·2G were classified into five groups according to the combination of the host constituents and the resulting host framework structures as follows: Hofmann type M(NH3)2M′(CN)4·2G with square-planar M′(CN)4, Hofmann-en type Cd(en)NM′(CN)4·2G with ambident en and square-planar M′(CN)4, Hofmann-Td type Cd(NH3)2M′(CN)4·2G with tetrahedral M′(CN)4, en-Td type Cd(en)M′(CN)4·2G with ambident en and tetrahedral M′(CN)4, and tn-Td type Cd(tn)M′(CN)4·2G with ambident tn and tetrahedral M′(CN)4. Their structural features were discussed based on the flexibility of the framework whether it can enclathrate aniline as the largest guest or not.
Ion-Molecule Reactions in the Binary Mixture of Acetaldehyde and Trioxane. I. Hydrogen Atom and Proton Transfer Reactions
Authors: Kumakura Minoru , Arakawa Kazuo , Sugiura Toshio
Published: July 2006

The formation reactions of protonated molecular ions in acetaldehyde–trioxane mixtures have been studied with a modified time-of-flight mass spectrometer. From the analysis of the fine structure of the ionization efficiency curves of fragment and product ions obtained by means of the retarding potential differential technique using acetaldehyde-d4, the precursors of the product ions were determined. Protonated acetaldehyde is formed by the hydrogen atom transfer reaction of acetaldehyde molecular ion with trioxane, and protonated trioxane by the proton transfer reaction of CHO+ generated from acetaldehyde with trioxane. The rate constants of the formation reactions of the product ions in acetaldehyde (or ace taldehyde-d4)–trioxane mixtures were determined and isotope effect was observed. The CHO+ generated from acetaldehyde participated predominantly in the proton transfer reaction as compared with that generated from trioxane. From the proton transfer reaction involving thermal ion CHO+ generated from acetaldehyde it was found that the proton affinity of trioxane is smaller than that of acetaldehyde.
1-Allylpyrazole as a Ligaud. V. Preparation and Characterization of Some Iron(0) and Group VI Metal(0) Carbonyls
Authors: Fukushima Kazuo , Miyamoto Takeshi , Sasaki Yukiyoshi
Published: July 2006

The 1-allylpyrazole complexes of the general formula Fe(CO)3L (L=substituted 1-allylpyrazoles) have been prepared by the photochemical reaction of Fe(CO)5 in the presence of 1-allylpyrazoles, and characterized by the IR, 1H-, and 13C-NMR spectroscopies. These complexes show a large decrease of ν(C=C) frequency and 1H-and 13C-NMR upfield shifts of the olefinic nuclei compared with free ligands. The upfield shifts of olefinic 1H-NMR spectra are not influenced by the substituent groups on the pyrazole ring, but, so far as the terminal olefinic protons are concerned, the shifts are distinctively decreased on replacement of the allyl by the 2-methylallyl group. The upfield shifts of 13C-NMR spectra substantially parallel those of 1H-NMR spectra in these complexes. On refluxing Fe(CO)3L in a hexane solution containing PPh3, the complex liberates 1-allylpyrazole to give trans-Fe(CO)3(PPh3)2 in a small yield. Some new complexes of general formula M(CO)4L (M=Cr, Mo, or W, L=1-allylpyrazole) have also been prepared for comparison.
Stereoselective Substitution of trans-2-Butene for the S,S-2-Butene in Trichloro-S,S-2-buteneplatinate(II) in Acetone
Authors: Terai Yoshiro , Saito Kazuo
Published: July 2006

A new complex salt [Ph4P][PtCl3(S,S-tbn[1,3-3H])] (tbn, trans-2-butene) undergoes racemization and ligand isotopic exchange in acetone containing a large excess of tbn without side reactions. Both rates are expressed by the second order rate equations, R(CD)=K2(CD)[Pt][tbn] and R(IE)=K2(IE)[Pt][tbn], the k2 values being 17.6 and 70.6×10−3M−1s−1 at 8.0 °C, respectively (M=mol dm−3). Individual k2 values for the substitutions without and with inversion of configuration of coordinated tbn are calculated to be 62.0 and 8.7×10−3M−1s−1, respectively, the corresponding ΔH\eweq and ΔS\eweq values being 36.3±3.1 and 37.6±2.7 kJ mol−1, and −138±12 and −149±10 J· mol−1 Kr−1. Source of the stereoselectivity appears to consist in the difference in ease of formation of square pyramidal transition state on the nucleophilic attack of tbn upon the complex.
Non-isothermal Studies of the Dehydration of Double Salt Hydrates and Their Deuterium Oxide Analogues, I
Authors: Ray Chaudhuri N , Dasgupta M K , Mitra S , Pathak G K
Published: July 2006

Non-isothermal studies of the dehydration of double salt hydrates of the type (NH4)2AB4·M(II)SO4·6H2O and their D2O analogues in solid state were carried out with a derivatograph, where AB4=BeF42− or SeO42−, M(II)=Mg(II), Mn(II), Co(II), Ni(II), Cu(II), or Zn(II). These salt hydrate molecules lost water/heavy water in single or multiple steps upon heating. Intermediate hydrates were isolated and characterised by elemental analysis and IR spectral measurements. The activation energy for each step of dehydration of the salt hydrate was evaluated from the analysis of TG, DTG, and DTA curves of the respective derivatograms. Enthalpy change was evaluated from the DTA peak area and the order of reaction was found to be unity for each step of dehydration. The nature of dehydration was little affected by deuteration. Thermal parameters for the (NH4)2AB4·M(II)SO4·6H2O and their D2O analogues were compared with the salt hydrates, K2AB4·M(II)SO4·6H2O, (NH4)2SO4·M(II)SO4·6H2O and their D2O analogues.
Kinetics and Mechanism of Thermal Isomerisation of Aryl Alkanehydrazonates into N′,N′-Diarylhydrazides. Extension of a Recent Free Radical Analogue of the Chapman Rearrangement
Authors: Shawali Ahmad Sami , Hassaneen Hamdi Mahmoud , Almousawi Saleh
Published: July 2006

A series of twelve aryl N-(p-nitrophenyl)alkanehydrazonates (I) have been prepared and their thermal rearrangement into N-acyl-N′,N′-diarylhydrazines (II) was investigated. The structures of I and II were derived from their elemental analyses and spectral properties. Hydrolysis of II afforded the corresponding N′,N′-diarylhydrazines. Kinetic experiments have shown that electron withdrawing substituents decrease the rate of the rearrangement whereas electron donating groups increase it. The rate of conversion of I into II was also increased by addition of benzoyl peroxide. A free radical mechanism was proposed to account for the results.
Structural Assignment by NMR Spectroscopy: Restricted Rotation about Aryl C–N Bond and Configurations of Diels-Alder Adducts
Authors: Verma Shiva Mohan , Singh Nripendra B
Published: July 2006

Restricted rotation and non-planar conformations about the aryl C–N bond in ortho substituted arylimides have been studied in order to assign the endo and exo configurations of Diels-Alder adducts, employing the adducts of maleic anhydride with naphthalene and cyclopentadiene as model compounds. The adducts are readily transformed into their o-tolylimide derivatives and the N-o-tolyl probes satisfactorily into the magnetic environment of the cage moiety. In 1-naphthylimide derivatives, the naphthyl group causes splitting in the cage-proton resonances and is found to be more diagnostic for structural assignment.
Solvolysis in Carboxamides. II. Solvolytic Elimination of 7β-Methylbicyclo[3.3.1]non-3β-yl Tosylate in Carboxamides
Authors: Saito Seiki , Yabuki Tatsumi , Moriwake Toshio , Okamoto Kunio
Published: July 2006

Solvolysis of 7β-methylbicyclo[3.3.1]non-3β-yl tosylate (1) was carried out in a series of carboxamides, N-methylformamide (NMF), N-methylacetamide (NMA), N,N-dimethylformamide (DMF), and N,N-dimethyl-acetamide (DMA), as solvents. The rate (k1 first-order rate constant) of 1 decreases in the order NMF>NMA>DMF>DMA, a linear free-energy relationship being found between the rates of 1 and those of 1-adamantyl tosylate in acetic acid and 80% ethanol as well as the carboxamides. The products consist of olefin (≥96%) (exo-7-methylbicyclo[3.3.1]non-2-ene (4) and 3-methylbicyclo[3.3.1]non-2-ene (5)) and small amounts of esters (acetates or formates, ≤4%). The content of rearranged olefin 5 is considerably less than that of acetolysis (55%) and ethanolysis (55%), decreasing in the order NMF (34%)>NMA(22%)>DMF(13%)>DMA(9%). A linear reactivity-selectivity relationship holds between log k1 and log (%5/%4) for the four carboxamide solvents. The observed kinetic isotope effect (kH/kD=1.01±0.03) for 7α-deuterium-tagged derivative (1-7α-d) in NMF indicates that the σ(C(7)–H)-assisted ionization process for the solvolysis of 1 in the amides is absent. The results are in line with the stepwise mechanism which involves the formation of an intimate ion-pair intermediate followed by competitive processes such as 1,5-hydride shift, syn-El reaction, and nucleophilic substitution by the amide molecules. Substitution by the amide molecule leads to the formation of a cationic imidate, the hydrolysis of which affords the carboxylic esters. It is proposed that the syn-El process via an intimate ion-pair intermediate is affected by the tosylate anion reactivity in each amide solvent and suppressed by the hydrogen bonding of the each amide with the tosylate anion.
Chemistry of Nitrosoimines. XVI. A New Method for Facile Preparation of Azamonomethinecyanines via Nitrosoimines
Authors: Akiba Kin-ya , Ishikawa Kiyofumi , Inamoto Naoki
Published: July 2006

The reaction of 3-substituted 2-nitrosoimino-2,3-dihydrobenzothiazoles (1) with Grignard-type reagents of 3-substituted 2-imino-2,3-dihydrobenzothiazoles (2) gave azamonomethinecyanines (3) in high yields (71–96%). This is a new type of reaction for the preparation of 3. Hydrolysis of 3 afforded ring-opened disulfides, bis[o-{N-methyl-N-(3-methyl-2,3-dihydrobenzothiazol-2-ylidenecarbamoyl)amino}-phenyl] disulfides, in high yields (78–85%). Formation of by-products is explained by the presence of transnitrosation between 1 and 2 and ring-opening equilibrium of Grignard-type reagent of 2-imino-3-phenyl-2,3-dihydrobenzothiazole.
Ion-Molecule Reactions in the Binary Mixture of Ethylene Oxide and Trioxane. II. Mechanism for Reaction of Ethylene Oxide Molecular Ion with Trioxane
Authors: Kumakura Minoru , Arakawa Kazuo , Sugiura Toshio
Published: July 2006

The ion-molecule reactions in the binary mixture of ethylene oxide and trioxane have been studied with use of a modified time-of-flight mass spectrometer. As cross-reaction product ions, C3H5O2+, C3H6O2+, and C3H7O2+ were observed under the conditions of long delay times and elevated pressure. It was found that these ions are formed by the dissociation of unstable intermediate-complex resulting from the reaction of ethylene oxide molecular ion with trioxane. It was proposed that the complex is of cyclic structure in which positive charge is delocalized. From the consideration of isotopic distribution of the prodoct ions in ethylene-d4 oxide–trioxane mixtures, the skeletal structures of the product ions were investigated. The rate constants of the formation reactions of C3H5O2+, C3H6O2+, and C3H7O2+ in ethylene oxide–trioxane mixtures were found to be 2.20×10−10, 2.61×10−10, and 1.74×10−10 cm3 molecule−1 s−1 respectively.
Formation of 1,3-Di(2-fluorenyl)-1-butene from 2-(1-Bromoethyl)fluorene with Silver Powder
Authors: Minabe Masahiro , Suzuki Makoto , Ooya Takao , Suzuki Kazuo
Published: July 2006

An unexpected compound, 1,3-di(2-fluorenyl)-1-butene, was formed as the major product, accompanied by meso- and dl-2,3-di(2-fluorenyl) butane as the minor products, in the reaction of 2-(1-bromoethyl)fluorene with silver powder. The structure of the butene was confirmed to be the E form by a comparison of the UV spectra of the related compounds.
α,β-Unsaturated Carboxylic Acid Derivatives. XIII. The Synthesis and Configuration of Alkyl 2-Acylamino-2-alkenoates and Their Cyclized 2,5-Piperazinedione Derivatives
Authors: Shin Chung-gi , Hayakawa Masato , Suzuki Takamichi , Ohtsuka Akira , Yoshimura Juji
Published: July 2006

It is described that alkyl (E)- and (Z)-2-halo (Cl, Br, and I)-acetylamino-2-alkenoate (DHA), obtained by the condensation of alkyl 2-oxoalkanoate with chloro- or bromoacetamide and by halogen exchange from the chlorine of DHA to iodine, are cyclized with ammonia or hydroxylamine to give the (E)- and (Z)-isomers of unsymmetric 3-alkylidene-2,5-piperazinediones and their 1-hydroxy derivatives respectively. Alkyl (E)- and (Z)-2-iodoacetylamino-2-alkenoates were converted into the corresponding acetylamino- and phthalimidoacetylamino derivatives. The configurations of all the DHA and 2,5-piperazinedione derivatives were determined from the NMR spectra data.
Electrophilic Sulfides(II) as a Novel Catalyst. VI. Reaction of Sulfonium Ylides with Arenesulfenyl Thiocyanates
Authors: Matsuyama Haruo , Minato Hiroshi , Kobayashi Michio
Published: July 2006

Arenesulfenyl thiocyanates (Ar–S–SCN) reacted with sulfonium ylides (MeR\overset⊕S–\overset\ominusC(COOMe)2) in chloroform at room temperature, forming sulfonium ion, MeRS⊕–C(SAr)(COOMe)2 SCN\ominus, which further reacted. The mechanism of this reaction was discussed.
NvT- and NpT-ensemble Monte Carlo Simulations of Ionized Matter. I. NvT-ensemble Study on Calcium Oxide Near Normal Melting Point
Authors: Yamamoto Akio , Murata Hiromu
Published: July 2006

With special attention to calcium oxide, values obtained by NvT-ensemble Monte Carlo calculations are reported for the internal energy, pressure, heat capacity, thermal pressure coefficient, Grüneisen’s γ, and component radial distribution functions of ionized matter in the condensed phases. The calculations cover 14 vT points: seven points lying on one isochore at the X-ray density and eight on one isotherm at the normal melting point. Both thermodynamic quantities and structural properties in the vicinity of the melting point are indicative of the fluidsolid phase change. A brief comparison of the Monte Carlo results with the experimental data is also made.
Reclamation of Vulcanized Rubbers by Chemical Degradation. IX. Oxidative Degradation of cis-1,4-Polyisoprene by Phenylhydrazine-Iron(II) Chloride System
Authors: Kawabata Nariyoshi , Yamashita Shinzo , Furukawa Yoshinori
Published: July 2006

Degradation of cis-1,4-polyisoprene by phenylhydrazine-iron(II) chloride system was investigated in benzene solution at 30 °C in the air. Separate use of the two chemicals was much less effective for degradation. The number of chain scission was found to depend upon only the amount of phenylhydrazine, independent of that of iron(II) chloride, indicating that phenylhydrazine plays the leading part of the phenylhydrazine-iron(II) chloride system in the degradation. When iron(III) chloride was used instead of iron(II) chloride, the degradation became slower, but the number of chain scission was not significantly affected.
Potassium–Sodium Ion Exchange Isotherm of Crystalline Zirconium Arsenate
Authors: Sugisawa Junko , Yonezawa Takao , Takaguchi Kazunori , Tomita Isao
Published: July 2006

When the forward and reverse Na+–K+exchange isotherm was investigated for the α-zirconium arsenate ion exchanger, a large hysteresis loop was observed. The interlayer distance of the exchanger decreased with an increase in the ionic fraction of Na+ in the exchanger. The result may be interpreted in terms of the formation of different types of solid solutions during the processes in both directions.
The Preparation and the Structure of Cobalt(III) Complexes Containing a cis-2-Butene-1,4-diamine Chelate Ring
Authors: Soma Yoshikuni , Mizukami Fujio
Published: July 2006

New cobalt(III) complexes containing a seven-membered chelate ring, [Co(en)2(dcb)]3+, [Co(acac)2(dcb)]+ and [Co(dcbta)]−,were synthesized and resolved into optical isomers, and their structures were determined; dcb=cis-2-butene-1,4-diamine, dcbta=cis-2-butene-1,4-diamine-N,N.N′,N′-tetraacetate ion.
Binuclear Metal Complexes. XXI. Copper(I)–Copper(II) Mixed-Valence Complexes with Quadridentate Schiff Bases
Authors: Okawa Hisashi , Kasempimolporn Visit , Kida Sigeo
Published: July 2006

Copper(I)–copper(II) mixed-valence complexes of the quadridentate Schiff bases were obtained and characterized. ESR and visible spectra showed no evidence for the delocalization of an unpaired electron between copper(I) and copper(II) ions.
Isolation and Photolysis of 2,3-Bis(diphenylmethylene)-5,6-diazaspiro[3.4]octa-5,7-dien-1-ones
Authors: Ueda Kozaburo , Toda Fumio
Published: July 2006

Pyrazole given in the title was prepared by the reaction of 2-diazo-3,4-bis(diphenylmethylene)cyclobutanone with acetylenes. Photolysis of the pyrazole afforded 1,2-dihydro-3H-benzo[a]cyclobuta[c]cycloheptan-1-one.
Microwave Spectrum, Structure, and Quadrupole Coupling Constant of o-Chlorophenol
Authors: Onda Masao , Oshima Yoshitomo , Yamaguchi Ichiro
Published: July 2006

The microwave spectrum of o-chlorophenol has been observed in the frequency range 10–34 GHz. The rotational and centrifugal distortion constants were obtained for two isotopic species, 35ClC6H4OH and 37ClC6H4OH. The analysis of the hyperfine structure gives the following nuclear quadrupole coupling constants for 35Cl species: χaa=−67.6, χbb=33.3, and χcc=34.3 (MHz). The spectrum assigned has been attributed to the cis-form (intramolecularly hydrogen bonded between Cl and HO) from a brief consideration of the relative intensity of the a-and b- type transitions. No significant effect of the intramolecular hydrogen bonding on the nuclear quadrupole coupling was observed.
Lactones of Hydrogenated 5,8-Dihydroxy-4-methylnaphthalene-1-carboxylic Acids
Authors: Irikawa Hajime , Okumura Yasuaki
Published: July 2006

The γ- and δ-lactones were derived from the Diels-Alder adduct of p-benzoquinone and methyl sorbate.
Oxyhydrative Scission of trans-2-Butene in the Liquid Phase under Pressure
Authors: Takita Yusaku , Maehara Takashi , Yamazoe Noboru , Seiyama Tetsuro
Published: July 2006

The liquid phase oxidation of trans-2-hutene under pressure using a V2O5–MoO3 catalyst suspended in water has been proved to yield acetic acid and aldehyde selectively at 170 °C. Taking into account the results of the oxidation of intermediate compounds, it is suggested that the reaction follows the same oxyhydrative scission mechanism as has been proposed for the gas phase oxidation.
A Study of Ion-Solvent Interaction of Tetraalkylammonium and Common Alkali Metal Ions in Ethylene Carbonate from Electrolytic Conductance Data
Authors: Gopal Ram , Singh Sudha
Published: July 2006

Ion-solvent interaction in solutions of some tetraalkylammonium and common alkali metal iodides in ethylene carbonate, from the point of view, of electrical conductance and the derived Walden product, has been examined in this communication. The Debye-Hückel-Onsager equation appears to hold good for all the salts in the temperature and concentration range studied here. Dependence of the Walden product on temperature and radius of cation reveals that the R4N+ ions do not interact appreciably with the solvent but Li+, Na+, K+, and Rb+ ions appear to be solvated.
The Crystal Structure of the A-super Form of Laurie Acid
Authors: Goto Midori , Asada Eiichi
Published: July 2006

The crystal structure of the A-super form of lauric acid has been determined. The structural parameters were refined by the block-diagonal least-squares method, and the final R value was 0.094. Two types of molecular conformations of a lauric acid exist in the crystal; one is the ordinary type, as seen in the C-form or the A1-form of the lauric acid, while the other is that rotating the carboxyl group about the C1–C2 bond. This unusual structure was explained by the oxygen-oxygen distance of the adjacent molecule.
The Formation of Nitrogeneous Compounds in the γ-Radiolyses of Liquid Nitrogen Solutions of Hydrogen, Methane, and Ethane
Authors: Horigome Keiichi , Hirokami Shun-ichi , Sato Shin
Published: July 2006

The γ-radiolyses of liquid nitrogen solutions of hydrogen, methane, and ethane have been reinvestigated. A complete survey of nitrogen-containing products has been attempted. The nitrogeneous compounds observed were ammonia (0.7) and hydrogen azide (0.02) in the case of hydrogen, ammonia (0.3), hydrogen cyanide (0.1), methyl azide (0.01), and a polymer in the case of methane, and ammonia (0.3), hydrogen cyanide (0.05), acetonitrile (0.04), ethyl azide (0.01), and a polymer in the case of ethane. The values in parentheses are the G-values obtained at optimum conditions. The hydrolysis of the polymer obtained with methane gave formaldehyde in amounts which correspond to the fact that the G-value of the nitrogen atoms which were converted into the polymer is about 1.0. In order to explain these results, possible reaction mechanisms are discussed.
Measurements of the Solubility Coefficients of Gases and Vapors in Natural Rubber by Gas Chromatographic Technique
Authors: Kawakami Mitsuyasu , Kagawa Shuichi
Published: July 2006

The solubility coefficients of hydrocarbons in unvulcanized natural rubber at 25 °C were determined by gas-liquid chromatography. Natural rubber was used as a stationary liquid and nine kinds of lower olefins and paraffins as solutes. The retention volume for all the solutes did not vary with sample size. It was found that the correction for gas phase imperfection is negligible. Thus the solubility coefficient was readily obtained from the specific retention volume without any correction. The values obtained were in fairly good agreement with those determined by the volumetric method given in other works. Modified equations expressing the relationships between the solubility coefficient and the boiling temperature, the critical temperature, and the Lenard-Jones force constant, which might be applicable to a more extensive range of gaseous compounds, were presented.
The Electronic Structure of Ru(III)–Ammine Complexes and the Product Distribution from Solid-state Thermal Reaction
Authors: Kohata Susumu , Sakaki Shigeyoshi , Ohyoshi Akira
Published: July 2006

INDO-type UHF-MO calculations were carried out for Ru(III)-ammine complexes in order to investigate their electronic structures and bonding nature. It was revealed that the ground state of RuX(NH3)52+(X=F, Cl, Br, or I) is the 2E state and that that of cis-RuX2(NH3)4+ is the 2A1 state; in RuX(NH3)52+, the odd electron exists not on the dxy orbital but on the dxz or dyz orbital which interacts with the pπ orbital of the halide ligand, and in cis-RuX2(NH3)4+, this electron exists not on the dxz or dxy orbital but on the dyz orbital which interacts with the pπ orbitals of the two halide ligands. Concenring the bonding nature, the following results were obtained: (1) the strength of the Ru–NH3 bond in these complexes increases in the order, cis-RuX2(NH3)4+<RuX(NH3)52+<Ru(OH2)(NH3)53+<Ru(NH3)63+; (2) in the aqua-ammine complex, the Ru–OH2 bond is weaker than the Ru–NH3 bond; and (3) in the halogeno-ammine complexes, the trans-Ru–NH3 bond is weaker than the cis-Ru–NH3 bond. MO calculations were also carried out for some distorted states of RuCl(NH3)52+ From these results, a discussion is presented on the relation between the thermal reaction product and the reaction mechanism; cis-RuCl2(NH3)4+ is expected to be produced via an associative reaction mechanism, while the trans-form product is expected to result from a dissociative mechanism.
X-Ray Fluorescence Spectroscopy of Binary Silicate Glasses
Authors: Maekawa Takashi , Kikuchi Niro , Sumita Shigekazu , Yokokawa Toshio
Published: July 2006

The Si Kα emission lines of the several silicon compounds and binary silicate (Na, K, Rb, and B-silicates) glasses were measured. In the binary silicates, negative energy shifts from that of SiO2 were observed. They were interpreted as indicating a relative decrease of the quantity of charge transfer from silicon to oxygen, when more electropositive elements like alkali metals are located on the next nearest neighbor positions of the silicon atoms. The Si Kα shifts of silicate glasses have a good correlation with the basicity of their melts.
Emission Spectra of the Vinyl Polymers with Pendant Benzocarbazolyl Groups
Authors: Itaya Akira , Okamoto Ken-ichi , Kusabayashi Shigekazu
Published: July 2006

The emission spectra of poly(N-vinyl-5H-benzo[b]carbazole) (PV5BCz) and poly(N-vinyl-7H-benzo[c]carbazole) (PV7BCz), which are prepared by radical and cationic polymerization, and their monomeric model compounds were investigated in solutions. In the case of PV7BCz, the fluorescence spectra were composed of a second excimer fluorescence at the shorter wavelength and a sandwich-like excimer fluorescence at the longer wavelength. The difference in the spectra between the radical and cationic polymers was quite similar to that of the poly(N-vinylcarbazole) (PVCz) system. The intensity of the sandwich-like excimer fluorescence was independent of the polymerization methods, but the intensity of the second excimer fluorescence increased with an increase in the content of the syndiotactic sequence. In the case of PV5BCz, the behavior of the fluorescence spectra of the radical polymers was similar to that of the PVCz and PV7BCz systems. On the other hand, the fluorescence spectra of the cationic polymers differed markedly from those of the above-mentioned polymers. The cationic polymers did not show the second excimer fluorescence, but a monomer-like structured fluorescence, at the shorter wavelength, although it did show the sandwich-like excimer fluorescence at the longer wavelength. This significant difference in the fluorescence spectra between the radical and cationic polymers is attributable to the difference between their tacticities. On the basis of these results, the characteristics of the second excimer site were further clarified.
Ligand Effects of 2,2′-Bipyridine in the Decomposition of 1,2,3,4-Tetrahydro-1-naphthyl Hydroperoxide Catalyzed by Cobalt(II) Salt
Authors: Yamada Teruaki , Kamiya Yoshio
Published: July 2006

The ligand effect of 2,2′-bipyridine on the rate of the decomposition of 1,2,3,4-tetrahydro-1-naphthyl hydroperoxide catalyzed by cobalt(II) decanoate in chlorobenzene was kinetically studied and compared with the redox potentials and the spectral data of cobalt(II) complexes. The activity of the anhydrous cobalt(II) decanoate increased by a factor of from three to seven by the addition of 2,2′-bipyridine when the molar ratio of 2,2′-bipyridine to cobalt was 0.25 to 2. It was found that the catalytic activity of the anhydrous cobalt(II) decanoate-2,2′-bipyridine complex shows a remarkable maximum value at the molar ratio of 2,2′-bipyridine to cobalt of 0.5. This novel finding can be explained on the basis of the redox potential measured by cyclic voltammetry in dichloromethane, the IR data, and the structure of the catalyst. The coordination of 2,2′-bipyridine causes the redox potential to change from 0.80–0.84 V to 0.60–0.64 V (vs. SCE) and also weakens the Co–O(decanoate) bond strength, resulting in a facile coordination of hydroperoxide to the cobalt ion as well as the acceleration of cleavage of hydro-peroxide. The maximum activity was explained by the proposed structure of the cobalt(II) decanoate-2,2′-bipyridine (1 : 1/2) complex with a fairly low redox potential and a vacant coordination site.
The Photo-cycloaddition of 3-Cyano-2,4-pentanedione with Cyclohexene and Its Quenching by Enol Ether
Authors: Tada Masaru , Harada Hidetoshi , Miura Kyo
Published: July 2006

The 1,3-dicarbonyl compound, with an electro-negative substituent, 3-cyano-2,4-pentanedione, gives the photoaddition product with cyclohexane. The adduct must be formed by the retro-aldol reaction of the “2+2” cycloaddition product and the hemiacetalization of the resulting 1,5-dicarbonyl compound. Enol ether, with a lower ionization potential, does not photoadd to 3-cyano-2,4-pentanedione but quenches the photoaddition between 3-cyano-2,4-pentanedione and cyclohexene. The solvent effect, the ionization potential, and quenching experiments show that the photoaddition follows a process involving a singlet excited complex.
Nucleoside Analogs. 6. A Synthesis of Carbocyclic Puromycin Analogs
Authors: Suami Tetsuo , Tadano Kin-ichi , Ayabe Mitsukuni , Emori Yasufumi
Published: July 2006

Eight carbocyclic puromycin analogs, in which the furanosyl ring of puromycin is replaced with a cyclopentyl system, were synthesized. Their minimum degeneration concentration (MDC) was determined against HeLa cells in a tissue culture. The two analogs were found to be remarkably active.
Studies of Unusual Amino Acids and Their Peptides. IX. The Synthetic Study of Bottromycins B1 and B2
Authors: Yamada Takashi , Takashima Katsumi , Miyazawa Toshifumi , Kuwata Shigeru , Watanabe Hiroshi
Published: July 2006

Bottromycins B1 and B2, peptide antibiotics, were synthesized according to the structures proposed by Nakamura et al. B1 was obtained by the condensation of the imidate, Piv–Tle–Val–ImPro–OEt·HCl with the ester, H–Gly–Phe(βMe)–β-Tha–OH in the presence of Et3N, and B2 by the replacement of the Z group of Z–Tle–Val–ImPro–Gly–Phe(βMe)–β-Tha–OMe by the trans-4-methyl-2-pentenoyl group. The structures of the synthetic B1 and B2 were confirmed by elemental analyses, amino acid analyses, and Cl-mass spectra. However, the synthetic bottromycins differed from the natural ones in many respects, e.g., IR spectra, behavior in TLC, and pKa values. Most significantly, no antimicrobial activities were detected in the synthetic B1. On the basis of these results, it is concluded that the structures proposed by Nakamura et al. for bottromycins are erroneous and should be revised.
13αH-Olean-18-ene Derivatives. Forced Wolff-Kishner Reduction Products of 19-Oxoolean-12-ene Derivatives
Authors: Honda Tadashi , Murae Tatsushi , Tsuyuki Takahiko , Takahashi Takeyoshi
Published: July 2006

Methyl 2α,3β,23-triacetoxy-13αH-olean-18-en-28-oate (4) and methyl 2α,3β-diacetoxy-13αH-olean-18-en-28-oate (7) were obtained from methyl 2α,3β,23-triacetoxy-19-oxoolean-12-en-28-oate (2) and from methyl 2α,3β-diacetoxy-19-oxoolean-12-en-28-oate (5), respectively, by the forced Wolff-Kishner reduction and subsequent acetylation and methylation. Methyl 2α,3β-diacetoxy-13βH-olean-18-en-28-oate (10), prepared from methyl 2,3-di-O-acetylarjunate (13) via methyl 2α,3β-diacetoxy-19α-hydroxy-12-oxooleanan-28-oate (18) and methyl 2α,3β-diacetoxy-19α-hydroxyoleanan-28-oate (19), was shown to be not identical with 7. This led to a 13αH-olean-18-ene structure for 7.
Formation of Bis(methylthio)(methylsulfinyl)methane in the Reaction of Methyl (Methylthio)methyl Sulfoxide with Sodium Hydride
Authors: Ogura Katsuyuki , Katoh Nobuko , Tsuchihashi Gen-ichi
Published: July 2006

Treatment of methyl (methylthio)methyl sulfoxide (1) with sodium hydride gave bis(methylthio)(methylsulfinyl)methane (3) which might be formed by abnormal attack of the carbanion (2) of 1 on the sulfide linkage of 1. The additon of butyl iodide to this system completely suppressed the formation of 3, showing that 2 reacts faster with butyl iodide than with 1. The mechanism to account for these phenomena is discussed.
Substrate-Nucleophile Association in the Finkelstein Reaction System in Dipolar Aprotic Solvent. Formation of Complex between Substituted Chloromethanes and Halide Ion in Acetonitrile
Authors: Hayami Jun-ichi , Koyanagi Tohru , Hihara Nobuhisa , Kaji Aritsune
Published: July 2006

Substrate-nucleophile association was found between substituted chloromethanes (ArXCH2Cl: X=NONE, S, SO, SO2, and CO) and halide ion (Cl−, Br−, and I−) in dipolar aprotic solvent. The equilibrium constant (K), limiting shift (Δc), the enthalpy of formation (ΔH°), and the entropy of formation (ΔS°), for complexing were determined by NMR measurement. The measurement of spin-lattice relaxation time (T1) gave an information on the conformation of this complex. Halide ion seems to locate closest to α-methylene protons at the site of potential SN2 reaction.
Abnormal Wallach Rearrangement of 4-Alkylazoxybenzenes
Authors: Shimao Ichiro , Matsumura Shigenori
Published: July 2006

The major product in the reaction of 4-alkylazoxybenzenes with sulfuric acid is not 4-(p-alkylphenylazo)phenol, which is regarded as the usual product of Wallach rearrangement. The following azophenols were obtained as major products; 2-alkyl-5-(phenylazo)phenol (R : Me), 2-alkyl-4-(phenylazo)phenol (R : Et), and 4-(phenylazo)phenol (R : i-Pr and t-Bu).
A Synthesis of 2-Substituted 2-Cyclopenten-1-ones
Authors: Ide Junya , Sakai Kiyoshi , Yura Yasuo
Published: July 2006

2-Substituted 2-cyclopenten-1-ones, i.e., 2-(6-methoxycarbonylhexyl)-2-cyclopentene-1-on and 2-butyl-2-cyclopenten-1-one were synthesized by cyclization of the corresponding 4-oxo-1-pentanals, which were obtained from 3-substituted 1,1-dimethoxy-2,4-pentadiones through several steps.
MO Calculations of the Rydberg Transitions of the Methane Molecule
Authors: Kohda-Sudoh Susumu , Katagiri Shigeyoshi
Published: July 2006

The vertical transition energies of both the Rydberg and valence-shell type transitions of CH4 were calculated by the use of the ab initio SC-LCAO-MO method. We used Slater-type AO’s as the basis AO’s and added the extra-valence AO’s (3s, 3p, 4s, and 4p) of a carbon atom to the minimal-basis set in order to express the Rydberg MO’s. From the limited CI calculations, the mixing expressed in terms of the orthogonalized AO’s between the Rydberg and valence-shell transitions was shown to be little. The lowest two absorption bands near 9.7 and 11.7 eV were identified as a 3s-like Rydberg transition with a 3p-like one and a 4s-like Rydberg transition with a 4p-like one respectively. The total energy and Mulliken population analysis were also calculated and compared with the results of the minimal-basis calculations.
Reaction of Hydrogen Atoms with Acrylaldehyde
Authors: Koda Seiichiro , Nakamura Kazumoto , Hoshino Takashi , Hikita Tsutomu
Published: July 2006

The reaction of hydrogen atoms with acrylaldehyde was investigated in a fast flow reactor equipped with a time-of-flight type mass spectrometer under reduced pressure. Main reaction products were carbon monoxide, ethylene, ethane, methane, and propanal. Consideration of the distributions of the reaction products under various reaction conditions showed that hydrogen atoms attacked the C=C double bond, especially its inner carbon side under reduced pressure. Resulting hot radicals caused subsequent reactions. The relative value of the apparent bimolecular rate constant of the reaction against that of trans-2-butene with hydrogen atoms was 1.6±0.2, which supported the above-mentioned initial reaction.
Polarized Electronic Absorption Spectra and Assignment of Fluorene and Biphenyls
Authors: Yoshinaga Tetsutaro , Hiratsuka Hiroshi , Tanizaki Yoshie
Published: July 2006

The divided electronic spectra polarized parallel to the long and short axes of molecules of biphenyl, THP (4,5,9,10-tetrahydropyrene), fluorene, and DHPH (9,10-dihydrophenanthrene) were determined by dichroism analysis using the stretched PVA film method. The experimental results are in good agreement with the ones calculated by the LCAO MO SCF CI method. Every compound has a very weak absorption (f≈10−4) as the first band in the region of 32000–35000 cm−1, which is electronically allowed and polarized parallel to the short axis. The intense band (34000–44000 cm−1) of biphenyl consists of a relatively strong (39100 cm−1) band and a weak (40500 cm−1) band: the former is polarized parallel to the long axis and the latter to the short. Both fluorene and DHPH show five well corresponding electronic bands in the region below 45000 cm−1.
A Molecular Orbital Study on the Partial Reactivity of Hydrogen of Various Amino Acids in the Abstraction Reaction by Hydroxyl Radical
Authors: Shinohara Hiroyuki , Imamura Akira , Masuda Takahiro , Kondo Masaharu
Published: July 2006

The reactivities of hydrogen atoms of aliphatic amino acids toward hydroxyl radicals in the hydrogen atom abstraction reaction have been studied in terms of the energy required for stretching the C–H bond which is attacked. The energy required for stretching the C–H bond by 0.5 Å from the equilibrium bond length has been calculated by the INDO method and compared with the partial rate constants experimentally assigned to the hydrogen atoms of aliphatic amino acids. The energy required has been correlated only with the partial rate constants of the hydrogen atoms on the β-carbon atom. For the hydrogen atoms on the α-carbon atom, although data was insufficient a similar situation has been observed. The reactivities of the hydrogen atoms on the γ and δ-carbon atom failed to correlate with the stretching energy. The reasons are discussed in terms of the effect raised by the configuration of amino acid molecules in solution. The stretching energy has also been found to be consistent with the electrophilicity observed in the hydrogen abstraction reaction by hydroxyl radical.