A5079948910- Photochemistry and Electron Transfer Studies
- Advanced Chemical Physics Studies
- Ionic liquids properties and applications
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- Molecular Spectroscopy and Structure
- Spectroscopy and Quantum Chemical Studies
- Free Radicals and Antioxidants
- Chemical Reactions and Mechanisms
- Radical Photochemical Reactions
- Atmospheric chemistry and aerosols
- Photochromic and Fluorescence Chemistry
- Electrochemical Analysis and Applications
- Oxidative Organic Chemistry Reactions
- Organic Chemistry Cycloaddition Reactions
- Crystallography and molecular interactions
- Chemical and Physical Properties in Aqueous Solutions
- Luminescence Properties of Advanced Materials
- Light effects on plants
- Radiation Effects and Dosimetry
- Advanced Chemical Sensor Technologies
- Chemical Reaction Mechanisms
- bioluminescence and chemiluminescence research
- Synthesis and Catalytic Reactions
- Polymer Nanocomposite Synthesis and Irradiation
Tokyo University of Agriculture and Technology
2013-2025
Tokyo Institute of Technology
2008-2016
Hiroshima University
2005-2008
Infrared spectra of the water clusters have been measured in N2 + O2 matrix. The aggregation process matrix has monitored by annealing deposited samples up to 40 K and UV irradiation. monomer, dimer, cyclic trimer pentamer are found as For hexamer, several structures such chair, cage, prism, bag 1 and/or book likely exist. By irradiation, is predominantly formed from monomer dimer. On other hand, sample, hexamers formed. theoretical calculation for revealed that formation one hydrogen...
The OH stretching (nu(OH)) band of methanol observed in condensed phase has been analyzed terms hydrogen-bonding patterns. Quantum chemical calculations for clusters have revealed that broadening the nu(OH) envelope is reasonably reproduced by considering nearest and next-nearest neighbor interactions through hydrogen bonding. Because bond formed between donor (D) acceptor (A) cooperatively strengthened or weakened a newly at D A, we proposed following notation patterns monohydric alcohols:...
The matrix-isolation infrared spectrum of a thermally evaporated ionic liquid, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([Emim][OTf]), was measured by FTIR spectroscopy and analyzed with the aid DFT calculations. main chemical species in observed IR mainly identified as 1:1 cation−anion pair, which corresponds to second stable ion-pair structure bonded through five hydrogen bonds between three O atoms anion side four H cation.
Low-temperature infrared spectra of thermally evaporated ionic liquids, 1-ethyl- and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide bis(trifluoromethanesulfonyl)amide have been measured in a cryogenic Ne matrix. The experimental IR spectrum can be reproduced theoretically by not B3LYP/6-31G* but MP2/6-31G* calculation, which suggests that the vibrational analysis for liquids composed anion would more successfully performed using MP2 calculation. By comparison matrix-isolation...
Abstract Photodissociation of three oxime ester compounds was investigated using time-resolved electron paramagnetic resonance spectroscopy. Direct evidences for the appearance methyl and iminyl radicals were obtained, their reactivity toward acrylate monomer studied.
Abstract Rotational correlation time (τc) of nitroxide radical solute was determined in ionic liquids by utilizing CW EPR spectroscopy. The experimental values τc viscous disagree with the calculated according to Stokes–Einstein–Debye (SED) equation. A fractional SED law examined for these solute–solvent combinations.
Several protic ionic liquids (PILs) with a wide range of pKa differences (ΔpKa) between the parent acid and base molecules were thermally evaporated in vacuum, trapped on CsI plate by cryogenic neon matrix-isolation method, studied Fourier transform infrared spectroscopy density functional theory calculations. The neutral proton-transferred cation–anion pair species identified as chemical components from PILs lower higher ΔpKa values, respectively. ΔpKa-dependent vaporization mechanism is...
Upon UV excitation, <italic>meta</italic>- and <italic>ortho</italic>-hydroxy methylcinnamate (<italic>m</italic>-, <italic>o</italic>-HMC) isomerize <italic>via</italic> a [<italic>trans</italic>-<sup>1</sup>ππ* → TS <italic>cis</italic>-S<sub>0</sub>] route, while <italic>para</italic>-HMC (<italic>p</italic>-HMC) isomerizes <sup>1</sup>nπ* T<sub>1</sub>(<sup>3</sup>ππ*) route.
The electronic states and photochemistry including nonradiative decay (NRD) trans(E) → cis(Z) isomerization of methylcinnamate (MC) its hydrogen-bonded complex with methanol have been investigated under jet-cooled conditions. S1(1nπ*) S2(1ππ*) are directly observed in MC. This is the first direct observation cinnamate derivatives. Surprisingly, order energies between nπ* ππ* opposite to substituted cinnamates. TD-DFT SAC-CI calculations support result show that substitution benzene ring...
Abstract We synthesized a new room temperature ionic liquid, [2PA-Hmim][Pf2N], and characterized the photochromic behavior by absorption spectroscopy. [2PA-Hmim][Pf2N] was found to be liquid where solvent itself undergoes reaction.
Rotational motion of a nitroxide radical, peroxylamine disulfonate (PADS), dissolved in room temperature ionic liquids (RTILs) was studied by analyzing electron paramagnetic resonance spectra PADS various RTILs. We determined physical properties such as the hyperfine coupling constant (A), dependence anisotropic rotational correlation times (τ(∥) and τ(⊥)), anisotropy (N). observed that A values remain unchanged for RTILs, which indicates negligible interaction between N-O group cation RTIL....
The charge-transfer (CT) absorption bands of ion pairs composed 1-ethylpyridinium (Epy(+)) and halogen anions (X(-): Cl, Br, or I) were measured in dichloromethane solutions EpyX. CT band the Epy(+)I(-) pair shows clear splitting because spin-orbit interaction excited state. transition energy an Epy(+)X(-) a solution is related to electron affinity X, which accordance with Mulliken theory for bands. Extinction coefficients determined using absorbance, ion-pair concentration was estimated on...
The photoreaction of 2-amino-5-methylpyridine was investigated by matrix-isolation infrared spectroscopy and DFT calculation. Photoinduced reversible amino (NC−NH2)−imino (NH−CNH) tautomerism found between 5-methyl-2(1H)-pyridinimine; the tautomer changes to imino UV irradiation (340 > λ ≥ 300 nm) reverse change occurs longer-wavelength light (420 340 nm). results CASSCF calculation revealed that amino−imino proceeds in vibrational relaxation process from electronic excited state ground...
Abstract The FTIR spectrum of vaporized ionic liquid has been measured with a low-temperature rare-gas matrix-isolation technique for the first time. 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, EmimTFSI, was employed as thermally vaporizable liquid. matrix-isolated IR found to be different from either neat or theoretically simulated stable 1:1 ion-pair spectrum. This observation may suggest that certain structure phase expected form.
Dynamic electron polarisation (DEP) produced by the quenching of dye molecules in triplet excited states nitroxide radicals was investigated aqueous solutions pulsed paramagnetic resonance and transient absorption spectroscopy. An analysis measured rate constants suggests that is promoted either exchange or charge-transfer mechanisms for a doublet radical pair. unusually large DEP on found generated Eosin Y Rose Bengal systems solutions. Quantitative indicates values range from −40 to −150...
Torsional isomerization of tetrachlorohydroquinone in a low-temperature argon matrix has been investigated by Fourier transform infrared spectroscopy with the aid density-functional-theory calculations. Infrared bands more stable isomer, trans, were observed an at 16 K. Those less cis, during UV irradiation but disappeared immediately after was discontinued. The from trans to cis occurred dark despite high torsional barrier, 19.1 kJ mol-1, when temperature increased 30 enthalpy difference...