bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Design of a New Fluorescent Barbiturate Receptor. Sensitive Detection of Barbiturates through Solvent Extraction
Authors: Aoki Izuo , Kawahara Yohko , Sakaki Toru , Harada Takaaki , Shinkai Seiji 
Published: August 2006

Abstract
A fluorescent receptor, N,N′-bis[6-[4-(1-pyrenyl)butanamido]-2-pyridyl]isophthalamide (2), was synthesized to develop a sensitive host–guest-type sensory system for barbiturates. 2 aggregates in cyclohexane and the pyrene fluorescence in 2 almost disappeared because of aggregation-induced concentration quenching. The addition of barbital to the cyclohexane solution of 2, which induced the deaggregation of 2 through complementary complexation with barbital, increased the fluorescence intensity at 378 nm by a factor of about 70-fold. The barbiturates in water could also be sensitively detected by 2 based on a liquid (water)–liquid (cyclohexane) extraction technique. In this system, 2 was essentially selective for barbiturates and no fluorescence response was observed for guests including a hydantoin skeleton. The analogue of 2, which has the N,N′-di-(2-pyridyl) terephthalamide skeleton, was also investigated as a fluorescent receptor for dicarboxylic acids.
Multicarbonylation of Cyclopentadienyl and Cycloheptatrienyl Anions by Fe(CO)5
Authors: Nakanishi Saburo , Hirano Takehiro , Moriuma Hiroshi , Shiomi Makoto , Otsuji Yoshio , Adachi Tomohiro 
Published: August 2006

Abstract
The reaction of cyclopentadienyl anions with Fe(CO)5 in the presence of acyl chlorides or carboxylic anhydrides gave cyclic acyliron complexes [η5-C5H4C(OCOR)=C(OCOR)CO]Fe(CO)2 via triple carbonylation of the anions and a double acylation. The structure of [η5-C5H4C(OCOCH2CH3)=C(OCOCH2CH3)CO]Fe(CO)2 thus obtained was confirmed by the X-ray analysis. Diastereomers of indenyl derivative [η5-C9H6C(OCOCH2CH3)=C(OCOCH2CH3)CO]Fe(CO)(P(OCH3)3) were prepared by substitution of CO ligand with trimethyl phosphite and the structure of the diastereomers were characterized by NMR spectroscopy using 2D technique. Treatment of cycloheptatrienyl anion with Fe(CO)5 and acyl chloride resulted in double carbonylation to give [η5-C7H6C(OCOR)=C(OCOR)]Fe(CO)2. The mechanism of the reaction is proposed.
Synthesis and Chiroptical Properties of Optically Active Polyamides Having anti Head-to-Head Umbelliferone Dimer as a Component
Authors: Adegawa Yutaka , Fang Lan , Nakamura Masataka , Hasegawa Masaki , Saigo Kazuhiko 
Published: August 2006

Abstract
Optically active polyamides having 2,4-dihydroxyphenyl groups in the side chain were synthesized by the ring-opening polyaddition reaction of (−)-anti head-to-head umbelliferone dimer with diamines, such as 1,6-hexanediamine, 1,4-phenylenediamine, m-xylene-α,α′-diamine, and piperazine. Chiroptical properties of the polyamides were elucidated on the basis of their circular dichroism (CD) spectra in solution and in the film state. The polyamide having a 1,4-phenylene moiety in the diamine component existed in an ordered conformation even in a neutral DMAc solution. Moreover, the polyamides having 1,4-phenylenediamine or piperazine as a component existed in an ordered conformation in the film state. The steric repulsion and/or hydrogen bonding of the para-hydroxyl group on the phenyl group in the side chain was found to play a significant role to reveal the ordered conformations.
Preparation and Luminescence Properties of Organic Thin Films Obtained by Vacuum Deposition of Poly(p-phenylene) Synthesized by Various Chemical Methods
Authors: Toshima Naoki , Asakura Toshihide 
Published: August 2006

Abstract
Various organic thin films were obtained by vacuum deposition of poly(p-phenylene) (PPP) synthesized by three different methods: Grignard coupling of p-dibromobenzene (PPP-Y), and two kinds of oxidative cationic polymerization of benzene (PPP-K by a CuCl2–AlCl3 system and PPP-T by a CuCl–AlCl3–O2 system). The IR absorption band at 760 cm−1, which is attributed to a mono-substituted benzene ring, was stronger for the PPP thin films than that for the original PPP. The deposited thin films were partially soluble in THF and chloroform. The electronic absorption spectra of the PPP-K and the PPP-T thin film solutions had shoulders near 410 nm, while that of the PPP-Y film did not. The emission spectra had a peak at 375 nm for the PPP-K and the PPP-Y solutions. In contrast, the PPP-T solution had emission peaks at 465 and ca. 500 nm in addition to a peak at 380 nm, and the excitation spectrum for the peak at 465 nm was quite different from that for the peak at 380 nm. As for thin films, the PPP-K and the PPP-Y had emission peaks at 400—500 nm, while the PPP-T had an emission peak at 615 nm in addition to the peaks at 400—500 nm. The difference in the emission spectra is discussed in terms of the difference in contaminating by-products in the corresponding PPP.
Phosphate Ion Binding to α-Chymotrypsin
Authors: Ishimura Miyuki , Uedaira Hisashi 
Published: August 2006

Abstract
The spin-lattice relaxation times (T1) of 31P in α-chymotrypsin phosphate buffer solutions were measured as a function of the buffer concentration. The absorption isotherm of phosphate ions was obtained from the concentration dependence of 1/T1. The value of the equilibrium constant and the number of saturate sites were 66 and 42.
Effect of Temperature on Aggregation Structure of LB Film
Authors: Tone Seiji , Kunitake Masashi , Uchida Motoko , Kunitake Toyoki , Kajiyama Tisato 
Published: August 2006

Abstract
Molecular assembly of polymerizable amphiphile ([2-(acryloyloxy)ethyl][10-[N-[1,3-bis(hexadecyloxycarbonyl)propyl]carbanoyl]decyl]dimethylammonium bromide, designated as dihexadecyl N-[11-[[2-(acryloyloxy)ethyl]dimethylammonio]undecanoyl]glutamate bromide, 2C16–l-Glu–C11N+Ac) in the LB film was investigated in the temperature range above and below of the crystal–liquid crystal phase transition on the basis of wide-angle X-ray diffraction measurements. The crystal–liquid crystal phase transition temperature, Tc was determined to be 323 k based on differential scanning calorimetry (DSC). The LB film was in the form of highly oriented bilayer lamella and hexagonally assembled cylinder (rod) structure below and above Tc of the LB film, respectively. The hexagonally assembled cylinder structure above Tc may be formed due to the reason why a hydrophobic part occupies much larger cross-sectional area in comparison with that of a hydrophilic part above Tc. The change of bilayer lamella-hexagonally assembled cylinder was thermally reversible beyond Tc.
A Major Factor Controlling the SERS Band Intensity of Pyridine Adsorbed on a Silver Electrode
Authors: Saito Hiroshi 
Published: August 2006

Abstract
SERS intensity of pyridine has been examined as a function of the amount of charge necessary for the formation of Ag atom during the ORC procedure in each of several electrolytes. The amount of the reduction charge was controlled so as to hold a constant value of around 50 mC cm−2. Although the efficiency of charge recovery in the reduction process with nonhalide ion was very poor compared with chloride ion, intense SERS bands as large as in the case of chloride ion were found even in the case of nonhalide ion.
Determination of Total Phosphorus in Biological Samples by Flow Injection Analysis with Spectrophotometric Detection
Authors: Munaf Edison , Hu Wenzhi , Haraguchi Hiroki 
Published: August 2006

Abstract
Flow injection analysis with spectrophotometric detection has been developed for the determination of phosphorus in biological samples. Potassium peroxodisulfate was used as an oxidizing reagent with aid of a platinum wire as the catalyst, and organophosphorous compounds were converted to orthophosphate which reacted with ammonium molybdate in the presence of ascorbic acid to form the molybdenum blue complex. The absorbance of the complex was detected at 880 nm.
Analysis of Trace Moisture in HCl by Gas-Phase FTIR
Authors: Miyazaki Keiji , Ogawara Yoshimasa , Kimura Takako 
Published: August 2006

Abstract
Calibration of moisture in HCl in the sub-ppm range was performed by gas-phase FTIR spectroscopy, giving a linear correlation between infrared absorbance and the moisture concentration. Minimum detectability was estimated to be 30 ppb with 5-min scan time at 2 cm−1 spectral resolution at 1.6 kg cm−2 pressure, using an InSb detector and an 8-m-pathlength gas cell.
Formation of Carbon Films from C2H6–H2 by ECR Plasma CVD by Application of a Negative DC Bias
Authors: Maruyama Kazunori , Kamata Kiichiro , Yamamoto Masaki , Morinaga Toshiyuki , Kuchitsu Kozo 
Published: August 2006

Abstract
Hydrogenated amorphous carbon films were prepared from a C2H6–H2 system by ECR plasma CVD. A negative DC bias ranging 0 — −200 V applied to the ECR system induced an additional DC discharge to give an abrupt increase in the emission intensity of plasma beyond −110 V bias, where a soft (micro Vickers hardness of about 2 GPa) but flat surface with fine grains was formed.
Hydrogenation of α,β-Unsaturated Carbonyl Compounds by Carbon monoxide and Water with Rh6(CO)16 Catalyst under Mild Conditions
Authors: Joh Takashi , Fujiwara Keisuke , Takahashi Shigetoshi 
Published: August 2006

Abstract
By controlling such factors as the concentration of water and amine, the carbon–carbon double bond of α,β-unsaturated carbonyl compounds could be selectively hydrogenated under mild water–gas shift reaction (WGSR) conditions using a Rh6(CO)16–Et3N catalyst system. The reaction proceeded at room temperature under atmospheric pressure of CO.
Synergic Extraction of Lanthanoids(III) with 4,4,4-Trifluoro-1-(2-thienyl)-1,3-butanedione in the Presence of 1,10-Phenanthroline or 2,9-Dimethyl-1,10-phenanthroline
Authors: Nakamura Shigeto , Suzuki Nobuo 
Published: August 2006

Abstract
The synergic extraction of various tervalent lanthanoids (Ln(III)), La, Ce, Nd, Sm, Gd, Tb, Yb, and Lu, with 4,4,4-trifluoro-1-(2-thieny1)-1,3-butanedione (Htta) in the presence of a bidentate heterocyclic amine, 1, 10-phenanthroline (phen) or 2,9-dimethyl-1,10-phenanthroline (dmp), in benzene was investigated. In the phen system, a synergic enhancement occurred by the formation of the adducts, Ln(tta)3phen; the higher adduct, Ln(tta)3(phen)2, was found for La and Ce. In the dmp system, the formation of only one adduct, Ln(tta)3dmp, was observed. The values of the adduct formation constants (βs,1) for phen increase with increasing atomic number of Ln(III); those for dmp, however, decrease with increasing atomic number of Ln(III) and were lower than those for phen.
[2+3]-Type Addition Reactions of Benzocyclobutadiene with Nitrone Derivatives. Formation of Oxazolidine Derivatives
Authors: Saito Katsuhiro , Watanabe Hiroyuki , Sakura Michihito , Takahashi Kensuke 
Published: August 2006

Abstract
The reactions of benzocyclobutadiene with nitrone derivatives afforded oxazolidine derivatives through endo- and exo-[2+3]-type cycloadditions. The main formations of the endo-type adducts were explained by secondary orbital interactions in the transition states.
Ruthenium Catalyzed Dimerization of Trimethysilylacetylene to 1,4-Bis(trimethylsilyl)butatriene and Its Isomerization to (Z)-1,4-Bis(trimethylsilyl)-1-buten-3-yne
Authors: Wakatsuki Yasuo , Yamazaki Hiroshi , Kumegawa Nami , Johar Perminder S 
Published: August 2006

Abstract
Trimethylsilylacetylene was catalytically dimerized by Ru(cod)(cot)/PR3 (cod = 1,5-cyclooctadiene, cot = cyclooctatriene) to give either Me3SiCH=C=C=CHSiMe3 when PR3 = PPh3 or (Z)-Me3SiCH=CH–C≡CSiMe3 when PR3 = PBun3, the latter being formed by stereoselective isomerization of initially formed (Z)-Me3SiCH=C=C=CHSiMe3.
A Facile Preparation of Lithium Selenocarboxylates
Authors: Kojima Yoshihiro , Ibi Kazumasa , Kanda Takahiro , Ishihara Hideharu , Murai Toshiaki , Kato Shinzi 
Published: August 2006

Abstract
A series of lithium selenocarboxylates 2 were synthesized in good yields by the direct reaction of acyl chlorides with lithium selenide. The salts 2 were soluble in ether and tetrahydrofuran and readily reacted with alkyl iodides to give the corresponding Se-alkyl esters in quantitative yields.
Molecular Assemblies of Functional Molecules on Gold Electrode Surfaces Studied by Electrochemical Scanning Tunneling Microscopy: Relationship between Function and Adlayer Structures
Authors: Yoshimoto Soichiro 
Published: August 2006

Abstract
In this research, molecular assembly and function of aromatic thiols, porphyrins, phthalocyanines, and fullerenes on gold single crystal surfaces was studied by electrochemical methods and scanning tunneling microscopy (STM). Surface functions of promoter molecules such as pyridinethiols, pyrimidinethiols, and benzenethiol for cytochrome c electrochemistry were characterized by electrochemical techniques. Adlayer structures of those molecules were investigated by in situ STM, and molecular orientations for each molecule on the Au surfaces were clarified at molecular level. Adlayers of porphyrins and phthalocyanines for electrocatalytic reduction of dioxygen were examined to elucidate the relationship between activity and adlayer structure. Stable two-dimensional arrays of cobalt porphyrins indicated two-electron reduction of O2 to H2O2, whereas two-step four-electron reduction of O2 to H2O occurred because of highly mobile porphyrinatoiron molecules on the surface. Furthermore, well-defined adlayers of crown-substituted phthalocyanine for host–guest interface and binary array consisting of porphyrin and phthalocyanine for the design of supramolecular nanoarchitectures were clearly visualized by STM. Finally, a unique approach for controlling molecular orientation was found by the formation of supramolecular assemblies consisting of porphyrin and fullerene. The electrochemical redox reaction of carbonyl and ferrocene moieties was promoted by using the simple method for the construction of a 1:1 supramolecular assembled film consisting of C60 derivative and octaethylporphyrinatometal on Au single crystal surfaces.
Theoretical Study of Electronic Structures of [Peroxoporphinato]manganate [Mn(P)(O2)]− Anion
Authors: Yoshioka Yasunori , Sano Hideaki , Mitani Masaki 
Published: August 2006

Abstract
Geometries and electronic structures of the quintet and septet states of the [Mn(P)(O2)]− (P: porphinato) anion were theoretically investigated. Four local minimum geometries with two side-on additions of O2 to MnP, 1 (5B2) and 3 (7A2), and two end-on additions of O2, 2 (5A″) and 4 (5A′), were found. One of the side-on forms, 1, corresponds to that observed by X-ray crystallographic study. 3 is a septet state with higher spin than the quintet states of 1, 2, and 4. Each of the two end-on forms has the corresponding transition state with the side-on geometry. Energy differences among 1, 2, and 3 are less than 1 kcal mol−1. The electronic structures of four local minimum states were essentially different. 1 has an electronic structure presented as [MnIII(O22−)]−. 2 has antiferromagnetically coupled diradical character presented by the formal chemical formula of [MnII•(O2•−)]−. 3 has ferromagnetically coupled diradical character. 4 is presented by [MnII(O2−)]−.
Assay of Alkaline Phosphatase in Salmon Egg Cell Cytoplasm with Fluorescence Detection of Enzymatic Activity and Zinc Detection by ICP-MS in Relation to Metallomics Research
Authors: Hasegawa Takuya , Sugita Masaru , Takatani Kohei , Matsuura Hirotaka , Umemura Tomonari , Haraguchi Hiroki 
Published: August 2006

Abstract
Assay of alkaline phosphatase (ALP) in salmon egg cell cytoplasm was performed by size exclusion chromatography (SEC) with fluorescence detection of enzymatic activity and element-selective detection of zinc by ICP-MS, where 4-methylumbelliferyl phosphate (4-MUP) was used as the substrate for the enzymatic reaction of ALP. Two peaks were observed at retention times of ca. 21 and 27 min in the fluorescence-detected SEC chromatogram for salmon egg cell cytoplasm diluted 10-fold with 0.1 M Tris-HNO3 buffer solution, corresponding to the molecular weights (MWs) of ≥300 and 100 kDa, respectively. On the other hand, in the 66Zn-detected chromatogram for the same sample, a broad peak with a shoulder on the side of longer retention time was observed at ca. 21 min (MW≥300 kDa). When salmon egg cell cytoplasm was diluted 10-fold with pure water or 0.01 M Tris-HNO3 buffer solution, precipitation occurred. The supernatant obtained after filtration produced only one clear peak at a retention time of ca. 27 min in the fluorescence-detected chromatogram, at which the peak corresponding to zinc was also observed in the Zn-detected chromatogram. Therefore, the peak near 27 min was assigned to hydrophilic ALP in the salmon egg cell cytoplasm. Furthermore, the concentration of hydrophilic ALP (MW ca. 100 kDa) in the salmon egg cell cytoplasm was about 350 ng g−1, which was determined as an E. coli ALP-equivalent concentration by fluorescence intensity measurements.
Great Enhancement in the Oxidation Ability of Dilute Nitric Acid in Nanoscale Water-Droplets of Reverse Micelle Systems
Authors: Hojo Masashi , Ueda Tadaharu , Daike Chihiro , Takezaki Fumiko , Furuya Yumi , Miyamoto Kiyomi , Narutaki Akio , Kato Ryosuke 
Published: August 2006

Abstract
In reverse micelle systems, a large enhancement of the oxidation ability of dilute nitric acid was discovered, and its oxidation mechanism was explored. The Br− ion in the surfactant, CTAB, was oxidized to Br2 (or Br3−) in the CHCl3/CTAB/H2O reverse micelle system with W = 1.0–4.0 by diluted nitric acid (0.25–2.5 mol dm−3 in 1.0 vol % H2O portion) at 15–40 °C where CTAB stands for cetyltrimethylammonium bromide, and the W value is the ratio of [H2O]/[surfactant]. At higher concentrations of nitric acid and temperatures, faster reactions occurred. Otherwise, long reaction times were needed, e.g., 10 h for 1.0 mol dm−3 HNO3 at 25 °C. Light or ambient oxygen did not appear to affect the reaction. The ratio of produced Br2 or (Br3−) to the initial amount of HNO3 indicated the following reaction scheme: 2HNO3 + 2Br− → Br2 + NO2− + NO3− + H2O. The nitroyl ion (or nitronium ion), NO2+, was proposed as the intermediate active species. The addition of HClO4 as a proton source caused the complete reduction of N(V) as follows: NO3− + 6H+ + 5e− → 1/2N2 + 3H2O. The hydrogen-bonding structure of H2O in the CTAB or CTAC (cetyltrimethylammonium chloride) micelle system was found to be distorted, compared to that in bulk water, by the 1H NMR chemical shift of H2O. The change in 1H NMR chemical shift also demonstrated the consumption of protons during the oxidation of Br−, but not of Cl−, by dilute HNO3.
Palladium(II) and Palladium(II)–Platinum(II) Mixed Metal Complexes with Mercapto-1,3,4-thiadiazolate
Authors: Tannai Hidenori , Tsuge Kiyoshi , Sasaki Yoichi 
Published: August 2006

Abstract
Mononuclear and dinuclear Pd(II) complexes with mercapto-1,3,4-thiadiazolate were prepared by reacting [Pd(OH)(terpy)](PF6) with 2-amino-5-mercapto-1,3,4-thiadiazole (Hamct) and 2,5-dimercapto-1,3,4-thiadiazole (H2dmct). The reaction of [Pd(OH)(terpy)](PF6) and [Pt(Hdmct)(terpy)](PF6) resulted in the formation of the Pd(II)–Pt(II) heterometallic complex [{Pd(terpy)}(μ-dmct-S,S′){Pt(terpy)}](PF6)2, which showed that dmct2− can be utilized to prepare rationally heterometallic systems. Crystal structure analysis of the complexes showed that the ligands coordinate to the Pd(II) and Pt(II) centers by their mercapto groups in a κ1S coordination mode. The electronic spectra, redox properties, and molecular orbitals of the palladium complexes have been compared to those of Pt(II) congeners that we reported previously. The properties of a Pd(II)–Pt(II) mixed metal complex were elucidated based on the properties of each metal center.
Scavenging Effect of Precipitation on Volatile Organic Compounds in Ambient Atmosphere
Authors: Sato Emi , Matsumoto Kiyoshi , Okochi Hiroshi , Igawa Manabu 
Published: August 2006

Abstract
Hydrophobic volatile organic compounds (VOCs) are usually found in rainwater with higher concentrations than the values determined from Henry’s law partitioning. Laboratory experiments demonstrated that dissolved organic compounds, such as humic acids, act as cosolvents to solubilize the VOCs. Wet removal by rainfall is a significant sink of trace VOCs.
Crystalline Polymorphism of Bis[o-semibenzoquinonediimine(1−)]platinum(II)
Authors: Konno Yosuke , Matsushita Nobuyuki 
Published: August 2006

Abstract
A platinum complex with a non-innocent ligand, [PtII(L)2] (1), where L is o-semibenzoquinonediimine monoanion, has two polymorphs. In one polymorph, molecules related by translation are arranged in the same orientation along the c axis, while in the other, molecules related by a c-glide plane are aligned alternately in different orientation.
Photoreactivity of Tetra-Substituted Anthracene Derivatives and Their Mesophases
Authors: Yanagimoto Yasushi , Takaguchi Yutaka , Tsuboi Sadao , Ichihara Masahiro , Ohta Kazuchika 
Published: August 2006

Abstract
Novel tetra-substituted anthracene derivatives were synthesized, and their liquid crystallinities were characterized by using polarizing optical microscopy, DSC, and XRD. Although photodimerization of the anthracene derivatives proceed quantitatively upon irradiation with high-pressure mercury lamp in chloroform, the photoirradiation of the mesophases of these derivatives did not yield the corresponding photodimers. XRD analysis of the mesophases showed unusual stacking of anthracene moieties, which have insufficient orbital overlap. Structural analysis is consistent with the photoreactivity.
Lewis Base-Catalyzed [2,3]-Wittig Rearrangement of Silyl Enolates Generated from α-Allyloxy Carbonyl Compounds
Authors: Sato Yoshinori , Fujisawa Hidehiko , Mukaiyama Teruaki 
Published: August 2006

Abstract
Lewis base-catalyzed [2,3]-Wittig rearrangement of silyl enolates generated from α-allyloxy carbonyl compounds is described. The [2,3]-Wittig rearrangement of silyl enolates generated from α-allyloxy ketones proceeded smoothly by using a Lewis base catalyst, such as lithio or sodio 2-pyrrolidone, in DMF at room temperature without an accompanying [3,3]-Claisen rearrangement. The nature of the catalyst determines the pathway to proceed either by [2,3]-Wittig or [3,3]-Claisen rearrangement. In addition [2,3]-Wittig rearrangement of silyl enolates generated from α-allyloxy esters was tried. It was found that ammonium carboxylates, such as 4-methoxybenzoate, effectively promoted the reaction to afford the [2,3]-Wittig rearrangement product in good yield. This is the first example of the Lewis base-catalyzed [2,3]-Wittig rearrangement of silyl enolates generated from α-allyloxy carbonyl compounds.
Synthesis and Structures of 9-Triptycylallene Derivatives
Authors: Yamamoto Gaku , Kobayashi Yuriko , Ono Kasumi , Yano Emiko , Minoura Mao , Mazaki Yasuhiro 
Published: August 2006

Abstract
9-Triptycylallene (1) was synthesized by LiAlH4 reduction of 1-(9-triptycyl)-2-propynyl methanesulfonate (7), and three 3-substituted derivatives of 1 were also obtained by reacting compound 7 with appropriate metal reagents. LiAlH4 reduction of 1,3-di(9-triptycyl)-2-propynyl methanesulfonate (10) gave 1,3-di(9-triptycyl)propyne (12). The molecular structures of some of the allenes and of the propyne were determined by X-ray crystallography. As well, the allenes and some of the related compounds were characterized by NMR spectroscopy.
Synthesis and Characterization of a Fluorescein-Labeled Circular G-Quadruplex
Authors: Zhou Tianyan , Wang Yifan , Li Xinming , Zhang Qiang , Li Tianhu 
Published: August 2006

Abstract
A fluorescein-labeled circular G-quadruplex was readily synthesized chemically using a linear G-rich precursor. Hydrolysis tests and fluorescence spectroscopic examination confirmed that the product in our investigation has a circular backbone and possesses a fluorescein moiety.