N-サリチリデンアニリンの高速ダイナミックス : 励起状態分子内プロトン移動反応と内部転換の競合

2003年分子構造総合討論会, 2003年9月24日-27日, 京都テルサ(京都), 4Ap0

N-サリチリデンアニリンのイオン検出フェムト秒時間分解分光 : フォトクロミック反応における高速内部転換の重要性

2004年分子構造総合討論会, 2004年9月27日-30日, 広島国際会議場(広島), 3D0

光によるコバルトカーボンクラスター化合物の液相合成とその構造と磁性の研究

2002年分子構造総合討論会, 2002年10月1日-10月4日, 神戸国際会議場(神戸), 2P05

ピコ秒・フェムト秒時間分解分光法によるジアリールエテン類のフォトクロミック反応ダイナミックスの研究

2002年分子構造総合討論会, 2002年10月1日-10月4日, 神戸国際会議場(神戸), 3A0

Electric Field Effects on Photoluminescence of CdSe Nanoparticles in a PMMA Film

External electric field effects on spectra and decay of photoluminescence (PL) as well as on absorption spectra were measured for CdSe nanoparticles in a poly(methyl methacrylate) (PMMA) film. Electrophotoluminescence (E-PL) spectra as well as electroabsorption spectra show a remarkable Stark shift which depends on the particle size, indicating a large electric dipole moment in the first exciton state. The E-PL spectra also show that PL of CdSe is quenched by application of electric fields, and the magnitude of the field-induced quenching becomes larger with increasing size. The PL decay profiles observed in the absence and presence of electric field show that the field-induced quenching of PL mainly originates from the field-induced decrease in population of the emitting state prepared through the relaxation from the photoexcited state

Electroabsorption spectra of PbSe nanocrystal quantum dots

The quantum-confined Stark effect of PbSe nanocrystal quantum dots (QDs) in a polymer film has been studied for the near-infrared absorption in the region of 1300-1600 nm (corresponding to diameters of 4.0-7.0 nm) by using electric field modulation spectroscopy. Electroabsorption spectra of QDs show the electric-field-induced energy shift in the exciton state, resulting in the spectral broadening given by the second derivative of the absorption spectra. It is shown that the magnitude of the change in electric dipole moment following excitation into the first exciton state increases with an increase in the size of QDs

External electric field effects on fluorescence of perylene doped in a polymer film

Fluorescence and electrofluorescence spectra of perylene molecules doped in a polymer film at different concentrations have been measured at different temperatures in the range of 70–295 K. At high concentrations where excimer is formed, LE fluorescence emitted from the locally excited state of perylene is quenched by an electric field at any temperature, indicating a field-induced enhancement of the excimer formation rate. Fluorescence of the Y-type excimer of perylene molecules shows a field-induced enhancement at room temperature, whereas it shows a field-induced quenching at low temperatures. The temperature dependence of the electric field effects on fluorescence has been discussed

pH Dependence of the Fluorescence Lifetime of FAD in Solution and in Cells

We have studied physiological parameters in a living cell using fluorescence lifetime imaging of endogenous chromophores. In this study, pH dependence of the fluorescence lifetime of flavin adenine dinucleotide (FAD), that is a significant cofactor exhibiting autofluorescence, has been investigated in buffer solution and in cells. The fluorescence lifetime of FAD remained unchanged with pH 5 to 9 in solution. However, the fluorescence lifetime in HeLa cells was found to decrease with increasing intracellular pH, suggesting that pH in a single cell can be estimated from the fluorescence lifetime imaging of FAD without adding exogenous fluorescent probes