A5050754762- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Crystallography and molecular interactions
- Asymmetric Synthesis and Catalysis
- Analytical Chemistry and Chromatography
- Chemical Synthesis and Analysis
- Advanced Condensed Matter Physics
- Chemical Synthesis and Reactions
- Physics of Superconductivity and Magnetism
- Asymmetric Hydrogenation and Catalysis
- Carbon dioxide utilization in catalysis
- Magnetic and transport properties of perovskites and related materials
- Molecular spectroscopy and chirality
- Supramolecular Self-Assembly in Materials
- Iron-based superconductors research
- Ionic liquids properties and applications
- Surfactants and Colloidal Systems
- Image Processing Techniques and Applications
- Advanced Vision and Imaging
- Ferroelectric and Piezoelectric Materials
- Rare-earth and actinide compounds
- Thermal Expansion and Ionic Conductivity
- CO2 Reduction Techniques and Catalysts
- Synthetic Organic Chemistry Methods
- Liquid Crystal Research Advancements
Saitama University
2016-2025
Saiseikai Kumamoto Hospital
2021-2024
Osaka Ekisaikai Hospital
2022
Graduate School USA
2018-2021
Naga Municipal Hospital
2021
Shimizu (Japan)
2020
Nihon University
2018
Japan Atomic Energy Agency
2006-2014
Hirosaki Central Hospital
2013
Yokohama National University
2008-2011
An efficient organocatalytic system was developed for the synthesis of cyclic carbonates from epoxides and CO<sub>2</sub> (25–45 °C, 1 atm) in high-to-excellent yields (85–97%). Moreover, 2,6-pyridinedimethanol could be recycled several times without significant loss activity.
We report the observation of magnetic superstructure in a magnetization plateau state SrCu2(BO3)2, frustrated quasi-two-dimensional quantum spin system. The Cu and B nuclear resonance (NMR) spectra at 35 millikelvin indicate an apparently discontinuous phase transition from uniform to modulated near 27 tesla, above which 1/8 full saturation has been observed. Comparison NMR spectrum theoretical analysis Heisenberg model demonstrates crystallization itinerant triplets within large rhomboid...
We performed inelastic neutron scattering on the 2D Shastry-Sutherland system SrCu2(11BO3)2 with an exact dimer ground state. Three energy levels at around 3, 5, and 9 meV were observed 1.7 K. The lowest excitation 3.0 is almost dispersionless a bandwidth of 0.2 most, showing significant constraint single-triplet hopping owing to orthogonality neighboring dimers. In contrast, correlated two-triplet excitations 5 exhibit more dispersive behavior.
Giant negative thermal expansion is achieved in antiperovskite manganese nitrides when the sharp volume change associated with magnetic ordering broadened by substitution. In this Letter, we address unique role of ``magic'' element, Ge, for such broadening ${\mathrm{Mn}}_{3}{\mathrm{Cu}}_{1\ensuremath{-}x}{\mathrm{Ge}}_{x}\mathrm{N}$. We present evidence a local lattice distortion well described low-temperature tetragonal (${T}_{4}$) structure ${\mathrm{Mn}}_{3}\mathrm{GeN}$ range $x$, where...
We present a new series of polymer-ionic liquid solutions exhibiting LCST-type liquid-liquid phase separation behaviour, and reveal their behaviour intermolecular interactions based on diagrams NMR analysis.
Magnetic structures in an antiperovskite system, ${\mathrm{Mn}}_{3}{\mathrm{Cu}}_{1\ensuremath{-}x}{\mathrm{Ge}}_{x}\mathrm{N}$, with a large magnetovolume effect above $x=0.15$ have been studied by neutron powder diffraction measurement. The present study revealed that not only cubic crystal structure but also ${\ensuremath{\Gamma}}^{5g}$ antiferromagnetic spin are key ingredients of the this itinerant electron system. is possibly ascribed to geometrical frustration originating from...
Two new Pseudomonas species which were isolated from rice paddy and clinical specimens (groups Ve-2 Ve-1) are described. Strains of oryzihabitans sp. nov. yellow-pigmented, oxidase-negative, nonsporeforming, gram-negative, polarly monotrichously flagellated, rod-shaped organisms with deoxyribonucleic acid base compositions ranging 63.9 to 65.6 mol% guanine plus cytosine, ubiquinone Q-9, major cellular fatty acids consisting C18:1 acid, C16:0 C16:1 3-hydroxy 3-OH-C10:0 3-OH-C12:0 acid. this...
The cobalt complexes CoIIL1(PF6)2 (1; L1 = 2,6-bis[2-(2,2′-bipyridin-6′-yl)ethyl]pyridine) and CoIIL2(PF6)2 (2; L2 2,6-bis[2-(4-methoxy-2,2′-bipyridin-6′-yl)ethyl]pyridine) were synthesized used for photocatalytic CO2 reduction in acetonitrile. X-ray structures of 1 2 reveal distorted trigonal-bipyramidal geometries with all nitrogen atoms the ligand coordinated to Co(II) center, contrast common six-coordinate pentadentate polypyridine ligands, where a monodentate solvent completes...
The solubility and phase behavior of linear polymethacrylate polymers, primarily poly(phenylalkyl methacrylate)s, in imidazolium-based ionic liquids (ILs) were systematically studied by changing the structure each component. Solutions polymethacrylates 1-alkyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide ([C(n)mim] [NTf2]) showed lower critical solution temperature (LCST) behavior, separation (T(c)) could be varied selecting an appropriate combination a polymer IL. An increase...
A simple, mild and inexpensive catalytic system, DBU benzyl bromide, was developed for the cycloaddition of epoxides to ambient CO<sub>2</sub> under metal-free solvent-free conditions a wide range converted corresponding cyclic carbonates with good excellent yields (81–95%).
The systematic investigation of supramolecular host systems consisting a primary amine/carboxylic acids has been performed upon changing the molecular length component. combinations enantiopure erythro-2-amino-1,2-diphenylethanol (1) and achiral benzoic acid derivatives (2a−e) were found to be effective for inclusion 1-phenylethanol (3a−d) with chiral recognition. X-ray crystallographic analyses revealed that one-dimensional (1D) helical columnar architecture was commonly constructed in...
Abstract The lower critical solution temperature (LCST) phase behavior of poly(benzyl methacrylate) (PBnMA) in room-temperature ionic liquids (ILs) was studied by considering the effect chemical structure ILs on separation ( T c ). It found that LCST PBnMA observed containing [NTf 2 ] anions and PF 6 anions. changed significantly with a small change structures cations. High-sensitivity differential scanning calorimetry (DSC) successfully performed for studying two different imidazolium-based...
4-Phenylazophenyl methacrylate (AzoMA) and benzyl (BnMA) were copolymerized to produce multistimuli-responsive polymers (P(AzoMA-r-BnMA)s) in a hydrophobic ionic liquid (IL), 1-ethyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide ([C2mim][NTf2]), as the solvent. P(AzoMA-r-BnMA)s with maximum of ca. 4 mol % AzoMA soluble [C2mim][NTf2] at low temperatures, they underwent lower critical solution temperature (LCST) phase separation an increase temperature. Under UV visible light...
In this study, 13 different chiral 1,3-diamines were synthesized from (-)-cis-2-benzamidocyclohexanecarboxylic acid. They successfully applied as ligands in the Cu-catalyzed asymmetric Henry reaction between benzaldehyde and nitromethane. It was confirmed that enantioselectivity of product could be controlled by substituents on two amino groups. A time-course study revealed a decrease caused spontaneous retro-Henry reaction, which suppressed conducting at 0 °C. This versatile afforded...
An efficient, metal-free catalytic system for the conversion of CO2 and epoxides to cyclic carbonates under mild conditions with good-to-excellent yields (57-99%) was developed. A possible reaction mechanism involving electrophilic activation by benzyl cations nucleophilic DMF is proposed.
Toward renewable energy for global leveling, compounds that can store ammonia (NH3), a carbon-free carrier of hydrogen, will be great value. Here, we report an organic–inorganic halide perovskite compound chemically NH3 through dynamic structural transformation. Upon uptake, chemical structure change occurs from one-dimensional columnar to two-dimensional layered by addition reaction. uptake is estimated 10.2 mmol g–1 at 1 bar and 25 °C. In addition, extraction performed condensation...
We report Cd nuclear magnetic resonance (NMR) and Re quadrupole (NQR) studies on Cd(2)Re(2)O(7), the first superconductor among pyrochlore oxides (T(c) approximately 1 K). The NQR spectrum at zero field below 100 K rules out any or charge order. spin-lattice relaxation rate T(c) exhibits a pronounced coherence peak follows weak-coupling BCS theory with nearly isotropic energy gap. results of NMR point to moderate ferromagnetic enhancement high temperatures followed by rapid decrease density...
The inclusion and chiral recognition of racemic arylalkanols by supramolecular helical architectures consisting enantiopure primary amines achiral carboxylic acids were thoroughly studied. Among the examined, a architecture composed salt erythro-2-amino-1,2-diphenylethanol (1 b) benzoic acid (2 a) was found to include wide variety with their chirality. gave dissymmetric 1D groove in crystal, enantioselectively included groove. size shape tunable proper selection component. origin combination...
The aggregation behavior of diblock copolymers with lower critical micellization temperatures (LCMT) in an ionic liquid (IL) is presented for the first time. Poly(methyl methacrylate) (PMMA), poly(benzyl (PBnMA), and polystyrene (PSt) are known to be soluble, low-temperature-soluble high-temperature-insoluble, insoluble, respectively, a typical hydrophobic IL, 1-ethyl-3-methylimidazoliumbis(trifluoromethane sulfonyl)imide. Well-defined thermosensitive copolymers, consisting PMMA as segment...
The antiperovskite compound ${\text{Mn}}_{3}{\text{Cu}}_{1\ensuremath{-}x}{\text{Ge}}_{x}\text{N}$ with $x\ensuremath{\sim}0.5$ has a giant negative thermal expansion coefficient due to the magnetovolume effect near room temperature. Competition between ${\ensuremath{\Gamma}}^{5g}$ and ${\ensuremath{\Gamma}}^{4g}$ antiferromagnetic structures around magnetic ordering temperature could be driving force for such phenomenon. In order examine this possibility, we performed neutron-diffraction...
Twenty chiral 1,3-amino sulfonamides of two classes (2a-i and 3a-k) have been prepared from (-)-cis-2-benzamidocyclohexanecarboxylic acid (1) studied as ligands for catalytic enantioselective addition Et(2)Zn to a variety aromatic aliphatic aldehydes. The 2 3 are regioisomers in which the position amine sulfonamide groups is exchanged. Each class with same chirality was shown afford sec-alcohols opposite stereochemistry. Structural surveys revealed that combination tertiary amino...