bluuebunny/crossref_metadata_2025 huggingface dataset:
Predominant Intramolecular Pummerer Reactions of Substituted Benzyl p-Tolyl Sulfoxides with Acetic Anhydride
Authors: Itoh Osamu , Numata Tatsuo , Yoshimura Toshiaki , Oae Shigeru
Published: July 2006

In the Pummerer reactions of 18O-labeled benzyl, and 3,5-dichlorobenzyl p-tolyl sulfoxides with a large excess of unlabeled acetic anhydride in the presence of DCC as acid scavenger, the resulted Pummerer reaction products, the α-acetoxy sulfides, were found to have retained substantial amounts of 18O-label of the original sulfoxides, i.e., nearly a half or more. Meanwhile, when optically active benzyl, 3-chlorobenzyl, and 3,5-dichlorobenzyl p-tolyl sulfoxides were allowed to react with excess acetic anhydride in the presence of DCC, the α-acetoxy sulfides, the Pummerer reaction products obtained, were found to have no optical activity. These observations suggest that the acetoxyl migration from sulfur atom to α-carbon is predominantly intramolecular, however, the α-(p-tolylthio) carbenium acetate ion-pair formed during the reaction prior to racemization is less intimate than those which are formed in the reactions of cyanomethyl and (α-carbonyl-substituted methyl) p-tolyl sulfoxides which give the corresponding highly optically active α-acetoxy sulfides.
The Baeyer-Villiger Oxidation of 8-Oxabicyclo[3.2.1]octan-3-ones. Substituent Effects on the Regioselectivity
Authors: Noyori Ryoji , Sato Tsuneo , Kobayashi Hiroshi
Published: July 2006

8-Oxabicyclo[3.2.1]octan-3-one derivatives serve as excellent models that elucidate factors controlling the reactivities and selectivities in the Baeyer-Villiger oxidation. The regioselectivity of the oxidation with trifluoroperacetic acid is markedly affected by the electronic properties of substituents at position α or β to the carbonyl function. Remote effects of the γ-substituents are also of significance. This study has disclosed yet unrecognized through-bond electronic influence and regioselection based on chiral orientation of hydroxyl group in the transient tetrahedral intermediate.
Stereocontrolled General Synthesis of Pyrimidine C-Nucleosides Having Branched-chain Sugar Moieties
Authors: Sato Tsuneo , Watanabe Makoto , Kobayashi Hiroshi , Noyori Ryoji
Published: July 2006

A variety of pyrimidine C-nucleosides bearing branched-chain sugars can be synthesized starting from adequately substituted (1R*,6S*,7S*,8R*)-7,8-isopropylidenedioxy-3,9-dioxabicyclo[4.2.1]nonan-4-ones. The general procedure consists of condensation with t-butoxybis(dimethylamino) methane, giving the corresponding α-dimethylaminomethylene lactones, base-catalyzed heterocycle formation with urea, thiourea, or guanidine, and acid-promoted removal of the isopropylidene protective group. The overall transformation proceeds with retention of the stereochemistry to afford only C-β-glycosyl nucleoside structures.
General Synthesis of Homo-C-nucleosides
Authors: Sato Tsuneo , Noyori Ryoji
Published: July 2006

Lithium aluminium hydride reduction of methyl (2,3-O-isopropylidene-5-O-trityl-β-d-ribofuranosyl) acetate gives 2-(2,3-O-isopropylidene-5-O-trityl-β-d-ribofuranosyl)ethanol. Subsequent tosylation, displacement by cyanide ion, nitrile hydrolysis, and diazomethane methylation afford methyl 3-(2,3-O-isopropylidene-5-O-trityl-β-d-ribofuranosyl)propionate. The base-promoted formylation followed by methylation with methyl iodide forms methyl 2-[(2,3-O-isopropylidene-5-O-trityl-β-d-ribofuranosyl)methyl]-3-methoxyacrylate. Base-catalyzed condensation of the methoxyacrylate and urea followed by deprotection produces 5-[(β-d-ribofuranosyl)methyl]uracil. In a like manner, condensation of the methoxyacrylate with thiourea or guanidine gives, after deblocking, 5-[(β-d-ribofuranosyl)methyl]-2-thiouracil and 5-[(β-d-ribofuranosyl)methyl]isocytosine, respectively. Ozonolysis of the methoxyacrylate yields methyl 3-(2,3-O-isopropylidene-5-O-trityl-β-d-ribofuranosyl)pyruvate, which undergoes condensation with carbamoylmethylenetriphenylphosphorane to furnish a mixture of methyl 2-[(2,3-O-isopropylidene-5-O-trityl-β-d-ribofuranosyl)methyl]fumaramate and 2-[(2,3-O-isopropylidene-5-O-trityl-β-d-ribofuranosyl)methyl]maleimide. Deprotection of the latter leads to 2-[(β-d-ribofuranosyl)methyl]maleimide. Condensation of the keto ester with ethyl hydrazinoacetate followed by cyclization affords 3-[(2,3,O-isopropylidene-5-O-trityl-β-d-ribofuranosyl)methyl]-5-methoxycarbonyl-4-hydroxypyrazole. Ammonolysis of the methyl ester and deprotection furnishes 3-[(β-d-ribofuranosyl) methyl]-5-carbamoyl-4-hydroxypyrazole.
Electron Microscope Studies on Radiography. III. Formation of Lumpish Developed Silver in Radiography
Authors: Hara Hiroshi
Published: July 2006

The shape of developed silver in industrial X-ray films exposed to a high energy radiation has been found mainly lumpish, which differs from the filamentary shape observed in ordinarily-developed photographic films. The formation process and crystalline states of lumpish silver were studied with an electron microscope in comparison with those of filamentary silver. Lumpish silver cannot be in a single uniform crystalline state under a kind of hindrance due to too active a development for regular crystal growth, the thickness of emulsion layer and the concentration of silver halide also have some effects.
Static and Kinetic Studies of the Interaction of Tryptophan with Fluorescein Mercury(II) Acetate by Fluorescence and Absorption Spectrophotometry and by Fluorescence Stopped-fiow Method
Authors: Ohnishi Masatake , Taniguchi Michio , Hiromi Keitaro
Published: July 2006

Fluorescein mercury(II) acetate (FMA) was found to combine with tryptophan (Trp) to form the FMA–Trp complex. The interaction was interpreted in terms of a reversible single-step binding mechanism. The dissociation constant of the complex estimated kinetically by means of the stopped-flow method using the forward and backward rate constants was in good agreement with that obtained by the static method. From comparison with several derivatives of tryptophan, it was found that the protonated amino group and the indole moiety of tryptophan are essential for the complex formation.
Spectrophotometric Determination of Iron(II) after Extraction of Its 4′-(p-Methoxyphenyl)-2,2′: 6′,2″-terpyridine Complex with Tetraphenylborate Anion into Molten Naphthalene
Authors: Lin Jenn-Lin , Chang Lih-Fen , Satake Masatada
Published: July 2006

A new method is described for the extraction of ion-associated complex of iron(II) 4′-(p-methoxyphenyl)-2,2′ : 6′,2″-terpyridine (abbreviated as MPTP) cation with tetraphenylborate (TPB) anion into molten naphthalene. The solid mixture containing the colored complex is dissolved in N,N-dimethylformamide (DMF) and the absorbance was measured at 576 nm. The other factors such as pH, amounts of reagents and naphthalene, shaking time and diverse ions are studied. The method has been applied for the determination of iron in reference materials and practical samples and the results was compared with the conventional 2,4,6-tri(2-pyridyl)-1,3,5-triazine (TPTZ) procedure.
Structural Study of Optical Resolution. XII. The Crystal and Molecular Structure of (−)589-trans-SS-Bis(isothiocyanato)(triethylenetetramine)cobalt(III) μ-(+)-Tartrato(4−)-μ-(+)-hydrogentartrato(3−)diantimonate(III) Tetrahydrate
Authors: Kushi Yoshihiko , Kuramoto Masahiro , Utsuno Shunji , Yoneda Hayami
Published: July 2006

The crystal and molecular structure of the diastereoisomeric salt, (−)589-trans-[Co(NCS)2(trien)][Sb2((+)-tart)((+)-tartH)]·4H2O, has been determined by the X-ray diffraction method. The red crystals were monoclinic, with the space group P21, a=8.987(1), b=15.949(2), c=10.726(1) Å, β=102.57(2)°, and Z=2. The structure was solved by the heavy-atom method and refined by the block-diagonal least-squares method, using 2976 independent reflections, to the final R-value of 0.033. In the complex cation, the conformations of the three five-membered chelate rings are (δλδ), while the absolute configurations of the two asymmetric nitrogen atoms are both S. The mononegative anion has a dimeric structure of [Sb2((+)-C4H2O6)((+)-C4H3O6)]−, in which (+)-C4H2O64− and (+)-C4H3O63− coordinate to two SbIII atoms. The extra hydrogen atom in (+)-C4H3O63− bonds to the free oxygen atom(OTB5) of the carboxylato group, and a short contact is formed between this oxygen atom and a water molecule(OW2); OTB5···OW2 2.43(1) Å. Though six N–H hydrogen atoms are present in the complex cation, three of them form N–H···O hydrogen bonds to the oxygen atoms of the dimeric anion; NTR3···OTA1 2.86(1), NTR4···OTA6 2.86(1), and NTR1···OTB4 3.19(1) Å.
Thiolate-bridged Metal Complexes. Nickel(II), Palladium(II), and Cobalt(III) Binuclear Complexes of 1,5-Diamino-3-pentanethiol
Authors: Murase Ichiro , Ueno Shigehiro , Kida Sigeo
Published: July 2006

A binucleating ligand with thiolate sulfur as a bridging atom, 1,5-diamino-3-pentanethiol (Hdpet) and its metal complexes, Ni2(dpet)2X2 (X=Br, ClO4, NO3, BPh4, and NCS) were synthesized. All the complexes are diamagnetic at room temperature. The Ni(II) and Pd(II) complexes assume binuclear thiolate-bridged square planar coordination. This structure is maintained even in aqueous solution. The electronic spectra of the Ni(II) complexes showed a band at 27.3×103 cm−1 corresponding to the 29.8×103 cm−1 band of [Ni2(dpl)2]2+ which is characteristic of oxo-bridged Cu(II) and Ni(II) complexes and was assigned to the pπ(O)→dσ(metal) transition. Several trials by different methods only resulted in the separation of a single species of Co(III) complex, Co2(dpet)3(ClO4)3. This was characterized as a bioctahedron facially joined at the three thiolate sulfur atoms.
Aromatic Nucleophilic Substitution. XVIII. Kinetics of Reactions of 2-(Acetylamino)ethyl 2,6-Dinitrophenyl Ether and N-Acetyl-N-(2-hydroxyethyl)-2,6-dinitroaniline with Sodium Isopropoxide
Authors: Sekiguchi Shizen , Hirai Motohiko , Tomoto Noboru
Published: July 2006

The kinetics of the reactions of 2-(acetylamino)ethyl 2,6-dinitrophenyl ether (Smiles rearrangement) and N-acetyl-N-(2-hydroxyethyl)-2,6-dinitroaniline with sodium isopropoxide in the DMSO–2-propanol mixture (20 : 80 v/v) was studied. Both reactions were found to rapidly produce the same spiro anionic σ complex, giving N-(2-acetoxyethyl)-2,6-dinitroaniline. Although the rates for formation of the complex were different in both reactions, the rates for rearrangement were the same.
Benzofuran Derivatives. I. On the Effects of Substituents in Benzofuran Syntheses
Authors: Suzuki Tsuneo , Horaguchi Takaaki , Shimizu Takahachi , Abe Teishiro
Published: July 2006

The Rössing’s reaction of 4-substituted 2-acylphenoxyacetic acids give a mixture of benzofurans and 2-benzofurancarboxylic acids. The relative yields of benzofurans and 2-benzofurancarboxylic acids depend on the substituents on the benzene ring of the 2-acylphenoxyacetic acids. Electron-withdrawing substituents such as nitro groups favor the formation of 2-benzofurancarboxylic acids. On the other hand, the formation of benzofurans is favored by the steric hindrance of 2-acyl groups in the reaction of 2-acyl-4-nitrophenoxyacetic acids with anhydrous sodium acetate and acetic anhydride.
Electro-organic Reactions on Organic Electrodes. Part 2. Electrochemical Asymmetric Reduction of Citraconic and Mesaconic Acids on Optically-active Poly(amino acid)-coated Electrodes
Authors: Nonaka Tsutomu , Abe Shigemitsu , Fuchigami Toshio
Published: July 2006

Influence of a number of electrolytic conditions on the asymmetric yield of methylsuccinic acid (2) formed in the electrochemical reduction of citraconic acid (1) on poly(amino acid)-coated electrodes was examined. The asymmetric yield was greatly affected by the conditions, while the absolute configuration of an excess enantiomer((S)-(−)-2) remained unchanged even when a polymer with the reversed configuration of the monomer unit was used. The configuration of the excess enantiomer was also unchanged in the asymetric reduction of mesaconic acid which is the geometrical isomer of 1.
Preparation, Characterization and Stereochemistry of 2-Methyl-2-silabicyclo[2.2.1]heptane Derivatives
Authors: Hosomi Akira , Mikami Masashi , Sakurai Hideki
Published: July 2006

A new class of bicyclic compounds containing a single silicon atom at the bridge, 2-exo- and endo-substituted 2-methyl-2-silabicyclo[2.2.1]heptanes, have been prepared from the corresponding 3-cyclopentenyl-methylhydrosilane by the intramolecular hydrosilylation catalyzed by chloroplatinic acid, and their structures were unquivocally assigned by 1H and 13C NMR spectra. Dramatic crossover from inversion to retention was found in the phenylation of chlorosilanes with phenyllithium and phenylmagnesium bromide in ether. Regio- and stereoselective insertion of dichlorocarbene generated from phenyl(bromodichloromethyl)mercury, or from chloroform and sodium hydroxide in the presence of a phase transfer catalyst, into C(6)–H(exo) bond of 2-silanorbornanes has been observed.
New Industrial Synthesis of Squalane
Authors: Nishida Takashi , Ninagawa Yoichi , Itoi Kazuo , Fujita Yoshiji
Published: July 2006

Squalane is synthesized by the ethynylation reaction of geranylacetone with a complex of 1,3-butadiyne : N-methylpyrrolidone (=1 : 1) in the presence of a KOH catalyst and by hydrogenation with a Raney nickel catalyst, followed by hydrogenation hydrogenolysis with a mixed catalyst of nickel/diatomaceous earth and silica-alumina. An alternative synthesis of squalane from dehydronerolidol is also achieved by oxidative coupling reaction with a copper(II) catalyst under a helium atmosphere.
Extraction–Spectrophotometric Determination of Molybdenum(V) with Imidoyl Derivatives and Thiocyanate
Authors: Patel Khageshwar Singh , Mishra Rajendra Kumar
Published: July 2006

Three new organic reagents derived from N-phenylbenzimidoyl chloride and thiourea, phenylthiourea or thiosemicarbazide react with Mo(V) in strongly acidic media in the presence of thiocyanate ions to give rise red-orange complexes, insoluble in water but soluble in benzene. The nature of the ligands has been described to be as univalent, bidentate chelating agents which may coordinate to Mo(V) to form complexes with the composition of Mo 0.2SCN·SR (SCN denotes thiocyanate ion and SR, deprotonated form of the reagents). The molar absorptivity of the complexes was found to be in the range of (0.8–1.4)×104 l mol−1 cm−1 at λmax, 465 nm. The method is simple, rapid and highly selective for Mo. The ferroalloy elements which are associated with the metal do not interfere with the determination. The method was applied to the analysis of ore and alloy steel samples for Mo.
Studies in Nickel(IV) Chemistry. Kinetics of Electron Transfer from Hydrazine to Tris(dimethylglyoximato)nickelate(IV) in Aqueous Medium
Authors: Acharya Sridhara , Neogi Gautam , Panda Rama Krushna , Ramaswamy Dorai
Published: July 2006

Kinetics of electron transfer from hydrazine(L) to tris(dimethylglyoximato)nickelate(IV), [Ni(dmg)3]2−, follow pseudo-first-order disappearance in the Ni(IV) in aqueous medium in the range 5.0≤pH≤7.0. The pseudo-first-order rate constants (kobsd) increase with increasing [L]0 and attain limiting values at higher relative [L]0. The kobsd-pH profiles at various [L]0 show that the kobsd values register steep decrease with increasing pH till pH≈6.5 tending to level off at higher relative pH. Results are consistent with probable interactions of the one-protonated and two-protonated Ni(IV) species with the protonated substrate, or with the metal ion-substrate complex that might have been formed from trace metal ion and the substrate. The two-protonated Ni(IV) complex apparently reacts several orders of magnitude faster than the one-protonated species.
A New Series of Heptamolybdonickelate(IV) and Manganate(IV). Investigation of the Unusual Magnetic and Electronic Spectral Behavior of the Nickel(IV) Compound
Authors: Roy Ajoy , Chaudhury Muktimoy
Published: July 2006

Two new heteropolymolybdates of nickel(IV) and manganese(IV) of composition K2H8NiMo7O28·6H2O and K2H8MnMo7O28·4H2O with a hitherto unknown 1 : 7 (Ni/Mn : Mo) stoichiometry are reported. X-Ray powder patterns show that they are isomorphous. The electronic spectrum of the nickel(IV) compound exhibits four absorption bands at 16.4, 17.5, 18.3, and 24×103 cm−1, and the room temperature magnetic moment of the compound is abnormally high, 1.78 μB. The rationale for these observations is that there are Ni3+ impurity which occupy interstitial positions in the crystal lattice and as a consequence of dynamic Jahn-Teller distortion the high-spin 4A2g(4T1g) state of the Ni3+ ion lies close to the low-spin ground state 2A1g(2Eg) to get thermally populated to an appreciable extent leading to significant triplet state contribution.
Heats of Solutions of Bolaform Electrolytes in Water
Authors: Tamaki Kunio , Irie Kaoru
Published: July 2006

The heats of solutions of polymethylene-diammonium dichlorides [H3N(CH2)nNH3]Cl2 (n=2–8, 10, and 12) and disodium polymethylene disulfates Na2[O3SO(CH2)nOSO3] (n=2–6, 8, and 10) in water were measured at 15, 25, and 35 °C. The changes in the heat capacity for dissolution, ΔCpo, were obtained from the relation between the heats of soultion and the temperature, and the results were compared with the ΔCpo values for alkylammonium chlorides and sodium alkyl sulfates previously reported.
Studies of the Cobalt(III) Complexes of 8-Amino-3,6-diazaoctanate Ion. V. Optical Resolutions and Circular Dichroism Spectra of 8-Amino-3,6-diazaoctanato(glycinato)cobalt(III) Perchlorates
Authors: Watanabe Kiyokatsu
Published: July 2006

Three optically active isomers, (+)589-, (−)589-cis(O)-, and (−)589-trans(O)-[Co(adao)(gly)]ClO4, where adao and gly stand for 8-amino-3,6-diazaoctanate and glycinate, have been obtained. The structures have been determined on the basis of the absorption, circular dichroism, and proton NMR spectra.
Halogenation of Mixed Ligand Cobalt(III) Complexes with 12- or 13-Membered Tetraaza Macrocycle and Acetylacetone, [Co[Z]aneN4(acac)](ClO4)2 (Z=12, 13)
Authors: Hirano Akira , Matsumoto Naohide , Ohyoshi Akira
Published: July 2006

The parent cobalt(III) complex [Co[12]aneN4(acac)](ClO4)2, [Co[12]aneN4(bzac)](ClO4)2, or [Co[13]aneN4(acac)](ClO4)2 reacts with N-halogenosuccinimide to give the substituted complex [Co[12]aneN4(Xacac)(ClO4)2, [Co[12]aneN4(Xbzac)](ClO4)2, or [Co[13]aneN4-(Xacac)](ClO4)2, where [12]aneN4=1,4,7,10-tetraazacyclododecane, [13]aneN4=1,4,7,10-tetraazacyclotridecane, acac=acetylacetonato, bzac=benzoylacetonato, X=Cl, Br.
The Laser-flash Photolysis of 2-Hexanone and 5-Methyl-2-hexane for the Direct Detection of the Triplet 1,4-Biradical
Authors: Naito Ikuo
Published: July 2006

In the laser-flash photolysis of 2-hexanone and 5-methyl-2-hexanone (265 nm, 15 ns pulse), triplet 1,4-biradicals were detected directly. The absorption spectrum exhibits absorption maxima at λ=250 nm and at λ=320 nm. The decay-rate constant of the 1,4-biradical increases as follows: in methanol < in acetonitrile < in hexane < in dichloromethane [(2–4)×107 s−1 (2-hexanone), (3–6)×107 s−1 (5-methyl-2-hexanone)].
Synthesis of 3-(4-Piperidylidene)-1,3-dihydro-2H-indol-2-one Derivatives
Authors: Obase Hiroyuki , Nakamizo Nobuhiro , Takai Haruki , Teranishi Masayuki
Published: July 2006

3-[1-(2-Aryl-2-hydroxyethyl)-4-piperidylidene]-1,3-dihydro-2H-indol-2-one with structure II, as potential antihypertensive agent was synthesized. The intermediates, 3-[1-(2-aryl-2-oxoethyl)-4-piperidylidene]-1,3-dihydro-2H-indol-2-one (5) were prepared from 4-piperidone via 4 steps. Selective reduction of carbonyl group in 5 was realized using diisobutyl aluminium hydride to afford compound II.
Reaction of Some Compounds Having Both Endo and Exo Olefinic Bonds with 1,2,4-Triazoline-3,5-diones
Authors: Oshikawa Tatsuo , Yamashita Mitsuji
Published: July 2006

Reaction of piperitenone, (+)-limonene, or styrene with 1,2,4-triazoline-3,5-dione (TAD) produces adducts by ene reaction. The reaction of (+)-limonene gives a 2:1 adduct which results from further addition of TAD to an intermediary ene reaction product. The reaction of styrene gives 2:1 adducts via further addition of TAD to the Diels-Alder reaction product.
The η5-C9H11Fe(CO)2(isobutylene)+BF4− Complex as a Protecting Group of Carbon-Carbon Double Bonds
Authors: Ishii Yasutaka , Kagayama Takashi , Inada Akihiro , Ogawa Masaya
Published: July 2006

η5-C9H11Fe(CO)2(isobutylene)+BF4− (6), [Fpi(isobutylene)]+BF4−, was prepared and used as a protecting group of carbon–carbon double bonds. The complex 6 undergoes ligand exchange with a variety of diolefins to give Fpi(diolefin)+BF4− complexes, whose subsequent hydrogenations on Pd/C give olefins hydrogenated regioselectively.
Hydrocyanation of α,ω-Diynes Catalyzed by Tetracyanonickelate. Regiospecific Synthesis of a New Series of Acyclic Dinitriles
Authors: Funabiki Takuzo , Sato Yoshihiro , Yoshida Satohiro
Published: July 2006

Hydrocyanation of α,ω-diynes without the use of HCN has been described. Cyanonickelate, prepared by reducing [Ni(CN)4]2− with NaBH4 or Zn in the presence of excess KCN in water or ethylene glycol, catalyzes hydrocyanation of α,ω-diynes, HC≡C(CH2)nC≡CH to give quantitatively CH3CH(CN)(CH2)nCH(CN)CH3, a new series of acyclic dinitriles. Importance of the preliminary formation of a (π-acetylene)nickel(0) complex for the hydrocyanation has been suggested.
Synthesis of 2,9,23,30-Tetraoxa[2]paracyclo[2](1,1′)ferroceno[2]paracyclo[2](1,1′)ferrocenophane-1,10,22,31-tetraone
Authors: Kasahara Akira , Izumi Taeko , Saito Katsuo
Published: July 2006

Ferrocenophane, in which the two ferrocene rings are linked by ester bonds and p-substituted benzene rings, has been synthesized by the reaction of hydroquinone with 1,1′-bis(chloroformyl)ferrocene. The structure of the compound has been studied on the basis of the NMR and electronic spectra.
The Crystal and Molecular Structure of Echinosporin
Authors: Hirayama Noriaki , Iida Takao , Shirahata Kunikatsu , Ohashi Yuji , Sasada Yoshio
Published: July 2006

Echinosporin, 6-carbamoyl-1-hydroxy-3,5-dioxatricyclo[6.3.0.04,9]undeca-6,10-dien-2-one, is a novel antibiotic. The space group is P212121 with a=9.716(1), b=13.823(1), c=7.202(1) Å, and Z=4. The structure was solved by the direct method and refined to the R value of 0.049 by the block-diagonal least-squares method using 1239 reflexions. The molecule has a fused tricylo structure which consists of two six-membered rings and one five-membered ring.
Nitrite Substitution on cis-Tetraamminediaquacobalt(III) Ion in HNO2–NO2− Buffer Media
Authors: Ghosh Manik Chandra , Banerjee Pradyot
Published: July 2006

The anation of the title complex by NO2− was followed spectrophotometrically. The anation proceeds in two steps. A simple second-order rate law applies to each step. No evidence has been furnished for the formation of any nitrito intermeidates.
Ab Initio SCF-SDCI Prediction of Type II Spectra and Geometry of (ClHCl)− Hydrogen Bond Complex. I. One Dimensional Vibrational Analysis
Authors: Saitoh Toshikazu , Mori Kazuhide , Sasagane Kotoku , Itoh Reikichi
Published: July 2006

Ab initio SCF(self-consistent field)-SDCI(single and double configuration interaction) calculations are presented on HCl2−. Applied basis sets are 4-31G, 4-31G(**) (no 3d-polarization functions on Cl atoms and 2p-polarization functions on H atom), 4-31G** (addition of polarization functions both on Cl and H atoms) and the split basis by Dunning (Cl/12s9p)(H/4s)→[Cl/6s5p][H/2s] with the addition of diffuse functions and/or polarization functions. Vibrational and geometrical analyses are performed on the Cl–Cl potential surface under symmetry conservation, and then on the proton potential surface at optimized RCl–Cl position. After potential interpolation by the continuous quadratic functions which reconstruct the calculated potential values on all mesh points, the quantal vibrational analysis is perfomed by the Störmer-Levy difference method. Discussion is made on the experimental confusion about the assignment of type II spectra of HCl2− as v3 mode in an argon matrix by the selection of basis set and of CI matrix expansion. Whereas the calculations in a primitive size proposes the double minimum potential surface of proton and type II spectra in ≈700cm−1 region as v3 (which corresponds to the experimental data by Evans and Lo (1966) and Ault (1975)), the extended calculations (i.e. the large basis sets and the great number of CI matrix expansion) reduce the central barrier of the proton potential and then conclude the IR absorption in 1000–1100 cm−1 region as v3 in the type II spectra (which corresponds to the experimental results of CsCl·1/3 [H3O+HCl2−] by Schröder (1970) and Smith (1973)).
Demonstration of Electrostatic Field Effect Working on Dipolar Liquids with Correlation to Their Structures
Authors: Wada Goro , Teruta Yasuko , Kato Takako , Bitoh Naoko
Published: July 2006

When an electrically charged body is allowed to come close to a fine water stream falling down from the tip of a capillary, the vertical stream is bent a little to wards the charged body by an attractive force due to the electricity water dipole interaction. We constructed a simple equipment for the purpose of quantitative determination of the attractive force by defining a quantity P to search the correlation between the permittivity ε and the dipole momemt μ of polar liquids. For various pure polar liquids and mixtures at various mole fractions x of the components, we found a proportional correlationship P\barε=k\barμ with a common constant k, when the electric potential applied on an electrode, temperature, and flow velocity are fixed. In the cases of mixtures, \barε=∑x1ε1 and \barμ=∑x1μ1 are used. Pure liquids, such as methanol, ethanol, 1-propanol, acetic acid, acetone, acetonitrile, tetrahydrofuran, 1,4-dioxane, nitromethane, dimethyl sulfoxide, and nitrobenzene and mixtures, such as benzene–ethanol and benzene–nitrobenzene obey the proportionality rule approximately. On the other hand, water and some mixtures such as benzene–acetic acid and benzene–tetrahydrofran fail the rule, suggesting the possibility that molecular association occurs due to their mutual interactions in the liquids. Thus, this method may be considered as a simple demonstration illustrating the states of molecular aggregation in polar liquids.
The Synthesis of (+)-Premnolal
Authors: Matsumoto Takashi , Imai Sachihiko , Yuki Shuhei , Mitsuki Masanori , Miuchi Shigekazu , Sunaoka Yasuhiro
Published: July 2006

The revised structure of premnolal was confirmed by the following synthesis. Treatment of 12-methoxypodocarpa-8,11,13-triene (7), derived from methyl 12-methoxypodocarpa-8,11,13-trien-18-oate, with ethoxyoxalyl chloride and anhydrous aluminium chloride afforded 13-(ethoxyoxalyl) derivative, which was converted into 12-hydroxypodocarpa-8,11,13-triene-13-carbaldehyde (9) by alkaline hydrolysis, decarboxylation, and demethylation. The compound 9 was also prepared from 7 by demethylation and formylation. Reduction of 9 with lithium aluminium hydride, followed by partial acetylation, afforded 13-acetoxymethyl derivative which was converted into 13-acetoxymethyl-12-methoxy-11-nitropodocarpa-8,11,13-triene by nitration and methylation. This was then converted into 11,12-dimethoxypodocarpa-8,11,13-triene-13-carbaldehyde (18) by a series of reactions: catalytic hydrogenation, diazotization, reduction with lithium aluminium hydride, methylation, and oxidation. Demethylation of 18 gave 11,12-dihydroxypodocarpa-8,11,13-triene-13-carbaldehyde, which was identical with natural premnolal.
Acidic and Catalytic Properties of Niobium Pentaoxide
Authors: Iizuka Tokio , Ogasawara Kazuharu , Tanabe Kozo
Published: July 2006

The surface acidic property of Nb2O5·nH2O and its catalytic activities for the isomerization of 1-butene, the polymerization of propylene and the dehydration of 2-butanol were examined. The activities were high on Nb2O5·nH2O evacuated at moderate temperatures(100–150 °C) in all of the reactions and decreased drastically on evacuation at higher temperatures (400–500 °C). The surface of Nb2O5·nH2O showed a strong acidic character (H0≤−5.6) even after heating in air at 100 °C, but the strong acid sites disappeared on heat treatment at higher temperatures. The active sites on the catalysts heat-treated at moderate temperatures were ascribed mainly to Brönsted acid sites on the basis of the IR study of adsorbed pyridine.
The Preparation and Some Properties of Potassium Tris(1,1′-ferrocenedicarboxylato)ferrate(III)
Authors: Nomura Tomoko
Published: July 2006

The K3[Fe(1,1′-ferrocenedicarboxylato)3] complex was synthesized. The infrared absorption bands of the ligand (parent) acid, its potassium and barium salts, and the complex were assigned in studying the nature of the oxygen-to-metal bond in the complex. The electronic absorption spectra of the ligand acid and the complex were also measured. The techniques of thermogravimetry (TG) and differential thermal analysis (DTA) were used to establish the thermal decomposition of the complex.
Alcoholysis Equilibria of Dialkoxydimethylsilanes Catalyzed by Iodine or Iodine Monobromide
Authors: Ito Katsuko , Ibaraki Takeshi
Published: July 2006

Iodine or iodine monobromide was found to be an especially favorable catalyst for the study of the alcoholysis equilibria of dialkoxydimethylsilanes by gas chromatography. Iodine monobromide was employed to promote the reactions associated with tertiary alcohols, and iodine was used for the other reactions. Eight alcohols were allowed to react with diethoxydimethylsilane, and successive equilibrium constants, K1 and K2 were determined at 20 °C. K1=2.36–2.75 and K2=0.66–0.69 (by the use of primary alcohols), K1=1.34–1.38 and K2=0.28–0.30 (secondary alcohols), and K1=0.15–0.16 (tertiary alcohols) were observed. These values express precisely the difference of reactivities of the three groups of alcohols with diethoxydimethylsilane. Out of the dialkoxydimethylsilanes used in this study, eight unreported compounds were isolated and characterized.
Normal Pulse Polarographic Study of the Electrode Reaction of Copper(II) Complexes with Ethylenediaminetetraacetic Acid(EDTA) and N-(2-Hydroxyethyl)ethylenediamine-N,N′,N′-triacetic Acid(HEDTA)
Authors: Yamaguchi Shuichiro , Matsuda Hiroaki , Ohsaka Takeo , Oyama Noboru
Published: July 2006

The normal pulse polarographic behavior of the Cu(II)–EDTA and –HEDTA complexes was examined in a wide range of pH values to elucidate the mechanisms of their electrode reactions and to evaluate the relevant electro chemical kinetic parameters. From analysis of the dependence of the half-wave potentials on the sampling time and the hydrogen ion concentration, it was shown that the reduction wave of the Cu(II)–EDTA complexes observed in the pH range of 2.0 to 9.5 at −0.1 to −0.5 V vs. SCE corresponds to the simultaneous reduction of four complex species, CuH3L+, CuH2L0, CuHL−, and CuL2−, where CuHpL(p−2)+ and L4− denote the protonated complex species with p protons and the unprotonated EDTA ion, respectively. The reduction wave of the Cu(II)–HEDTA complexes in the pH range of 3.0 to 9.0 at −0.25 to –0.4 V vs. SCE corresponds to the simultaneous reduction of two complex species, CuHL0 and CuL−, where L3− denotes the unprotonated HEDTA ion. The kinetic parameters of the corresponding complex species (i.e. the cathodic transfer coefficient and the standard rate constant of electrode reaction) were evaluated.
Asymmetric Reduction of Chiral Pyruvamide with Sodium Borohydride
Authors: Munegumi Toratane , Harada Kaoru
Published: July 2006

Several amides of pyruvic acid with (S)-amines were reduced with sodium borohydride (NBH) in several alcohols and N-[(R)-lactoyl]-(S)-amines were obtained in excess. When the reductions were carried out in methanol or ethanol in the presence of metallic salt, N-[(S)-lactoyl]-(S)-amines were obtained in asymmetric yields up to 22%.
Revision of Structure of Anhydronellionol Triacetate
Authors: Matsumoto Takashi , Imai Sachihiko , Mitsuki Masanori , Maeta Seiji
Published: July 2006

The structure of anhydronellionol triacetate was revised to 11,12,16-triacetoxy-6-hydroxyabieta-5,8,11,13-tetraen-7-one (18) by the following syntheses. Acetylation of 16-acetoxyabieta-8,11,13-trien-12-ol, followed by oxidation with chromium trioxide, afforded 12,16-diacetoxyabieta-8,11,13-trien-7-one. This was converted into 6,12,16-triacetoxyabieta-5,8,11,13-tetraen-7-one (17) via 12,16-diacetoxyabieta-8,11,13-trien-6-one. Oxidation of 11,12,16-triacetoxyabieta-8,11,13-trien-6-one with Jones reagent gave 18, whose 1H NMR spectrum was in good agreement with that of natural anhydronellionol triacetate. 11,12,16-Triacetoxyabieta-5,8,11,13-tetraen-7-one (28) was also synthesized from 11,12,16-triacetoxyabieta-8,11,13-trien-7-one. The 1H NMR spectra of 17 and 28 were different from that of natural anhydronellionol triacetate. Since the revised structure 18 corresponds to dehydronellionol triacetate, the name of anhydronellionol should now be dropped from the list of natural diterpenes.
Conversion of Disilanes to Functional Monosilanes. XIII. The Palladium Catalyzed Reductive Coupling of Benzylidene Dichlorides and Benzylidyne Trichlorides Using Disilanes as Reducing Agents
Authors: Matsumoto Hideyuki , Arai Takeshi , Takahashi Masatoshi , Ashizawa Toshiyuki , Nakano Taichi , Nagai Yoichiro
Published: July 2006

The reaction of benzylidene dichlorides or benzylidyne trichlorides with 1,2-dichloro-1,1,2,2-tetramethyldisilane or hexamethyldisilane proceeded smoothly in the presence of acatalytic amount of Pd(PPh3)4 to give (E)-stilbenes or (E)- and (Z)-α,β-dichlorostilbenes in high yields, respectively. Also, in the presence of the palladium(0) catalyst, α,α-dichlorobenzyltrimethylsilanes reacted with hexamethyldisilane yielding (E)-α,β-bis(trimethylsilyl)stilbenes in quantitative yield.
The Crystal Structure of 2,11,20-Trithia[3.3.3](1,2,4)(1,3,5)cyclophane and Molecular Structures of Unsymmertically Tris-bridged[2.2.2](1,2,4)(1,3,5) and [2.2.2](1,2,4)(1,2,5)Cyclophanes, Estimated by Molecular Conformational Analysis
Authors: Kai Yasushi , Mizuma Takashi , Yasuoka Noritake , Kasai Nobutami
Published: July 2006

The crystal structure of 2,11,20-trithia[3.3.3](1,2,4)(1,3,5)cyclophane has been determined by the X-ray diffraction method and compared with the molecular structures of unsymmetrically tris-bridged [2.2.2](1,2,4)(1,3,5) and [2.2.2](1,2,4)(1,2,5)cyclophanes, estimated by molecular conformational analysis.
Kinetic Parameters of the Electrode Reaction of Carbonatocobalt(III) Complexes at Mercury Electrodes
Authors: Yamada Akifumi , Kado Yutaka , Yokoyama Yu
Published: July 2006

The electroreduction of [Co(CO3)(NH3)5]+, [Co(CO3)(NH3)4]+, [Co(CO3)(tn)2]+, [Co(CO3)(pn)2]+, [Co(CO3)(en)2]+, and [Co(CO3)2(en)]− (tn=trimethylenediamine, pn=propylenediamine, en=ethylenediamine) have been studied at mercury electrodes in weak acid solutions. All complexes exhibit two irreversible reduction waves; the first corresponds to CoIII→CoII, and the second, to CoII→Co0. The kinetic parameters of the electrode reactions of the first step were determined by means of Tast and pulse polarography in solutions containing 0.005 M sodium acetate-acetic acid buffer (pH=6) and 0.995 M sodium nitrate at 25 °C. The differential pulse polarograp hic characteristics of these complexes are also given.
Double Potential Step Chronoamperometry for Reversible Follow-up Chemical Reactions. Application to the Aquation Kinetics of Bis(ethylenediaminemonoacetato)cobalt(II)
Authors: Ohsaka Takeo , Sotomura Tadashi , Matsuda Hiroaki , Oyama Noboru
Published: July 2006

A theory of double potential step chronoamperometry (DPSCA) is developed for the reversible follow-up reactions represented as Ox+ne\ightleftarrowsRed, Red\oversetk\undersetkK\ightleftarrowsZ, where k and K are the rate and the equilibrium constants of the follow-up chemical reaction, respectively. DPSCA is applied to investigate the kinetics of aquation reaction of [Co(edma)2]0 (edma: ethylenediamine-N-acetate), which is produced by electrolytic reduction of [Co(edma)2]+ in the range of pH 1.5 to 10.5. At pH<4.5, the aquation reaction of [Co(edma)2]0 is irreversible. The rate of aquation reaction is accelerated by hydrogen ions and approaches an upper limiting value (2.1×103s−1). At pH>4.5,on the other hand, the hydrogen ions do not substantially contribute to the aquation and thus the rate approaches a lower limiting value (4.7×102s−1), which is in good agreement with that obtained in neutral region (4.5<pH<7), where the reverse (complex formation) reaction must be taken in to consideration. Above pH 7, the[Co(edma)2]0 species exists as main species in the solution and thus the kinetic behavior of the aquation is not observed. It is demonstrated that DPSCA is a useful method for kinetic studies of the dissociation-association reactions of labile complexes.
Synthesis of N-Unsubstituted Di- and Triaza Crown Ethers
Authors: Maeda Hirokazu , Furuyoshi Shigeo , Nakatsuji Yohji , Okahara Mitsuo
Published: July 2006

Facile syntheses of di- and triaza crown ethers by in tramolecular cyclization of oligoethylene glycols containing two or three imino groups or by their intermolecular cyclization with oligoethylene glycol bis(p-toluenesulfonate)s are described.
New Methods for the Synthesis of 3(2H)-Furanones and 2(5H)-Furanones
Authors: Saimoto Hiroyuki , Shinoda Masaki , Matsubara Seijiro , Oshima Koichiro , Hiyama Tamejiro , Nozaki Hitosi
Published: July 2006

New procedures for the synthesis of 3(2H)-furanones and 4-alkoxy-2(5H)-furanones are reported. Reaction of ketones with the lithium salt of propynal diethyl acetal, followed by treatment of the resulting 4-hydroxy-2-alkynal diethyl acetals with sulfuric acid–methanol, gave 2,2-disubstituted 3(2H)-furanones. The action of a polymer reagent Hg/Nafion-H upon 4–hydroxy-2-alkynones produced 2,2,5-trisubstituted 3(2H)-furanones. Reaction of 1,1,1-triethoxy-2-alkyn-4-ols (4) with trifluoroacetic acid and mercury(II) acetate provided 5-ethoxy-2,2-disubstituted 3(2H)-furanones. In contrast, the adducts 4 were converted into 4-alkoxy-5,5-disubstituted 2(5H)-furanones upon reaction with Hg/Nafion-H.
Phase Diagrams and Association Structures of Combined Surfactants–Water Systems
Authors: Sagitani Hiromichi , E. Friberg Stig
Published: July 2006

Phase regions were determined in systems with water and sodium dodecyl sulfate combined with a series of nonionic surfactants of the structure di-, tetra-, hexa-, and octaoxyethylene dodecyl ethers. The results showed the more hydrophobic members to act as cosurfactants, stabilizing the lamellar structure at high water contents. The more hydrophilic members of the nonionic series acted in a manner similar to ionic surfactants with a slight tendency to stabilization of the lamellar phase for 1:1 combinations of the surfactants.
Photoinduced Intramolecular Cyclization of 9-(ω-Anilinoalkyl)phenanthrenes
Authors: Sugimoto Akira , Sumi Katsumi , Urakawa Keiji , Ikemura Mamoru , Sakamoto Satoshi , Yoneda Shigeo , Otsuji Yoshio
Published: July 2006

Photoreactions of a series of compounds of the type 9-phenanthryl–A–CH2NHC6H5[–A–=o-phenylene (1b), –(CH2)2– (1c), –(CH2)3– (1d), –(CH2)4– (1e), –CH2– (1f)] in benzene were studied. From 1b–d, the spiro compounds are obtained by an intramolecular cis-addition of the N–H function to the C9, C10-double bond of the phenanthrene ring. These photoproducts can be converted to the starting materials by treating with trifluoroacetic acid or heating above their melting temperatures. The mechanistic features of these reactions are described.
Semiexperimental Magnetic Study of Some Methyl Derivatives of Benzoic Acid
Authors: Abdel-Kader Mohamed Mahmoud
Published: July 2006

The mean molar susceptibilities of some methyl derivatives of benzoic acid have been measured. From these measurements and the calculated value of the in-plane susceptibilities (K1, K2) of each molecule, the semiexperimental magnetic anisotropy of the acid molecule has been determined. The obtained magnetic data are explained on the basis of the hydrogen bonding systems of these molecules.
Capillary Ripple Response of Cholesterol and Lecithin Monolayers
Authors: Ahmad Jamil
Published: July 2006

Capillary ripple characteristics of monolayers of cholesterol and dipalmitoyllecithin and a 1 : 1 mixture of the two over air-water interface were studied. The ripple damping coefficient and the wavelength were determined as a function of the surface concentration. A stronger chain-chain interaction exists between the molcules in the pure cholesterol monolayer compared to pure lecithin as indicated by the sharp maximum in the damping coefficient curve for the former case. In the monolayer of the mixture, there is evidence of an interaction between the chains of the two substances.
Thermal Investigation of Nickel(II) Diamine Complexes in Solid State
Authors: De Goutam , Biswas Prasanta Kumar , Chaudhuri Nirmalendu Ray
Published: July 2006

Three tris(ethylenediamine)nickel(II) chloride dihydrate having identical composition, apparently similar in color, magnetic moment and spectral properties showed differences in thermal profile. Thermal investigations of [Ni(en)3]Br2·2H2O, [Ni(tn)3]Cl2·2H2O, and [Ni(tn)3]Br2·H2O where en=ethylenediamine and tn=1,3-propanediamine were carried out. Several bis and mono(diamine) complexes were synthesized in solid state from the corresponding tris complexes. All the bis and mono(diamine) complexes were found to be Oh hand Td symmetry respectively. All tris(diamine) complexes generate cis bis(diamine) species upon heating. But only one tris(ethylenediamine)nickel(II) chloride dihydrate generates cis bis species by the isomerization from the trans species temporarily formed. Monodiamine complexes decomposed through [Ni2(diamine)Cl4] species which showed unusually high magnetic moment. The probable mechanistic path for each step of decomposition was also reported.
Graphical Enumeration of the Sextet Polynomials. Novel Identities of Resonant Sextet Numbers of Cata-condensed Benzenoid Hydrocarbons
Authors: El-Basil Sherif
Published: July 2006

Novel graph-theoretical identities of resonant sextet numbers of certain nonbranched and branched cata-condensed benzenoid hydrocarbons are given, which are based on transforming Kekulé valence-bond structures into the subspace of their double bonds. Analytic expressions are given which allow construction of sextet polynomials of certain types of benzenoid hydrocarbons of very large sizes in a few seconds without drawing any graphs.
Wetting of Coal by Nonionic Surfactant and Mixtures of Nonionic and Anionic Surfactants
Authors: Esumi Kunio , Meguro Kenjiro , Honda Hidemasa
Published: July 2006

The rates of wetting of coals with various carbon contents by aqueous nonionic surfactants and mixtures of nonionic and anionic surfactants were examined. It was found that the wetting rate of each coal decreased with an increase of the length of oxyethylene chain in the nonionic surfactant. Further, the wetting rate of coal by anionic surfactant was enhanced by the addition of nonionic surfactant. This enhancement was most effective for coals with relatively low carbon content.
Distribution of Calcium Ion in the Crystal of MgTiO3–CaTiO3 System
Authors: Nagata Eiji , Tanaka Junzo , Tsutsumi Masayuki , Bannai Eisuke
Published: July 2006

The crystal of 0.96 MgTiO3–0.04 CaTiO3 was grown by a TSFZ method. The distribution of CaTiO3 in the crystal was analyzed by SEM and EPMA. The results obtained suggest that the change of dielectric properties of MgTiO3 by adding CaTiO3 results from the independent distribution of CaTiO3 in MgTiO3.
cyclo-Octasulfur in Swine Manure
Authors: Yasuhara Akio , Nagai Sumio , Fuwa Keiichiro , Jimbu Masayuki
Published: July 2006

Pale-yellowish white needles were isolated from a rotten mixture of swine urine and feces by vacuum distillation and identified to be cyclo-octasulfur by means of mass spectrometry and other methods. This is the first time that this compound has been detected in swine manure.
A Reinforced Oleophilic Anion-exchange Resin Membrane as a Sensitive Membrane of Anion-selective Electrodes
Authors: Jyo Akinori , Imato Toshihiko , Kohno Hirofumi , Ishibashi Nobuhiko
Published: July 2006

Based on an impregnation technique for the preparation of ion-exchange resin membranes, a simple way was proposed for the preparation of a reinforced oleophilic anion-exchange resin membrane as an anion-selective electrode membrane with a chemically fixed site. The resulting exchange resin membrane is thin (ca. 25 μm) and flexible. It gives anion-selective electrodes with high performances.
Metal Catalyzed Aquation of Tris(malonato)chromate(III)ion. Kinetics and Mechanistic Study
Authors: Basak Arup Kumar , Chatterjee Chinmoy
Published: July 2006

Metal ion catalyzed aquation of tris(malonato)chromate(III) ion has been followed spectrophotometrically in perchloric acid solution ([H+]=0.05 M) over a temperature range at an ionic strength of 2.0 M. Under these conditions kobsd=kH[H+]+kM[M2+] where kobsd is the observed first order rate constants for the protons and the metal ion catalyzed pathways. Metal ions exert appreciable catalytic effect on the aquation of the complex with kM following the sequence Cu(II)>Ni(II)>Co(II)>Zn(II)>Mn(II), which runs parallel to the metal monomalonato complex formation constants. A plausible mechanism for the metal promoted reactions is proposed.
Studies of Tritylated Pentoses and 6-Deoxyhexoses. III. The O-Tritylation of Methyl α- and β-d-Xylopyranoside
Authors: Otake Toshiki , Sonobe Toru
Published: July 2006

The tritylation of methyl α- and β-d-xylopyranoside afforded three isomeric trityl ethers in both cases. All the ethers were separated by column chromatography in almost pure forms on TLC. Among them, methyl 2-O-trityl-α- and methyl 3-O-trityl-β-d-xylopyranoside were crystallized from aqueous ethanol. The position of the trityl group in each ether was mainly established by the use of 1H NMR with its diacetyl derivative.
Condensations of 3,4-Bis(diphenylmethylene)-1,2-cyclobutanedione with o-Phenylenediamine under Ionic and Radical Reaction Conditions
Authors: Ro Zaiko , Tanaka Koichi , Toda Fumio
Published: July 2006

The title condensations under ionic and radical reaction conditions gave 1,2-bis(diphenylmethylene)-1,2-dihydrocyclobuta[b]quinoxaline and 7,8-bis(diphenylmethylene)-7,8-dihydrobenzo[b][1,4]diazocine-6,9(5H,10H)-dione respectively.
Synthesis of Cyclic Imines Having Conjugated Exocyclic Double Bond
Authors: Nomura Yujiro , Bando Takashi , Takeuchi Yoshito , Tomoda Shuji
Published: July 2006

Cyclic imines with conjugated exocyclic double bond have been synthesized by the reaction of 1-pyrrolinetrimer or 2,3,4,5-tetrahydropyridine trimer with various aldehydes in methanol in moderate to decent yields.
Spectrofluorimetric Determination of Zirconium in Hafnium Metal with Salicylic Acid and Rhodamine B after Its Separation Using Chloroacetic Acid and Salicylic Acid
Authors: Ramakrishna T V , Subramanian M S
Published: July 2006

A spectrofluorimetric method is described for the determination of 2 to 16 μg of zirconium based on the formation of an ion-association complex with salicylic acid and Rhodamine B. Hafnium behaved similarly to zirconium, but the interference can be overcome by selective extraction of zirconium at pH 1.4–1.6 from 1 mol dm−3 chloroacetic acid medium into 0.3 mol dm−3 solution of salicylic acid in 2:3 mixture of isobutyl methyl ketone (IBMK) and chloroform. The spectrofluorimetric method in conjunction with the separation procedure has been used for the determination of 4.4 to 14.5% of zirconium in hafnium metal.
Conformational Analysis of Terphenyls by Photoelectron Spectroscopy
Authors: Kobayashi Tsunetoshi
Published: July 2006

Vapor phase HeI photoelectron spectra of o- and m-terphenyl were measured, and conformational analysis of biphenyl, o-, m-, and p-terphenyl was made by comparing the observed photoelectron spectral patterns with the calculated ones by the CNDO/S method, the inter-ring twist angles in these compounds being estimated to be around 40°, 60°, 40°, and 40°, respectively. The result that the inter-ring twist angles in o-terphenyl are far smaller than 90° is completely in contrast to the long believed perpendicular model of o-terphenyl suggested by the gas electron diffraction study.