bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Assembly of Bachteriochlorophyll a and Its Analogues by Synthetic 4α-Helix Polypeptides
Authors: Kashiwada Ayumi , Nishino Norikazu , Wang Zheng-Yu , Nozawa Tsunenori , Kobayashi Masami , Nango Mamoru
Published: December 2003

Molecular assemblies of bachteriochlorophyll a, BChl a and its analogues can be made due to the presence of synthetic 4α-helix polypeptides. UV-vis. and CD spectroscopic properties of BChl a derivatives were analogous to those obtained using light-harvesting (LH) polypeptides from photosynthetic bacteria. Thus, appropriate analogues of HAHA are useful in providing an insight into the structural effect of polypeptide on formation the LH / BChl a complex as well as an artificial LH complex model.
A Novel Naphthalocyanine Isomer: A Dinaphthophthalocyanine with C2v Symmetry
Authors: Miwa Hideya , Kobayashi Nagao
Published: December 2003

An adjacently dinaphtho-substituted phthalocyanine with C2v symmetry, which is a structural isomer of naphthalocyanines in the sense that eight benzene units are fused to the tetraazaporphyrin skeleton, has been synthesized and characterized by electronic absorption and magnetic circular dichroism spectroscopy, and molecular orbital calculations within the framework of the ZINDO approximation.
First Preparation and Structural Determination of Optically Pure Cyclic Polysulfides, 6,10-Diethyl Trithiolo[h]benzopentathiepin Monooxides
Authors: Kimura Takeshi , Kawai Yasushi , Ogawa Satoshi , Sato Ryu
Published: December 2003

Optically pure cyclic polysulfides, 6,10-diethyl trithiolo[h]benzopentathiepin 7-oxides (4) and (5) were prepared by asymmetric oxidation of 6,10-diethyl trithiolo[h]benzopentathiepin. The structure of 4 and 5 was determined by X-ray crystallographic analysis and the configuration was confirmed as R configuration on the sulfinyl sulfur atoms.
Insertion of Phenylacetylene into cis-Silyl(stannyl)platinum Complexes
Authors: Ozawa Fumiyuki , Sakamoto Yasunobu , Sagawa Takashi , Tanaka Rika , Katayama Hiroyuki
Published: December 2003

Silyl(stannyl)platinum(II) complexes cis-Pt(SiR3)(SnMe3)(PMe2Ph)2 (SiR3 = SiMe3, SiMe2Ph, SiMePh2, SiPh3) undergo insertion of phenylacetylene into the Pt–Si or Pt–Sn bond. The site selectivity dramatically varies with silyl ligands under kinetic conditions, while under thermodynamic conditions the insertion into the Pt–Si bond exclusively takes place irrespective of silyl ligands.
The Fast Photochemical [2+2] Cycloaddition and Reverse Reaction of a Styrylpyrazine Amphiphile in Aqueous Dispersion
Authors: Park Jong-mok , Zhang Wanbin , Nakatsuji Yohji , Majima Tetsuro , Ikeda Isao
Published: December 2003

Photochemical [2+2] cycloaddition of styrylpyrazine amphiphile 1 in aqueous dispersion occurred quantitatively and much faster than that of stilbene analogue 2. Amphiphile 1 showed intermolecular photoreversible reactivity, [2+2] cycloaddition and the reverse reaction, in aqueous dispersion with alternate irradiation at above 300 and at 254 nm as the first example for 1,2-diarylethylene in aqueous dispersion.
Novel High Performance ansa-Zirconocene Catalysts for Isospecific Polymerization of Propylene
Authors: Yamazaki Hiroshi , Kimura Keisuke , Nakano Masato , Ushioda Tsutomu
Published: December 2003

The introduction of furyl groups to the position next to the silylene bridge of an ansa-zirconocene catalyst was found to remarkably enhance the catalytic activity and the molecular weight of PP during the isospecific polymerization of propylene.
3-Isopropylidenemalic Acid: A Mechanism-based Inhibitor of 3-Isopropylmalate Dehydrogenase
Authors: Chiba Akira , Arai Noriko , Eguchi Tadashi , Kakinuma Katsumi
Published: December 2003

3-Isopropylidenemalic acid (1) was designed and synthesized as an inhibitor of 3-isopropylmalate dehydrogenase (IPMDH). While being weakly active as substrate, 1 appeared to be a mechanism-based inhibitor (KI = 60.2 μM) for IPMDH as deduced from the time-dependent and kinetic analyses.
Morinols A and B, Two Novel Tetrahydropyran Sesquineolignans with a New Carbon Skeleton from Morina chinensis
Authors: Su Bao-Ning , Takaishi Yoshihisa
Published: December 2003

Two sesquineolignans, each bearing a tetrahydropyran ring with a new carbon skeleton and named morinols A and B, have been isolated from the roots of a Chinese medicinal herb, Morina chinensis. Their structures have been determined on the basis of spectroscopic evidences, as well as a simple chemical transformation.
Lipase-Catalyzed Ring-Opening Polymerization of Cyclic Diesters
Authors: Müller Stephan , Uyama Hiroshi , Kobayashi Shiro
Published: December 2003

Ring-opening polymerization of cyclic diesters, ethylene dodecanedioate and ethylene tridecanedioate, took place using lipases as a catalyst under mild reaction conditions to give the corresponding polyesters with molecular weight of several thousands. Enzymatic polymerizability of these new monomers was compared with that of lactones.
Strong Basic Sites Accelerate the Deactivation of Oxide Catalysts Supported on FSM-16 for the Vapor-Phase Beckmann Rearrangement of Cyclohexanone Oxime
Authors: Shouro Daisuke , Nakajima Tsuyoshi , Mishima Shozi
Published: December 2003

The acidic and basic properties of FSM-16-supported Al2O3, ZnO or CdO were determined by the temperature-programmed desorption (TPD) of ethylamine. Relationship of the deactivation rate of the catalyst during the vapor-phase Beckmann rearrangement with the acidic and basic properties was studied. It was found that the deactivation was accelerated with an increase in the amount of the strong basic sites.
Selective Catalytic Dechlorination of Chloro Alkanes over Iron-based Catalysts
Authors: Lingaiah N , Uddin Md Azhar , Shiraga Yoshitaka , Tanikawa Hiroyuki , Muto Akinori , Sakata Yusaku , Imai Tomoyuki
Published: December 2003

A selective vapour phase dehydrochlorination (DHC) of chloro alkanes was achieved over a simple iron oxide catalyst system. The chloro alkanes were selectively dehydrochlorinated to their corresponding alkenes. This catalyst was also found to be effective for the removal of chlorine from fuel oil derived from the degradation of PVC containing waste plastics.
Electrochemical Copolymerization of Bithiophene and Aniline in Aqueous-Organic Mixed Solution
Authors: Hu Xiao , Wang Guang-Ming , Ng Hanwah , Wong Terrence KS
Published: December 2003

Polybithiophene (PBTh) and polyaniline (PAn) have been synthesized electrochemically in an aqueous-organic mixed solvent containing perchloric acid and acetonitrile. By using the mixed solvent system, the difference between the oxidation potentials of the two monomers is substantially reduced to 0.17 V from 0.55 V in pure acetonitrile organic medium. This enables the electrosynthesis of copolymer of bithiophene and aniline. Raman and absorption spectra were compared.
Regioregular Poly[2,5-bis(3-butyl-2-thienyl)tellurophene]: Synthesis and Characterization Aspects
Authors: Ng S C , Ding H , Chan H S O
Published: December 2003

This work reports on a novel, facile synthetic methodology into the tellurophene nucleus, which was applied in particular to the synthesis of the centrosymmetrical 2,5-bis(3-butyl-2-thienyl)tellurophene. Thereafter, oxidative polymerization of the monomer using iron (III) chloride afforded the regioregular poly[2,5-bis(3-butyl-2-thienyl)tellurophene]. Preliminary characterization aspects of the polymer are reported.
Photocatalytic Decomposition of Pure Water over NiO Supported on KTa(M)O3 (M = Ti4+, Hf4+, Zr4+) Perovskite Oxide
Authors: Mitsui Chiemi , Nishiguchi Hiroyasu , Fukamachi Keiko , Ishihara Tatsumi , Takita Yusaku
Published: December 2003

Photocatalytic decomposition of pure water on NiO supporting KTaO3 partially substituted with acceptor was investigated. Formation rate of H2 and O2 increased by partially substituting Ta with group 4 element. The increased photocatalytic decomposition activity by additives might be caused by a charge carrier annihilation.
New Calix[4]crown Diacylamides with Fluorescent Response to Complexation with Metal Ions
Authors: He Yong-Bing , Huang Huang , Meng Ling-Zhi , Wu Cheng-Tai , Yu Tian-Xiang
Published: December 2003

New calix[4]crowns having two acetaminoanthraquinone units at the lower rim have been synthesized; the intensity of their fluorescence spectra are markedly affected by alkali metal cation complexation.
Synthesis and X-Ray Crystal Structure of 27-Oxa-25,29-Dithiasapphyrin: Bithiophene-containing Sapphyrins Have an Inverted Structure
Authors: Shin Koo , Lim Choongsun , Choi Chonglak , Kim Youngmee , Lee Chang-Hee
Published: December 2003

Acid-catalyzed condensation of 16-oxa-5,10,15,17-tetrahydrotripyrrin and 5,5′-bis(tolylhydroxymethyl)-2,2′-bithiophene gives 5,20-ditolyl-27-oxa-25,29-dithiasapphyrin. The X-ray crystal structure revealed this sapphyrin derivative has an O-inverted structure.
Spatially Controlled Synthesis of Protein/Inorganic Nano-assembly: Alternate Molecular Layers of Cyt c and TiO2 Nanoparticles
Authors: Kimizuka Nobuo , Tanaka Masayoshi , Kunitake Toyoki
Published: December 2003

A molecular layer of Cytochrome c was self-assembled on two-dimensionally accumulated TiO2 nanoparticles, that have been deposited by hydrolysis of titanium hexafluoride in water. Repeated cycles of TiO2-deposition and cyt c-adsorption from aqueous phases afforded multilayered nano-assemblies, in which native spectral characteristics of cyt c was preserved.
Electroreductive Deposition of Au Clusters Modified with an Anthraquinone Derivative
Authors: Yamada Mami , Kubo Kenya , Nishihara Hiroshi
Published: December 2003

Anthraquinone derivative-modified Au clusters prepared by a substitution reaction of octyl thiolate-covered Au clusters with 1-(1,8-dithiaoctyl)anthracene-9,10-dione undergo a two-step one-electron reduction in aprotic solvents, resulting in the formation of an electroactive thin Au cluster film. Composite film formation is achieved by a combination of oxidative and reductive electrodeposition of biferrocene derivative-modified and anthraquinone derivative-modified Au clusters, respectively.
Recognition of Planar Chirality by Cyclodextrins
Authors: Kano Koji , Takaoka Ryoko , Sato Masayuki , Yamaguchi Masahiko
Published: December 2003

Recognition of planar chirality of 14-hydroxy-12-oxabicyclo[9.2.2]pentadecane-1(14),11(15)-diene-1,13-dione (C8) and 16-hydroxy-14-oxabicyclo[11.2.2]heptadecane-1(16),13(17)-diene-2,15-dione (C10) by native and O-methylated cyclodextrins has been studied by NMR spectroscopy. The cyclodextrins prefer the (R)-enantiomers of C8 and C10, which might well fit with asymmetrically twisted cavities of cyclodextrins.
A Novel and Efficient Deoxygenation of Hetero Cyclic N-Oxides Using ZrCl4/NaBH4
Authors: Chary K Purushothama , Mohan G Hari , Iyengar D S
Published: December 2003

A practical and novel reagent system ZrCl4/NaBH4 is used for the deoxygenation of N-Oxides to amines is described.
Ammonia Hydrothermal Treatment on Mesoporous Silica Structure Synthesized from Acidic Route
Authors: Lin Hong-Ping , Mou Chung-Yuan , Liu Shang-Bing
Published: December 2003

We report a post-synthesis procedure-ammonia hydrothermal treatment- to improve the structural features of surfactant-templated mesoporous silica synthesized from acidic route. The mesoporous products after this treatment become highly ordered and hydrothermally stable and the original hierarchical morphology are preserved.
Agostic Interaction in Formally Five-coordinate Hydridobis[1,3-bis(diphenylphosphino)propane]ruthenium(II) Ion
Authors: Saburi Masahiko , Fujii Tetsuya , Shibusawa Takayoshi , Masui Dai , Ishii Youichi
Published: December 2003

The molecular structures of [RuH(dppp)2]+ (1) and [RuH{OC(CH3)2}(dppe)2]+ (2) ions in the PF6− salts were determined by the X-ray crystallography. 1 involves the agostic interaction between the ortho C–H bond of a phenyl group of the dppp ligands and the formally unsaturated Ru center, and takes the cis geometry, where the terminal hydride and the agostic C–H moiety occupy the adjacent sites to each other. 2 adopts a typical octahedral six-coordinate structure with a coordinating acetone molecule trans to the hydride.
Highly Enantioselective Cyclopropanation of Styrenes with Diazoacetates Catalyzed by Optically Active β-Ketoiminato Cobalt(II) Complexes
Authors: Ikeno Taketo , Sato Mitsuo , Yamada Tohru
Published: December 2003

The highly enantioselective cyclopropanation of styrenes with diazoacetates was achieved using reasonably designed β-ketoiminato cobalt(II) complex catalysts. In the presence of optically active cobalt(II) complexes derived from optically active 1,2-(2,4,6-trimethylphenyl)-1,2-ethylenediamine, the cyclopropanation of styrene with methyl, ethyl, and tert-butyl diazoacetates proceeded to afford the corresponding cyclopropanecarboxylates with 94-96% ee.
A Supramolecular Ion Channel Based on Amphiphilic Cholic Acid Derivatives
Authors: Kobuke Yoshiaki , Nagatani Takeshi
Published: December 2003

Cholic acid was modified so as to represent the simplest expression of an artificial supramolecular ion channel by converting three hydroxyls to methyl ethers and a carboxyl to a methylene(trimethyl)ammonium grouping. It gave stable single channel currents showing several conductance values in planar bilayer lipid membrane.
Synthesis of [Al]-SSZ-31 by Dry-Gel Conversion (DGC) Method
Authors: Bandyopadhyay Rajib , Kubota Yoshihiro , Ogawa Masami , Sugimoto Noriaki , Fukushima Yoshiaki , Sugi Yoshihiro
Published: December 2003

Synthesis of large-pore zeolite [Al]-SSZ-31 has been studied by dry-gel conversion method using 1, 8-diazoniaoctane type of structure-directing agent. Pure SSZ-31 was obtained with NaOH/SiO2 = 0.05-0.12, while the product was contaminated with MFI below or above this range. Snowtex-40 (colloidal), as the silica source yielded SSZ-31, while Cab-O-Sil M-5 and Ludox AS-40 yielded mostly MFI phase. A phase change: BEA→SSZ-31→MFI was observed with time course at optimum NaOH/SiO2.
NMR Observation on Transbilayer Distribution of N-[13C]Methylated Chlorpromazine in Asymmetric Lipid Bilayer of Unilamellar Vesicles
Authors: Kobayashi Yoshimasa , Tachibana Kazuo
Published: December 2003

Unilameller vesicles of a suitable size for NMR resolution were successfully prepared with asymmetric bilayer in terms of the phospholipid composition. The preferred distribution of N-[13C]methylated chlorpromazine in the inner leaflet of these vesicles were directly observed by liquid NMR using a paramagnetic shift reagent in the external medium, verifying the bilayer couple hypothesis.
Sensitive ESR Determination of Intracellular Oxidative Stress by Using Acyl-Protected Hydroxylamines as New Spin Reagents
Authors: Itoh Osamu , Aoyama Masaaki , Yokoyama Hidekatsu , Obara Heitaro , Ohya Hiroaki , Kamada Hitoshi
Published: December 2003

Several acyl-protected hydroxylamines were synthesized as new spin reagents for ESR measurements of intracellular oxidative stress. These compounds were stable non-radical compounds, but were easily deprotected with esterase to yield hydroxylamines, which were oxidized by oxidants to yield ESR- detectable nitroxide radical. Using an acyl-protected hydroxylamine, a highly sensitive ESR determination procedure was successfully conducted to analyze oxidative stress in human leukocytes.
DNA Cleavage by a Polyethylenimine-appended Porphyrin
Authors: Suenaga Hikaru , Nango Mamoru , Sugiyama Tadatsugu , Iwasaki Toyota , Takeuchi Yoshito , Shinkai Seiji
Published: December 2003

Polyethylenimine (PEI)-appended porphyrin 2 bound DNA more strongly than non-polyethylenimine-appended porphyrins by creation of cationic charges of polyethylenimine and photochemically cleaved a double-stranded DNA.
Paecilospirone, a Unique Spiro[chroman-2,1′(3′H)-isobenzofuran] Derivative Isolated from Tropical Marine Fungus Paecilomyces sp.
Authors: Namikoshi Michio , Kobayashi Hisayoshi , Yoshimoto Takeshi , Meguro Shiori
Published: December 2003

A spiroacetal compound named paecilospirone was isolated from a marine fungus Paecilomyces sp. Collected at Yap Island. Paecilospirone was found by the screening assay for detecting inhibitors of microtubule assembly using conidia of Pyricularia oryzae. The structure was assigned based on the spectroscopic data. This is the first report of the isolation and characterization of spiro[chroman-2,1′(3′H)-isobenzofuran] derivative as a natural product.
Enormous Size Growth of Thiol-passivated Gold Nanoparticles Induced by Near-IR Laser Light
Authors: Niidome Yasuro , Hori Ayako , Sato Takuro , Yamada Sunao
Published: December 2003

Irradiation of pulsed 1064-nm laser light to dodecanethiol-passivated gold nanoparticles in cyclohexane resulted in enormous growth of the particles. The size increased up to ∼200 nanometers.
Sensitization of Europium(III) Luminescence by DTPA Derivatives
Authors: Ozaki Hiroaki , Suda Emiko , Nagano Toshihisa , Sawai Hiroaki
Published: December 2003

Novel ligands, diethylenetriaminepentaacetic acid bearing several aromatic amines, were synthesized and their chelates with a europium ion were prepared. The lanthanide luminescence of the chelates of 1-aminonaphthalene and 7-amino-4-methylcoumarin was largely enhanced by the energy transfer from the ligand to the europium ion.
Photooxidation of Methane to Methanol by Molecular Oxygen On Water-preadsorbed Porous TiO2-based Catalysts
Authors: Chen Xihui , Li Shuben
Published: December 2003

At the temperature below 350 K, methanol was formed from the photooxidation of CH4 by molecular oxygen on water preadsorbed porous TiO2-based catalysts, Mo-containing porous TiO2 catalysts exhibit higher catalytic activity than pure TiO2.
Highly Efficient Photon-to-Electron Conversion of Mercurochrome-sensitized Nanoporous ZnO Solar Cells
Authors: Hara Kohjiro , Horiguchi Takaro , Kinoshita Tohru , Sayama Kazuhiro , Sugihara Hideki , Arakawa Hironori
Published: December 2003

Mercurochrome showed efficient performance as an organic dye photosensitizer for a solar cell based on nanoporous ZnO thin film electrodes. A 2.5% solar energy conversion efficiency was accomplished under AM 1.5 (99 mW cm−2) with a short-circuit photocurrent density (Jsc) of 7.44 mA cm−2, an open-circuit photovoltage (Voc) of 0.52 V, and a fill factor of 0.64. A monochromatic incident photon-to-current efficiency (IPCE) reached 69% at 510 nm.
Enzyme-catalyzed Ring-opening Polymerization of β-Butyrolactone Using PHB Depolymerase
Authors: Suzuki Yoichi , Ohura Takeshi , Kasuya Ken-ichi , Toshima Kazunobu , Doi Yoshiharu , Matsumura Shuichi
Published: December 2003

Poly(3-hydroxybutyrate) [P(3HB)] was prepared by the ring-opening polymerization of (R,S)-β-butyrolactone (BL) using two types of PHB depolymerase with or without substrate-binding domains (SBD) as the catalyst. The SBD lacking PHB depolymerase exhibited better catalytic activities for the ring-opening polymerization of BL.
Morphological Behavior for Micelle from Polystyrene-b-poly[2-(β-d-glucopyranosyloxy)ethyl acrylate] upon Changing the Copolymer Concentration
Authors: Liang Yu-Zeng , Li Zi-Chen , Li Fu-Mian
Published: December 2003

Multiple morphologies of molecular assemblies of polystyrene-b-poly[2-(β-d-glucopyranosyloxy)ethyl acrylate] (PSt-b-PGEA) were obtained by initially dissolving it in DMF and then adding water to the organic solution. With increasing the initial copolymer concentration (ICC) from 0.1 wt% to 2.0 wt% in DMF, the molecular assemblies of PSt77-b-PGEA6 were transformed from spheres, to rods, to vesicles, to tubules, and again to vesicles. Concanavalin (Con A) was used to characterize the surface properties of the resulting aggregates.
Analysis of Two Stages Dehydrochlorination of Poly(vinyl chloride) Using TG-MS
Authors: Yoshioka Toshiaki , Akama Tetsuhiro , Uchida Miho , Okuwaki Akitsugu
Published: December 2003

Degradation behavior of poly(vinyl chloride) (PVC) was analyzed by means of simultaneous thermogravimetry-mass spectrometry (TG-MS). Weight loss and the production behavior of hydrogen chloride and organic materials with PVC degradation was clearly divided into three stages at lower heating rate. Dehydrochlorination was occurred mainly in the first and second stages. Benzene was formed mainly in the first stage with dehydrochlorination.
Conformational Dynamics of Alkyl Chains in the Lamellar Phase of a Nonionic Surfactant C12E3 Studied by Deuterium Nuclear Magnetic Resonance
Authors: Tonegawa Akimitsu , Ohno Keiichi , Matsuura Hiroatsu , Yamada Koji , Okuda Tsutomu
Published: December 2003

Deuterium NMR spectroscopy was applied to a study of conformational dynamics of alkyl chains in the lamellar phase of a C12E3 (nonionic surfactant)–water system. The order parameter derived has shown that addition of the surfactant in the lamellar phase causes conformational disordering of alkyl chains, leading to a transition to an isotropic solution phase, while addition of water, which eventually leads to phase separation, causes no substantial disordering of alkyl chains.
Lauryl and Stearyl Thioglycosides: Preparation and Reactivity of the Glycosyl Donor
Authors: Matsui Hideaki , Furukawa Jun-ichi , Awano Takuro , Nishi Norio , Sakairi Nobuo
Published: December 2003

Lauryl and stearyl thioglycosides were prepared by the Lewis acid catalyzed reaction of 1-O-acetylated sugars with non-volatile and almost odorless 1-dodecanethiol and 1-octadecanethiol, respectively. These thioglycosides were activated by N-iodosuccinimide-TfOH to glycosyl donors producing disaccharides in good yields.
Unexpected Formation of Novel [4.3.3]Propellane-type Trilactone by Dehydration of Aliphatic Tetracarboxylic Acid
Authors: Kato Jun , Kudo Kazuaki , Shiraishi Shinsaku
Published: December 2003

Dehydration of 3-carboxy-3-(carboxymethyl)hexanedioic acid with excess acetic anhydride resulted in the formation of a novel propellane-type trilactone (orthoester), 2,9,10-trioxa[4.3.3]propellane-3,8,11-trione. This is the first one-step synthesis of a propellane from an acyclic compound.
A Universal Topology in Nonlinear Electrochemical Systems
Authors: Li Zelin , Yu Yan , Liao Hua , Yao Shouzhuo
Published: December 2003

In this paper we present an interesting universal topology occurring in different kinds of electrochemical oscillatory systems, namely, a crossing cycle in the cyclic voltammograms, which means there are a pair of overlapping negative and positive nonlinear feedbacks. The topology can provide with a simple intuition prediction as to whether or not an electrochemical system is possible to oscillate with an appropriate choice of parameters.
Surface Properties of Polysilane Copolymers with Siloxane Pendant Groups
Authors: Matsukawa Kimihiro , Ishikawa Masami , Inoue Hiroshi
Published: December 2003

Polysilane copolymers with disiloxane pendant groups were prepared from methylphenyldichlorosilane and pentamethyldisiloxypropylphenyldichlorosilane as a comonomer by Wurtz coupling. Disiloxane pendant groups were accumulated at the surface of copolysilane films, which was evidenced by XPS analysis. Photoconductivity of these copolysilanes by Xerographic discharge measurement was not much affected by the disiloxane groups.
Improved Synthesis and Crystal Structure of TiCl3(tmeda)(thf): A Highly Stereoselective Pinacol Coupling Reagent for Aromatic Aldehydes
Authors: Oshiki Toshiyuki , Kiriyama Takayuki , Tsuchida Kazuaki , Takai Kazuhiko
Published: December 2003

A monomeric titanium(III) complex, TiCl3(tmeda)(thf) (1), has been prepared by a reaction of TiCl4 with TMEDA, Zn, and a catalytic amount of PbCl2 in an almost quantitative yield. The solid state structure of 1 is revealed by X-ray crystallographic analysis. The complex 1 couples aromatic aldehydes under mild conditions to give 1, 2-diols in good to excellent yields with high dl-selectivities.
Efficient Diastereoselective Pinacol Reaction of Aliphatic and Aromatic Aldehydes by Combined Use of Newly Utilized Titanium(II) Bromide and Copper
Authors: Mukaiyama Teruaki , Kagayama Akifumi , Igarashi Koji
Published: December 2003

Newly utilized low-valent titanium reductant, titanium(II) bromide, was conveniently prepared by treating titanium(IV) bromide with hexamethyldisilane. The pinacol reaction of aromatic and aliphatic aldehydes including primary aldehydes proceeded smoothly in dichloromethane-pivalonitrile at temperatures ranging from −23 to 0 °C by the combined use of soluble titanium(II) bromide and copper to give 1,2-diols in good to high yields with good to high dl-selectivities.
Photochemical Transformation of γ,δ-Unsaturated Ketone O-(p-Cyanophenyl)oximes to 3,4-Dihydro-2H-pyrrole Derivatives
Authors: Mikami Tetsuhiro , Narasaka Koichi
Published: December 2003

γ,δ-Unsaturated ketone O-(p-cyanophenyl)oximes are transformed to 3,4-dihydro-2H-pyrroles by the photosensitized electron transfer process.
Electrochemistry of Fullerene C60 Embedded in a Gel-like Membrane of Tetraoctylphosphonium Bromide on an Electrode in Aqueous Solution
Authors: Nakanishi Takashi , Murakami Hiroto , Sagara Takamasa , Nakashima Naotoshi
Published: December 2003

In this communication, we describe the first finding that fullerene C60 embedded in a gel-like membrane formed from tetraoctylphosphonium bromide on an electrode in an aqueous system gives stable electrochemistry leading to the formation of C60−, C602− and C603−.
Direct Observation of Conformers Caused by the Difference in Ligand Orientation in Low Spin Iron(III) Porphyrin Complex
Authors: Ikeue Takahisa , Yamaguchi Tatsuya , Ohgo Yoshiki , Nakamura Mikio
Published: December 2003

EPR spectrum of low spin bis(dimethylaminopyridine)(3,8,13,18-tetramesityl-2,7,12,17-tetramethylporphyrinato)iron(III) perchlorate taken in frozen CH2Cl2 solution at 4.2 K showed both large gmax and rhombic type signals. The result has been explained in terms of the presence of two conformers where the dihedral angles between two ligands are different.
TEM Observation of Interstratified Ni-Serpentine/Smectite Compounds
Authors: Nagase Takako , Ebina Takeo , Torii Kazuo , Iwasaki Takashi , Hayashi Hiromichi , Onodera Yoshio , Chatterjee Maya
Published: December 2003

Interstratified Ni-serpentine/smectite = 2/1 compound was described by transmission electron microscopy (TEM) for the first time. The image of the lattice fringe coincided with the result of simulation, and it is clearly different from that of chlorite/smectite = 1/1 mineral which has a similar periodicity in X-ray diffraction pattern. The image of domains curving to the direction of their serpentine-part, suggested that the surface of the particle was mainly consisting of Si-O sheets.
High Spin Molecules: [Mn12O12(O2CCH2Cl)16(H2O)4] and the One-electron Reduction Product [PPh4][Mn12O12(O2CCH2Cl)16(H2O)3]
Authors: Tsai Hui-Lien , Jwo Tyn-Yih , Lee Gene-Hsiang , Wang Yu
Published: December 2003

The complex of [Mn12O12(O2CCH2Cl)16(H2O)4] was reduced by PPh4I to give a reduced complex [PPh4][Mn12O12(O2CCH2Cl)16(H2O)3]. Crystal structures of both complexes were determined by the X-ray method. The dc magnetic susceptibility measurements indicate that the neutral and reduced complexes are high spin species.
Photochromism of Titanium Oxide Gels Prepared by the Salt-Catalytic Sol-Gel Process
Authors: Matsumoto Taki , Murakami Yasushi , Takasu Yoshio
Published: December 2003

Photochromism for the monolithic gel of titanium oxide prepared by the catalytic sol-gel process was observed. When hydrazine monohydrochloride was used as a catalyst, an intense blue color development was observed with the formation of Ti3+ on the irradiation of UV light (< ca. 350 nm). The degree of coloration and the recovery time were strongly affected by a kind of salt catalysts although the color was independent. Presence of active salt catalysts in the gel was indispensable for color development.
Encapsulation of Two Types of Chloroform Dimers in the Cavities of a Coordination Polymer
Authors: Biradha Kumar , Fujita Makoto
Published: December 2003

CHCl3 molecules were found to form two types of dimers via C-H···Cl and C-Cl···Cl-C interactions in the cavities of a coordination polymer. The Cambridge Structural Database studies indicated that the Cl···Cl dimer is the first example of CHCl3 with Cl to Cl distance (3.478(4), 3.501(3) Å) below the sum of the van der Waals radii of two Cl-atoms.
HPLC Enantioseparation with Cellulose Tris(3,5-dichlorophenylcarbamate) in Aqueous Methanol as a Mobile Phase
Authors: Chankvetadze Bezhan , Yamamoto Chiyo , Okamoto Yoshio
Published: December 2003

The appropriate design of mobile and stationary phase combinations allowed the use of cellulose tris(3,5-dichlorophenylcarbamate) (CDCPC) as the chiral stationary phase (CSP) in high-performance liquid chromatography (HPLC). Together with previous data obtained in n-hexane/2-propanol as a mobile phase the present study indicates very high chiral resolving ability of CDCPC.
Methylene Blue Sensitized Degradation of Sodium Hyaluronate through Photoinduced Electron Transfer
Authors: Kojima Masanobu , Takagi Tomoko , Matsubara Chie , Nakamura Kimitoshi
Published: December 2003

Sodium hyaluonate (NaHA) and Methylene Blue (MB) formed a complex through charge transfer (CT) interaction or ion association in aqueous solution. Irradiation of the complex using a 313-nm light under argon caused degradation of NaHA. The mechanism proposed on the basis of the effect of excitation wavelength and oxygen, and by comparison with the degradation of NaHA using Rose Bengal (RB) and TiO2, was that photoinduced electron transfer from NaHA to upper excited state MB initiated the degradation.
Hydrolysis of Oligonucleotides by Homogeneous Ce(IV)/EDTA Complex
Authors: Igawa Tomoyuki , Sumaoka Jun , Komiyama Makoto
Published: December 2003

Homogeneous Ce(IV) complex of EDTA promptly hydrolyzes oligonucleotides under physiological conditions. In contrast, dinucleotides are not hydrolyzed to measurable extents. The degree of polymerization of DNA substrate is crucial for the present catalysis.
A Simple Route to Selective Diels-Alder Reactions Using Modified Zeolite Y
Authors: Najafi H Mahmoudi , Ghandi M , Farzaneh F
Published: December 2003

Synthetically useful Diels-Alder reactions of different dienophiles with cyclopentadiene in the presence of chirally modified zeolite Y as simple and accessible medium led to high rate and diastereoselectivity and low to moderate enantioselectivity.
Color and Fluorescence Imaging with t-Boc-protected Dihydroxynaphthacenedione
Authors: Kim Jong-Man , Kim Jun-Young , Kim Tae-Ho , Han Dong Keun , Ahn Kwang-Duk
Published: December 2003

In recent years, generation of patterned images in polymer films has become a central focus in a variety fields of chemistry. Recently, generation of functional images by selective immobilization of organic dyes in the polymer film has been reported.1-3 Selective removal of acid labile protecting groups through photoinduced chemical transformation followed by chemisorption of organic dyes from solution into the patterned polymer film afforded µm-scale functional images.
Generation, Structure, and Reactivity of o-Iodobenzoyloxyl Radicals. Pulsed Laser Photolysis of 1-(o-Halobenzoyloxy)-2-pyridones
Authors: Hashimoto Ji-ichiro , Segawa Katsunori , Itoh Hiroki , Sakuragi Hirochika
Published: December 2003

The transient absorption spectrum of o-iodobenzoyloxyl radicals was observed for the first time in acetonitrile using 1-(o-iodobenzoyloxy)-2-pyridone as a precursor. On the basis of the comparison of the spectra of o-halobenzoyloxyl radicals, it is proposed that the o-iodobenzoyloxyl radicals take a planar structure with a strong interaction between the radical center oxygen atom and the neighboring iodine atom.
Photoinduced Deracemization of [Co(acac)3] (acac− = acetylacetonate) with Chiral Δ-[Ru(menbpy)3]2+ (menbpy = 4,4′-bis{(1R,2S,5R)-(−)-menthoxycarbonyl}-2,2′-bipyridine)
Authors: Hamada Taisuke , Ohtsuka Hiroshi , Sakaki Shigeyoshi
Published: December 2003

Deracemization of a racemic mixture of Δ- and Λ-[Co(acac)3] (acac− = acetylacetonate) was successfully carried out with a chiral ruthenium(II) complex, Δ-[Ru(menbpy)3]2+ [menbpy = 4,4′-bis{(1R,2S,5R)-(−)-menthoxycarbonyl}-2,2′-bipyridine], in acetnitrile-H2O (7:3 v/v), in the presence of either triethylamine or NaOH under visible light irradiation (420 < λ < 470 nm). The Λ-isomer was obtained preferentially with the enantiomeric excess of 38%.
The Juliá-Colonna Type Asymmetric Epoxidation Reaction Catalyzed by Soluble Oligo-l-leucines Containing an α-Aminoisobutyric Acid Residue: Importance of Helical Structure of the Catalyst on Asymmetric Induction
Authors: Takagi Ryukichi , Shiraki Akiko , Manabe Toshiki , Kojima Satoshi , Ohkata Katsuo
Published: December 2003

Length-defined organic solvent soluble oligo-l-leucines containing an Aib residue were prepared by stepwise elongation and fragment condensation methods, and were used as catalysts in the Juliá–Colonna asymmetric epoxidation reaction. The yield and enantioselectivity rose by increasing the number of amino acid units in the catalyst. The enantioselectivity was very sensitive to the reaction solvent. The IR characteristic bands (the amide I region) in CH2Cl2 indicated the soluble catalysts to be of helical structure in solution.
Highly Efficient Generation of Ammonium Eneselenolates, Their Reactions and Electronic Properties
Authors: Murai Toshiaki , Hayakawa Shuuya , Kato Shinzi
Published: December 2003

The ammonium eneselenolates generated from selenothioic acid S-esters and ammonium fluoride were reacted with carbon electrophiles to furnish ketene selenothioacetals with high stereoselectivities. The spectroscopic properties of the ammonium eneselenolates have suggested that the electrons on the selenium atom efficiently delocalize on the carbon-carbon double bond.
Properly Assembled Dendrons Can Be Immobilized into Dendrimers by in situ Cross-link
Authors: Numata Munenori , Ikeda Atsushi , Shinkai Seiji
Published: December 2003

Aggregates obtained from saccharide-containing dendrons were immobilized by in situ cross-link with 1,3-phenylene diisocyanate. Characterizations of the resultant oligomers by dynamic light scattering and MALDI-TOF Mass have established that the higher generation dendrons which tend to aggregate into a spherical structure result in a dendritic polymer whereas the lower generation dendrons which tend to aggregate into a disordered large particle cannot result in such a dendrimer-shaped oligomer.
Transesterification vs Hydrolysis: the Reactivity of Metal-Bound Hydroxo Moiety in [TPANi(II)(μ-OH)2Ni(II)TPA](ClO4)2 (TPA = tris(2-pyridylmethyl)amine)
Authors: Ito Masami , Kawano Hiroyuki , Takeuchi Takashi , Takita Yu-saku
Published: December 2003

In the reaction of triphenyl phosphate with ethanol in the presence of complex 1, the transesterification to give diethyl phenyl phosphate was observed, in which system direct nucleophilic attack of ligated hydroxo moiety in 1 toward triphenyl phosphate also proceeded to give µ-phosphate complex, 2.
A Photocrosslinkable Dendrimer Consisting of a Nucleobase
Authors: Tominaga Masahide , Konishi Katsuaki , Aida Takuzo
Published: December 2003

Upon irradiation at 280 nm in CH3CN, dendritic polyuracils LnU-OBn (n = 3, 4) were crosslinked by a [2+2] photodimerization of the uracil units to give intramolecularly “locked” dendrimers, which were unlocked by irradiation at 240 nm.
Photocatalytic Reduction of Acetylpyridine to Pinacol Using [fac-Re(bpy)(CO)3{4-(MeCO)py}]+ (bpy = 2,2′-bipyridine, py = pyridine)
Authors: Hori Hisao , Koike Kazuhide , Takeuchi Koji , Ishitani Osamu
Published: December 2003

[fac-Re(bpy)(CO)3{4-(MeCO)py}]+ can act as an efficient photocatalyst for the reduction of 4-acetylpyridine to a pinacol (py-CMeOHCMeOH-py) in the presence of triethanolamine. The reaction proceeds via formation of a pinacol complex [fac-Re(bpy)(CO)3(py-CMeOHCMeOH-py)]+.
Three-Dimensional Ordered Macroporous Structures With Mesoporous Silica Walls
Authors: Luo Qian , Li Li , Yang Bai , Zhao Dongyuan
Published: December 2003

Three-dimensional (3D) cubic ordered macroporous (140 nm) and binary macroporous (140, 80 nm) silica structures with ordered mesoporous (7.7 nm) walls have been synthesized by using cubic closed-packing colloidal crystals as templates. The colloidal crystals can be made from equal-sized or binary-sized latex spheres by the simple methods of self-sedimentation on the film or pressing into a pellet.
Decomposition of N-Nitrosamines over Zeolites
Authors: Shen Bin , Ma Li Li , Zhu Jian Hua , Xu Qin-hua
Published: December 2003

The strong adsorption of zeolite Y and ZSM-5 for N-nitrosamine such as N-nitrosodimethylamine and N-nitrosopyrrolidine was firstly revealed by use of adsorption, temperature programmed surface reaction and TG-DTA techniques. Zeolite can adsorb N-nitrosamines without interference of organic solvent, which will be helpful for removal of the N-nitrosamines pollution in environmental protection.
Low Temperature Synthesis of Titania Gel Containing Anatase and Rutile
Authors: Uekawa Naofumi , Kajiwara Jyunichi , Miyatake Kazuki , Kakegawa Kazuyuki , Sasaki Yoshinori
Published: December 2003

A crystallized titania gel was prepared without gel-collapse and precipitation by heat treatment at 348K for 24h of an aqueous ethanol solution of the Ti-peroxy compound obtained from Ti(OiPr)4 and H2O2. The structure of the TiO2 in the gel changed from rutile to anatase as the ethanol concentration in the gel increased.
Direct Observation of DNA Catenanes by Atomic Force Microscopy
Authors: Yamaguchi Hiroyasu , Kubota Kei , Harada Akira
Published: December 2003

Single molecular images of DNA catenanes have been clearly observed for the first time by AFM using a tapping mode at room temperature and in an ambient atmosphere.
Facile Preparation of a Fluorescence-labeled Plasmid
Authors: Ishii Tsuyoshi , Okahata Yoshio , Sato Toshinori
Published: December 2003

We developed a facile method for labeling plasmid DNA with a fluorescent probe (FITC). The obtained FITC-labeled plasmid kept luciferase activity, and had enough fluorescence intensity to monitor with flow cytometer and confocal laser scanning microscope.
Oscillatory Circulation of Copper Particles during Silver-Displacement Plating in a High Magnetic Field
Authors: Yonemochi Shin-ichi , Aogaki Ryoichi
Published: December 2003

Motion of copper particles during silver-displacement plating in a high magnetic field was investigated. Immediately after injecting a silver nitrate solution to a vessel filled with copper powder and suspending the powder in the solution, the particles start to circulate along a vessel under a vertical magnetic field with suddenly changing their directions. The velocity of the motion increased with the magnetic field strength though the deposition rate remained constant.
Synthesis of Silica-pillared Microporous Manganese Oxide
Authors: Liu Zong-huai , Ooi Kenta , Kanoh Hirofumi , Tang Weiping , Tomida Tahei
Published: December 2003

Silica-pillared layered manganese oxides with high surface area and high thermal stability have been synthesized for the first time by the two step intercalation of octylamine followed by tetraethylorthosilicate into birnessite type manganese oxide.
Low Thermal Conductivities of Undoped and Various Protonic Acid-Doped Polyaniline Films
Authors: Yan Hu , Ohno Naonori , Toshima Naoki
Published: December 2003

Thermal conductivities of undoped and various protonic acid-doped polyaniline films were measured by combination of a laser flash method and a scanning differential calorimeter. The thermal conductivities thus measured are in the range of conventional organic polymers, indicating that the doped polyaniline films have extremely low thermal conductivities among electrically conductive materials.
Fabrication of Two-Dimensional J-Aggregates on Au(111) Covered with Self-Assembled Cysteamine Monolayer
Authors: Sato Tomoo , Yamamoto Akihiro , Kawasaki Mitsuo
Published: December 2003

A simple and useful new method to fabricate high-quality 2D J-aggregates of anionic cyanine dyes on a solid surface has been established by using an Au(111) covered with cysteamine self-assembled monolayer. It was also found that this method allows easy control of dye aggregation ranging from a 2D crystalline J-aggregate to a high density of dye monomers without aggregation.
Preparation of Supported Gold Catalysts by Liquid-Phase Grafting of Gold Acethylacetonate for Low-Temperature Oxidation of CO and of H2
Authors: Okumura Mitsutaka , Haruta Masatake
Published: December 2003

Gold nanoparticles can be deposited on several metal oxides by liquid phase grafting (LG) of dimethyl gold acetylacetonate. They exhibit high catalytic activities for the oxidation of CO and of H2 at low temperatures, below and above 273 K, respectively.
Generation, Direct Observation and Kinetics of Triplet (2,4,6-Triisopropylphenyl)phenylcarbene
Authors: Hirai Katsuyuki , Yasuda Kentaro , Tomioka Hideo
Published: December 2003

The title carbene (2a) was generated and studied not only by product analysis but also by spectroscopic means. The results are compared with those observed for the corresponding tert-butyl analogue (2b), which revealed intriguing and unique natures required for kinetic protectors of triplet carbene.
Reduction of Sulfoxides to Sulfides Mediated by Ferrocene and Trifluoroacetic Anhydride
Authors: Kobayashi Kenji , Kubota Yasuo , Furukawa Naomichi
Published: December 2003

The reaction of diaryl sulfoxides with trifluoroacetic anhydride in the presence of ferrocene gives the corresponding sulfide. The reduction of sulfoxides composed of the ferrocene-spacer-methylsulfinyl triad system would proceed via a through-bond electron transfer rather than a through-space process.
Highly-Soluble Fluorocarbon Surfactant in Supercritical Carbon Dioxide: Effect of Counter Cation on Solubility
Authors: Kawakami Takanori , Saito Norio , Ikushima Yutaka , Liew Chee Chin , Aiba Keizo , Ohkawa Tadashi
Published: December 2003

We have developed a new series of branch-structured anionic surfactants dissolved significantly well in sc-CO2. We found that, the variation of counter ion species has a significant effect on the solubility of the surfactants in sc-CO2. Among these, the solubility of surfactant with ammonium ion exceeded 16 wt% at 40 °C and 15 Mpa, while that of surfactant with K+ was neglectable. This effect can be used for complete recovery of the surfactant.
A Novel Surface Modification of SnO2-Based CO Gas Sensors to Improve Temperature and Humidity Dependence
Authors: Morimitsu Masatsugu , Ozaki Yasutaka , Suzuki Sachiyo , Matsunaga Morio
Published: December 2003

A significant improvement in temperature and humidity dependence of SnO2-based CO gas sensors has been achieved by a novel surface modification with sulfuric acid, thiourea, ruthenium, and rhodium.
Electrical Properties of an Organic Conductor, β′- (BEDT-TTF)2ICl2 up to 10 Gpa
Authors: Adachi Takafumi , Ojima Emiko , Narymbetov Bakhyt Zh , Kobayashi Hayao , Miyazaki Takafumi , Tokumoto Madoka
Published: December 2003

Four-probe resistivity measurements were made on an organic semiconductor, β′-(BEDT-TTF)2ICl2 up to 10 Gpa by using a diamond anvil high-pressure cell. The activation energy was decreased with increasing pressure and the metallic phase appeared around 8 Gpa. When the pressure was kept around 10 Gpa, the resistivity was gradually increased with time, indicating an irreversible pressure-induced solid state transformation.
Photoluminescence Properties of Mo-MCM-41 Mesoporous Molecular Sieves and Their Photocatalytic Reactivity for the Decomposition of NOx
Authors: Higashimoto Shinya , Tsumura Rie , Zhang Shu Guo , Matsuoka Masaya , Yamashita Hiromi , Louis Catherine , Che Michel , Anpo Masakazu
Published: December 2003

Investigations of the mesoporous Mo-MCM-41 molecular sieves have shown that they include the tetrahedrally coordinated Mo-oxide species, which exhibits a photoluminescence spectrum attributed to the radiative decay from the charge transfer excited state. Also, the photocatalytic reaction of NO into N2 was found to proceed much more efficiently in the presence of propane than in the absence of propane. The dynamic quenching of the photoluminescence spectrum by the addition of NO or propane indicates that the excited state of the highly dispersed Mo-oxide species having a tetrahedral coordination plays a significant role in this reaction.
Synthesis and Spectroscopic Characterization of a Dawson Trivanadium-Substituted Polyoxotungstate-Supported {(Cp*Rh)2}4+ Complex; (Bun4N)5[(Cp*Rh)2P2W15V3O62]
Authors: Nomiya Kenji , Hasegawa Takeshi
Published: December 2003

A novel polyoxotungstate-based 2 : 1-type Cp*Rh2+ complex, (Bun4N)5[(Cp*Rh)2P2W15V3O62] (Cp* = C5Me5), was synthesized by a direct reaction of the Dawson trivanadium-substituted polyoxotungstate (Bun4N)9[α-1,2,3-P2W15V3O62] with an equimolar amount of [Cp*RhCl2]2 in ice-cooled CH2Cl2, without use of silver(I) salts to remove the chloride ions of the precursor.
Ligand Dissociation in the Excited State of 2-Thenoyltrifluoroacetonatoeuropium(III) Ion in Aqueous Solution
Authors: Tsukahara Satoshi , Fujiwara Mihoko , Watarai Hitoshi
Published: December 2003

In the emission decay kinetics of Eu(III)–2-thenoyltrifluoroacetone (Htta) aqueous system, we found out a new quenching mechanism due to the tta− dissociation from Eu(tta)2+ in the excited state. The mechanism well explained the double-exponential decay of the fluorescence observed in the Eu(III)-Htta system. The analysis of the decay curve observed at various temperatures gave the rate constants and thermodynamic parameters for the tta− dissociation from Eu(tta)2+.
193-nm Photoresists Based on Norbornene Copolymers with Derivatives of Bile Acid
Authors: Kim Jin-Baek , Lee Bum-Wook , Yun Hyo-Jin , Kwon Young-Gil
Published: December 2003

We synthesized new chemically amplified photoresists for 193-nm lithography. Norbornene substituted with a derivative of bile acid was copolymerized with maleic anhydride by free radical polymerization. The resulting copolymers have good transmittance at 193 nm and possess excellent thermal stability up to 260 °C. With the standard developer, the resists formulated with the copolymers form 0.15–0.18 µm patterns at doses of 6–7 mJ cm−2 using an ArF excimer laser stepper.
Preparation and Structure of a Dinuclear Iron(III) Complex with Six Terminally Coordinated Azides: A Precursor for Multidimensional Network
Authors: Nair Balachandran Unni , Weyhermüller Thomas
Published: December 2003

A novel dinuclear hexazido iron(III) complex of a binuclear macrocycle has been synthesized and characterized by its crystal structure determination.
Stereochemistry and Mechanism of Vinyl-migrating [1,2]-Wittig Rearrangement of α-Lithioalkyl Vinyl Ethers
Authors: Tomooka Katsuhiko , Inoue Tadashi , Nakai Takeshi
Published: December 2003

Enantiomerically defined α-stannylalkyl or α-methylbenzyl vinyl ethers, when treated with butyllithium, are shown to undergo the 1,2-vinyl migration to afford the allylic alcohols in almost racemic form in low or high yield, respectively, thereby proposing the radical cleavage-recombination pathway.
1H Spin-Lattice Relaxation Times of Water, Methanol, and Ethanol under Sub- and Supercritical Conditions
Authors: Tsukahara Takehiko , Harada Masayuki , Ikeda Yasuhisa , Tomiyasu Hiroshi
Published: December 2003

1H NMR spin-lattice relaxation times (T1) of water, methanol, and ethanol (abbreviated as W.M.E) were measured in the range of 25 to 400 °C at 30, 20, and 20 Mpa, respectively by using high-pressure NMR. It was found that the T1 values for each group of W.M.E increase with an increase in temperature up to around 220, 160, and 170 °C, and that above these temperatures, the T1 values decrease and approach a constant value at 300, 200, and 220 °C, respectively. It is explained that the spin-lattice relaxation (SLR) processes are dominated by the dipole-dipole (DD) mechanism at lower temperature and by the spin-rotation (SR) mechanism at higher temperatures. The reasons that the T1 values are nearly constant are supposed.
Effect of Heavy Ion Irradiation on Sucrose
Authors: Nakagawa Kouichi
Published: December 2003

Heavy ion irradiation of sucrose produces stable free radicals. The relative spin concentration obtained after the heavy ion irradiation increases linearly as the absorbed dose increases. It decreases logarithmically as LET (linear energy transfer) increases. Production of the relative spin concentration of He (helium) ion irradiated specimen was two times more dependent on LET than that for C (carbon) ion irradiation.