bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Transannular Interaction in [2.3]Metacyclophanes
Authors: Tsuge Akihiko , Yasutake Mikio , Moriguchi Tetsuji , Sakata Kazunori , Yamato Takehiko , Mataka Shuntaro , Tashiro Masashi 
Published: June 2004

Abstract
[2.3]Metacyclophanes(=MCPs) which carry various functional groups at their outer aromatic position have been synthesized. The transannular interaction between two aromatic rings of [2.3]MCPs estimated by their NMR and UV spectra has been proved to decrease in comparison with that of the [2.2]MCP system.
In Situ Raman Spectroscopic Investigation of Surface Redox Mechanism of Vanadyl Pyrophosphate
Authors: Koyano Gaku , Saito Takaya , Misono Makoto 
Published: June 2004

Abstract
The reversible oxidation and reduction of vanadyl pyrophosphate ((VO)2P2O7) to and from X1 phase of VOPO4 on the surface was demonstrated under the reaction conditions of n-butane oxidation by means of in situ Raman spectroscopy. This result combined with the previous ex situ studies1 indicates that this redox cycle is responsible for the catalytic oxidation to maleic anhydride.
Construction of Two-dimensional Single Crystal of Fatty Acid by Two-step Cooling Crystallization Method
Authors: Kuri Taishi , Muto Kiyoshi , Oishi Yushi , Suehiro Kazuaki , Kajiyama Tisato 
Published: June 2004

Abstract
A two-step cooling crystallization method for constructing two-dimensional single crystal of stearic acid was proposed on the basis of thermal characteristics of the monolayer on the water surface. The amorphous monolayer was cooled down to a higher crystallization temperature to form a small number of crystalline nuclei at the first step, and then, the monolayer was further cooled down to a lower crystallization temperature to form large crystallites at the second step. The crystallite size and the crystallographical regularity of the monolayer were remarkably progressed by the two-step cooling crystallization method.
An Asymmetric Synthesis of the ABC Ring System of 8-Demethyltaxoids from Optically Active 8-Membered Ring Compound via Intramolecular Aldol and Pinacol Coupling Reactions
Authors: Shiina Isamu , Nishimura Toshihiro , Ohkawa Naoto , Sakoh Hiroki , Nishimura Koji , Saitoh Katsuyuki , Mukaiyama Teruaki 
Published: June 2004

Abstract
Optically active novel taxoids were efficiently synthesized from 8-membered ring compound 3 by successive constructions of BC and ABC ring systems via each intramolecular aldol and intramolecular pinacol coupling reactions.
Photocatalytic Activities of Na2W4O13 with Layered Structure
Authors: Kudo Akihiko , Kato Hideki 
Published: June 2004

Abstract
Na2W4O13 with a layered structure possessed an energy gap between those of bulky WO3 and polyacid [Si(W3O10)4]4− photocatalysts and was active for photocatalytic hydrogen and oxygen evolution reactions in the presence of sacrificial reagents.
Reduction of Vanadium(IV) to Vanadium(III) by Cysteine Methyl Ester in Water in the Presence of Amino Polycarboxylates
Authors: Kanamori Kan , Kinebuchi Yoshiko , Michibata Hitoshi 
Published: June 2004

Abstract
The reduction behavior of vanadium(IV) by several thiolate compounds in water was investigated in the presence of amino polycarboxylates. Vanadium(IV) can be reduced by cysteine methyl ester in the presence of edta or cydta to yield [VIII(edta or cydta)(H2O)]−, respectively.
Asymmetric Intramolecular C-H/Olefin Coupling: Asymmetric Cyclization Reactions of 1,5-Dienes Catalyzed by Rhodium Complexes
Authors: Fujii Naoaki , Kakiuchi Fumitoshi , Yamada Airi , Chatani Naoto , Murai Shinji 
Published: June 2004

Abstract
Asymmetric intramolecular C-H/olefin coupling reactions of 1-(2-pyridyl)- or 1-(1- methyl-2-imidazolyl)-1,5-dienes are catalyzed by a rhodium complex having a homochiral monodentate phosphine ligand.
One-dimensional Chain and Discrete Trinuclear Compounds Derived from Assembly Reaction of [Mn(saltmen)(H2O)]ClO4 and K2[Hg(CN)4] {saltmen2− = N,N′-(1,1,2,2-tetramethylethylene)bis(salicylideneiminato) dianion}
Authors: Miyasaka Hitoshi , Matsumoto Naohide 
Published: June 2004

Abstract
The reaction of Mn(III) Schiff base complex [Mn(saltmen)(H2O)]ClO4 and [Hg(CN)4]2− gave two distinct compounds with respect to the formula ratio of Mn/Hg and structures, one is a 1-D polymeric compound [{Mn(saltmen)(H2O)}{Hg(CN)3}]n and the other is a discrete trinuclear compound [{Mn(saltmen)(H2O)}2{Hg(CN)4}]. These compounds were synthesized by making vary the ratio of mixing two building blocks.
Remarkable Viscoelasticity of Organic Solvents Containing Trialkyl-1,3,5-benzenetricarboxamides and Their Intermolecular Hydrogen Bonding
Authors: Hanabusa Kenji , Koto Chiemi , Kimura Mutsumi , Shirai Hirofusa , Kakehi Akikazu 
Published: June 2004

Abstract
Remarkable rise of viscosity was observed by adding trialkyl-1,3,5-benzenetricarboxamide into organic solvents; the formation of highly viscoelastic solution was discussed by viscosity measurement, FTIR spectroscopy, and X-ray molecular structure in the crystal.
Quantitative Analyses of Cieplak vs. Felkin-Anh Effects in Hydride Reduction of Cyclohexanone
Authors: Senju Takatoshi , Tomoda Shuji 
Published: June 2004

Abstract
Transition structures of LiH addition to cyclohexanone have been optimized at the B3LYP/6-31G* level. The bond lengths of the incipient bond become substantially elongated compared to the previous results at the HF/3-21G level. It has been revealed that both torsional effects and hyperconjugative stabilization are of less importance for the π-facial diastereoselectivity.
High Surface Area Smectite Supported Cobalt Oxides as Active Catalysts for Thiophene Hydrodesulfurization
Authors: Hayashi Eiji , Iwamatsu Eiji , Biswas Mohammad Elias , Ali Syed Ahmed , Yamamoto Yosuke , Sanada Yuzo , Lee Augustin K K , Hamid Halim , Yoneda Toshikazu 
Published: June 2004

Abstract
Cobalt oxide loaded on high surface area smectites are prepared and tested in a pulse flow reactor for thiophene hydrodesulfurization (HDS). Smectites used were montmorillonite, saponite, porous saponite, hectorite and stevensite. Co-porous saponite showed the highest activity among Co-smectites, Co/Al2O3, and CoMo/Al2O3 so far studied. It suggests that the property of smectite has an influence on the catalyst activity.
Influence of Micelles and Magnetic Isotopes on Magnetic Field Dependence of Lifetimes of Benzophenone Ketyl-Alkyl Radical Pairs
Authors: Fujiwara Yoshihisa , Yoda Kohji , Aoki Takeshi , Tanimoto Yoshifumi 
Published: June 2004

Abstract
Influence of micelles and magnetic isotopes on magnetic field dependence of lifetimes of benzophenone ketyl-alkyl radical pairs in micellar solutions was studied below 14 T. The lifetimes were dependent on micelles and independent of isotopes. The lifetimes of radical pairs are controlled by the electron dipole interaction of the radical pairs in &lt; 2 T and by the competition of anisotropic Zeeman interaction and the escape from the micelles in &gt; 4 T.
Iridium-Catalyzed Redistribution of Hydrodisilanes via a Silyl(silylene)iridium(III) Complex: Synthesis of a Donor-Stabilized Silyl(silylene)iridium(III) Complex
Authors: Okazaki Masaaki , Tobita Hiromi , Ogino Hiroshi 
Published: June 2004

Abstract
Thermolysis of HMePhSiSiMe3 in the presence of a catalytic amount of Ir{η2-Me2Si(CH2)2PPh2} (PMe3)3 resulted in the redistribution of substituents to give its isomer HMe2SiSiMe2Ph. We propose the mechanism involving the 1,3-Me-shift on a silyl(silylene) complex, which was trapped as a donor-stabilized silyl(silylene)iridium(III) complex.
High Resolution Adsorbent of Liquid Chromatography for Protein Analysis: Cattle Bone-Originated Hydroxyapatites Characterized by Heating
Authors: Akazawa Toshiyuki , Kobayashi Masayoshi , Kodaira Kohei 
Published: June 2004

Abstract
The functional spherical particles of cattle-bone originated hydroxyapatite (HAp) were prepared by a spray-drying method and they exhibited considerably higher resolutions and theoretical plate numbers for chromatographic separation of albumin and lysozyme than HAp synthesized from reagents. The chromatographic functions of particles were easily regulated by changing the heat-treatment temperature of HAp, resulting from the shift of the adsorption heat for the two proteins.
Cocrystals of Melamine and Succinimide: Supramolecular Lattice Structure Constructed with Both Self and Not-self Intermolecular Hydrogen Bonds
Authors: Tukada Hideyuki , Mazaki Yasuhiro 
Published: June 2004

Abstract
Melamine (M) and succinimide (S) give cocrystals in a 1:1 ratio, in which a supramolecular network is formed by multiple hydrogen bonds. The network in composed of two kinds of infinite links based on four molecular units, S-M-M-S; hydrogen bonds between the units to the a direction, and the π–π stacks in the c direction.
Controllable Orientation of the Peptide-Based Surfactant at Air-Water Interface
Authors: Toyotama Akiko , Kugimiya Shin-ichi , Yonese Masakatsu , Kinoshita Takatoshi , Tsujita Yoshiharu 
Published: June 2004

Abstract
A polypeptide-based amphiphile, poly(γ-methyl l-glutamate)-polyethyleneglycol block copolymer (PMG-PEG), formed a stable monolayer membrane at the air-water interface. The orientation of the α-helical amphiphile in the membrane was shown to be strongly dependent on the surface pressure.
Photochromism of Dinuclear Molybdenum Complexes with Disulfur and Ethylene-1,2-dithiolate Ligands
Authors: Shibahara Takashi , Iwai Nobuaki , Sasaki Mari , Sakane Genta 
Published: June 2004

Abstract
Photochromism was found out for a dinuclear molybdenum complex [Mo2(μ-S2)(μ-S2C2Ph2)2(S2C2Ph2)2] (1), and a similar complex [Mo2(μ-S2)2(μ-S4)(S2C2Ph2)2] (6) was found to show no photochromic property. On exposure to sunlight and halogen-lamp light, the color of solution of 1 changes from red-purple to gray. In the dark the color returns to red-purple.
A Novel Dinuclear Ru(II) Complex Having a Bridging Ligand of a Rigid and Extended Structure: Incorporation of an Anthraquinone Unit and Efficient Emission Quenching
Authors: Mishra Lallan , Choi Chang-Shik , Araki Koji 
Published: June 2004

Abstract
Dinuclear Ru(II) complex having extended conjugation within the bridging ligand was prepared by coupling of the Ru(II) polypyridyl complex having a benzoyl-substituted phenazine unit with diaminoanthraquinone in one step, in which emission from the excited Ru(II) center was efficiently quenched through the anthraquinone unit.
XPS Study of the Passive Layers Formed on Lead in Aqueous Nitrate Solutions
Authors: Uchida Miho , Okuwaki Akitsugu 
Published: June 2004

Abstract
The analysis of the lead surface immersed in aqueous nitrate solutions by X-ray photoelectron spectroscopy (XPS) shows the formation of passive oxide layer containing nitrogen compound. The oxide layer formed on the lead surface in aqueous ammonium nitrate solution was hydrolyzed and cracked.
Nonlinear Optical Responses of Dialkoxyazobenzene Isomers Adsorbed to Interface between Heptane and Viologen-Modified Quartz Plates
Authors: Yamada Keiji , Otsubo Hisaki , Yonemura Hiroaki , Yamada Sunao , Matsuo Taku 
Published: June 2004

Abstract
Surface SHG was observed, when a quartz plate with a submonolayer of viologen molecules on the surface was dipped into the heptane solution of 4,4′-dialkoxyazobenzene. Isomerization of the azobenzene moiety from the trans- to cis- form induced large increase in the SHG. The SHG was ascribed to intramolecular charge-transfer from the alkoxy- to the azo group of the non-centrosymmetrically aligned isomers on the quartz plate.
Nitration of N-Confused Porphyrin
Authors: Ishikawa Yuichi , Yoshida Ichiro , Akaiwa Kaori , Koguchi Eiji , Sasaki Takeo , Furuta Hiroyuki 
Published: June 2004

Abstract
The internal carbon of the inverted pyrrole in N-confused tetraphenylporphyrin 1 (5,10,15,20-tetraphenyl-2-aza-21-carbaporphyrin) was nitrated by using the following aqueous solutions at room temperature for several minutes; (1) NaNO2/HCl (yield 71%) and (2) 30 wt% nitric acid (yield 27%).
Stereoselective Luminescence Quenching in the Complex of Excited Triplet State of Δ-Tris(2,2′-bipyridine)ruthenium(II) with Optically Active Viologens in an Aqueous Solution
Authors: Tsukahara Keiichi , Kaneko Junko , Miyaji Tomoko , Hara Tomoko , Kato Masako , Kimura Masaru 
Published: June 2004

Abstract
Stereoselectivity was found in the intracomplex quenching process between the excited triplet state of Δ-tris(2,2′-bipyridine)ruthenium(II) and optically active viologen containing naphthyl group(s), where the bipyridine ligand interacts with the naphthyl group of viologen.
Photo-Oxidative Coupling of Methane over TiO2-based Catalysts
Authors: Okabe Kiyomi , Sayama Kazuhiro , Kusama Hitoshi , Arakawa Hironori 
Published: June 2004

Abstract
Oxidative coupling of methane was carried out under UV-irradiation at temperatures below 500 K. C2+ hydrocarbons were formed over TiO2 catalysts prepared from Ti(i-OPr)4 by hydrolysis. Correlation between C2+ selectivity and anatase fraction (%-anatase) of the catalysts was observed.
Selective Carbon-Bromine Bond Fission Induced by Non-Resonant Two-Photon (NRTP) Excitation of trans-4-Bromostilbene
Authors: Miyazawa Takashi , Liu Chengyou , Kira Mitsuo 
Published: June 2004

Abstract
Non-resonant two-photon (NRTP) excitation of a 1,4-dioxane solution of trans-4-bromostilbene induces selective homolytic carbon-bromine bond fission, in contrast to the corresponding single-photon (SP) excitation, where the cis-trans isomerization in predominant.
New Spiro Donor Molecules: Bis(tetrathiafulvalenyldithio)-methane and -germane
Authors: Ueda Kazumasa , Yamanoha Masaru , Sugimoto Toyonari , Fujita Hideo , Ugawa Akito , Yakushi Kyuya , Kano Kenji 
Published: June 2004

Abstract
As a new tetrathiafulvalene (TTF)-based donor molecule were synthesized spiro carbon and germanium compounds substituted with two tetrathiafulvalenyldithiolate groups. The redox processes were composed of two pairs of broad and reversible waves, each of which involves two electron transfer. The radical cations or bis(radical cation)’s generated by one- or two-electron oxidation were characterized by ESR.
The First Example of μ-Oxo-bis(μ-carboxylato)dioxovanadium(IV,V) Complex
Authors: Fukuda Izumi , Matsushima Hideaki , Maeda Kouichi , Koikawa Masayuki , Tokii Tadashi 
Published: June 2004

Abstract
A novel dinuclear oxovanadium(IV,V) complex, [(VO)2(O)(Ph2CHCOO)2(bpy)2]NO3·CH3OH (1), has been prepared. X-Ray structural analysis has revealed that 1 has a μ-oxo-bis(μ-carboxylato)-bridged structure. Magnetic susceptibility data for 1 show the paramagnetic behavior which is attributable to the d1-d0 system.
Formation of the He2(c,d,e,f,C,D,E,F) States by Ion-Ion Neutralization Reaction of He2+ with C6F6− in the Helium Flowing Afterglow
Authors: Tsuji Masaharu , Oda Erika , Tanaka Makoto , Nakamura Masafumi , Nishimura Yukio 
Published: June 2004

Abstract
The ion-ion neutralization reaction of He2+ with C6F6− has been spectroscopically studied in a He flowing afterglow. The He2(C,D,E,F,c,d,e,f) states in the energy range of 19.22-20.62 eV were produced. There was a great similarity in the product electronic state distribution between the He2+/C6F6− and He+/C6F6− reactions leading to He2* and He*, respectively.
The Role of Thermal Initiation in Nitroxide Mediated Living Free Radical Polymerizations
Authors: Veregin R P N , Kazmaier P M , Odell P G , Georges M K 
Published: June 2004

Abstract
The BPO initiated “living” polymerization of styrene in the presence of nitroxide is not consistent with the recently proposed steady-state mechanism, which requires constant nitroxide and polymer radical concentrations, and equal initiation and termination rates. It is shown that none of these conditions are met. The data is consistent with a polymerization rate that is dominated by nitroxide, not by the rates of thermal initiation and termination. Further, the use of agents that reduce thermal initiation shows that thermal initiation is not necessary to ensure that the polymerization proceeds, nor to ensure fast rates.
Mechanochemical Collapse of M41S Mesoporous Molecular Sieves through Hydrolysis of Siloxane Bonds
Authors: Tatsumi Takashi , Koyano Keiko A , Tanaka Yoshinori , Nakata Shinichi 
Published: June 2004

Abstract
The structural collapse of mesoporous molecular sieves MCM-48 and MCM-41 materials by mechanical compression was found to occur mechanochemically through the hydrolysis of Si-O-Si bonds. Their ordered structures were well retained by compressing the samples under dry N2.
Solid State Dye-Sensitized TiO2 Solar Cell with Polypyrrole as Hole Transport Layer
Authors: Murakoshi Kei , Kogure Ryuichiro , Wada Yuji , Yanagida Shozo 
Published: June 2004

Abstract
Solid type dye-sensitized solar cell was fabricated using photodepositing polypyrrole onto the surface of porous TiO2 electrode anchored by photosensitizing molecules of a ruthenium complex. Polypyrrole in the porous medium successfully works as hole transport layer connecting the sensitizer dye molecules to a counter electrode. Doping density of the polypyrrole conducting layer was optimized to improve the efficiency of the system.
Electrochemical Behavior of Hydrogen-Bonded Bilayers of Azobenzene Langmuir-Blodgett Film and Self-Assembled Monolayer on Gold
Authors: Zhao Chun-Xia , Zhang Jin , Liu Zhong-Fan 
Published: June 2004

Abstract
Langmuir-Blodgett (LB) monolayer of C8H17-C6H4-N=N-C6H4-O-(CH2)3-COOH (referred as ABD) was deposited on X-(CH2)2-SH self-assembled monolayer (SAM) modified gold electrode (X = COOH, OH), and hydrogen bond was created at the SAM-LB interface as evidenced by FTIR results. Electrochemical studies demonstrated that, different hydrogen bonding structures give different stabilities and redox behaviors.
Amberlyst A-21 an Excellent Heterogeneous Catalyst for the Conversion of Carbonyl Compounds to Oximes
Authors: Ballini Roberto , Barboni Luciano , Filippone Paolino 
Published: June 2004

Abstract
Oximes can be efficiently obtained at room temperature by simply dissolving the appropriate carbonyl compounds and hydroxylamine hydrochloride, in ethanol, with Amberlyst A-21 as catalyst. Good yields of oximes are obtained, in very short reaction times, even with polifunctionalized substrates.
Synthesis of Conjugated Rigid-Rod Polyarylenes with (η4-Cyclobutadiene)cobalt Moieties in the Main Chain
Authors: Rozhanskii Igor L , Tomita Ikuyoshi , Endo Takeshi 
Published: June 2004

Abstract
Ni(0)-promoted dehalogenation polycondensation of bifunctional (η5-cyclopentadienyl)(η4-cyclobutadiene)cobalt complexes yields rigid-rod π-conjugated polyarylenes, which exhibit the liquid-crystalline behavior both in melts and in solutions.
The Surface Capping of the CdS Nanoparticle with the Electroneutral Group of 2,2′-Bipyridine in AOT Reverse Micelle
Authors: Deng Huihua , Li Ming , Zhang Yu , Lu Zuhong , Fu Degang 
Published: June 2004

Abstract
The CdS nanoparticles capped with 2,2′-bipyridine (bpy) had been synthesized in AOT reverse micelle. Bpy molecules adsorb on the Cd2+-rich surface of the CdS cluster via the nitrogen σ donation, which was elucidated by the FT-Raman spectroscopy. AOT exists as an anion ion of AOTSO3− in the CdS/bpy composite.
Oxide Transfer Reaction from Carbonate to Metal-CO Complex, Affording Metal-η1-CO2 Complex and Carbon Dioxide
Authors: Nakajima Hiroshi , Tsuge Kiyoshi , Tanaka Koji 
Published: June 2004

Abstract
The unprecedented oxide transfer reaction from CO32− to the carbonyl complex, [Ru(bpy)2(CO)2]2+ in aprotic media is described. The oxide transfer proceeds via the 1:1 adduct formation, to afford Ru(bpy)2(CO)(η1-CO2) and CO2.
New Optically Active Diporphyrin Having a Chiral Cyclophane as a Spacer
Authors: Ema Tadashi , Misawa Shigeharu , Nemugaki Shuichi , Sakai Takashi , Utaka Masanori 
Published: June 2004

Abstract
Optically active dimeric porphyrin covalently linked by a chiral cyclophane was synthesized; the two porphyrin chromophores were disposed in a slipped cofacial fashion, which was found to be tunable by cooperative coordination of diamines with various chain lengths.
Umabanol, a New Tetracyclic Diterpene from a Marine Sponge
Authors: Tanaka Junichi , Nurrachmi Irvina , Higa Tatsuo 
Published: June 2004

Abstract
A new diterpene, umabanol, has been isolated from the sponge Epipolasis kushimotoensis and its structure determined by spectroscopic analysis. Umabanol possesses a new tetracyclic ring system related to verrucosane class diterpenes.
Catalytic Ability of Alkaline Phosphatase to Promote P-O-P Bond Hydrolyses of Inorganic Diphosphate and Triphosphate
Authors: Yoza Norimasa , Onoue Sumie , Kuwahara Yoshie 
Published: June 2004

Abstract
Alkaline phosphatase(EC3.1.3.1) catalyzed the hydrolyses of inorganic diphosphate(pyrophosphate) and triphosphate. The rate of P-O-P bond cleavage decreased with increasing pH at alkaline region, in contrast to the pH-dependencies of P-O-C and P-F bond cleavages. The enzyme was inactive toward cyclic triphosphate and, unlike well-known inorganic pyrophosphatase(EC3.6.1.1), was not inhibited by fluoride ion.
Enantioselective Borohydride Reduction of N-Diphenylphosphinyl Imines Using Optically Active Cobalt(II) Complex Catalysts
Authors: Sugi Kiyoaki D , Nagata Takushi , Yamada Tohru , Mukaiyama Teruaki 
Published: June 2004

Abstract
The enantioselective borohydride reduction using optically active cobalt(II) complex catalysts was successfully applied to various aryl N-diphenylphosphinyl imines, and the corresponding reduced products were obtained in good yields with high enantiomeric excesses (up to 99% ee). The optically active primary amines were obtained by the successive hydrolysis under mild conditions.
Dissymmetrical Photodimerization of Methyl 9-Anthroate
Authors: Noh Taehee , Lim Heejun 
Published: June 2004

Abstract
Irradiation of methyl 9-anthroate through a Uranium filter gave the 1,4-10′,9′ and 1,4-9′,10′ cyclodimers as well as the 9,10-10′,9′ cyclodimer; this is the first example of intermolecular photodimerization involving the 1,4,9′, and 10′ positions of meso-substituted anthracenes. These dissymmetrical cyclodimers were found to be thermally more labile than the 9,10-10′,9′ cyclodimer.
An Artificial Substrate for the Thermostable Farnesyl Diphosphate Synthase from Bacillus stearothermophilus
Authors: Nagaki Masahiko , Koyama Tanetoshi , Nishino Tokuzo , Shimizu Kanako , Maki Yuji , Ogura Kyozo 
Published: June 2004

Abstract
Desmethyl homologs of dimethylallyl diphosphate and of isopentenyl diphosphate were examined for the reactivity as substrates for the thermostable farnesyl diphosphate synthase of Bacillus stearothermophilus. E-But-2-enyl diphosphate was not accepted as a substrate at all, but but-3-enyl diphosphate reacted with dimethylallyl- and geranyl diphosphates to give norgeranyl- and norfarnesyl diphosphates, respectively, which lack methyl groups at the 3-positions.
Synthesis and Characterization of Thiophene 1-Oxides Kinetically Stabilized by Bulky Substituents at the 3- and 4-Positions
Authors: Nakayama Juzo , Yu Ting , Sugihara Yoshiaki , Ishii Akihiko 
Published: June 2004

Abstract
Oxidation of 3,4-di-t-butyl- and 3,4-di-1-adamantyl-, and 2,4-di-t-butylthiophenes with an equimolar amount of m-chloroperbenzoic acid in the presence of BF3•Et2O gave the corresponding thiophene 1-oxides in good yields, which are stable enough to be isolated in pure crystalline form. An X-ray single crystal structure analysis led to the conclusion that thiophene 1-oxides would not be aromatic.
Synthesis, Structure and Properties of [7]Heterohelicenes Possessing Phenolic Hydroxy Functions
Authors: Tanaka Kazuhiko , Kume Takuji , Takimoto Tadashi , Kitahara Yoshinori , Suzuki Hitomi , Osuga Hideji , Kawai Yasushi 
Published: June 2004

Abstract
Photocyclization of 2,7-bis[3-(t-butyldimethylsilyloxy)phenylvinylene]benzo[1,2-b:4,3-b′]dithiophene affords three regioisomers of the bis(silyloxy)[7]thiaheterohelicenes together with the unexpected 4-phenyl-substituted [7]thiaheterohelicene. Cleavage of the silyl ethers gave the helical quinone, which includes ethanol as guest molecules to form a 1:1 inclusion complex.