bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reaction of Organic Tin(II) Compound with Phenyl Isothiocyanate and Carbon Disulfide
Authors: Wakeshima Ikuko , Saitoh Yoshihiro , Kijima Ichiro 
Published: July 2006

Abstract
Reaction of organic tin(II) compounds, Sn(OR)2[R=C2H5, CH2CH2N(CH3)2, C6H5, o-CH3C6H4], with phenyl isothiocyanate and carbon disulfide have been investigated. The reaction of di(ethoxo)tin(II) with phenyl isothiocyanate in benzene at room temperature gave the corresponding addition product. The reaction at 80–81 °C however gave diethyl N-phenylcarbonimidate. Phenyl isothiocyanate reacted exothermically with bis[2-(dimethylamino)ethoxo]tin(II) to yield the 1 : 1 addition product. In the reaction with bis(2-methylphenoxo)tin(II), a compound containing one molecule of phenyl isothiocyanate per two molecules of the tin(II) compound was isolated, but the reaction with di(phenoxo)tin(II) did not occur. Di(ethoxo)tin(II) reacted with carbon disulfide to give diethyl thiocarbonate, diethyl carbonate, and tetraethyl orthocarbonate. Bis(o-methylphenoxo)tin(II) and di(phenoxo)tin(II) however did not react with carbon disulfide.
The Chlorination of Norbornene and Cyclooctadienes with Sulfuryl Chloride and Phosphorus(V) Chloride. Ionic vs. Radical Chlorination with Each Reagent
Authors: Uemura Sakae , Okazaki Hajime , Onoe Akira , Okano Masaya 
Published: July 2006

Abstract
The chlorination of norbornene and cyclooctadienes with sulfuryl chloride and phosphorus(V) chloride has been investigated mainly in carbon tetrachloride under various conditions. From the studies of the product distributions and the effect of radical scavengers, the following facts have been revealed for the first time in olefin chlorination: chlorination with sulfuryl chloride proceeds through an ionic pathway at room temperature or in the presence of silica gel and that with phosphorus(V) chloride through a radical pathway at elevated temperature, and an ionic chlorination with phosphorus(V) chloride in nonpolar solvents does not seem to involve C–P bond formation through the reaction.
Synthesis of (±)-Tetrahydroanhydroaucubigenone and (±)-Tetrahydroanhydroaucubigenin
Authors: Obara Heitaro , Kimura Hiroshi , Suzuki Masanobu , Onodera Jun-ichi 
Published: July 2006

Abstract
The racemate of tetrahydroanhydroaucubigenone (3), one of the related compounds of aucubin, was synthesized by the photoirradiation of 6-[2-(nitrosooxy)ethyl]-3-oxabicyclo[3.3.0]octan-7-one. (±)-Tctrahydroanhydroaucubigenin was also obtained by reduction of (±)-3 with sodium in moist ether.
Synthesis of 2′,3′,4,4′,6′-Pentahydroxychalcone, an Aglycone of Carthamin, and Its Isomerization into 4′,5,6,7- and 4′,5,7,8-Tetrahydroxyflavanone, Carthamidin and Isocarthamidin
Authors: Obara Heitaro , Onodera Jun-ichi , Kurihara Yuji , Yamamoto Fumitada 
Published: July 2006

Abstract
2′,3′,4,4′,6′-Pentahydroxychalcone (4), an aglycone of carthamin, was synthesized by the demethoxymethylation of 2′,3′,4,4′,6′-pentakis(methoxymethoxy)chalcone prepared by the condensation of 2,3,4,6-tetrakis(methoxymethoxy)acetophenone with p-methoxymethoxybenzaldehyde. 4 was converted into 4′,5,6,7- and 4′,5,7,8-tetrahydroxyflavanone (5 and 6) by boiling with methanolic hydrochloric acid. On the basis of the comparisons of the properties of 5 and 6 with those of carthamidin (A) and isocarthamidin (B) derived from natural product, the structures originally assigned for A and B should be reversed.
Optical Spectra of the Picrate Ion in Micellar and Polymer Micellar Systems. Comment on the Solvation of Anions
Authors: Shinkai Seiji , Ide Toyoko , Manabe Osamu 
Published: July 2006

Abstract
The optical spectra of the picrate ion in a micellar solution indicate that slightly below the CMC of CTAB surfactant the anion is relatively free and exists as an ion pair above the CMC. The hydrophobic aggregate of TMAC invariably gives free ion. The polymer micelle of quaternized poly(4-vinylpyridine) results in a tight ion pair.
Optical and Magnetic Properties of Crystalline Phenothiazine Cation Radical Salts
Authors: Iida Yôichi 
Published: July 2006

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.