Nozomu Ebara

Triplet dynamics of benzaldehyde as studied by electron impact excitation

Abstract Electron-impact-induced luminescence was measured for benzaldehyde at low vapor pressure. Phosphorescence bands from the zero-point level of T 1 were observed at 397.427, and 460 nm. The pressure dependence of the phosphorescence decay rate was found to be essentially the same as that obtained by optical excitation. In addition to these bands, closely spaced, weak emission bands were observed. These emissions were found to have much shorter lifetimes than the phosphorescence from the zero-point level and to be sensitive to collisional quenching. We assign the latter bands to the phosphorescence from vibrationally excited T 1 molecules.

Triplet-state dynamics at low pressures as studied by electron-impact-induced phosphorescence: Acetophenone

Abstract Electron-impact-induced phosphorescence was observed for acetophenone at pressures between 3.2 and 48 mTorr. In addition to normal phosphorescence from the T1 zero-point level, we observed phosphorescence from vibrationally excited T1 molecules at lower pressures. Collisional quenching of the triplet levels is discussed based on the pressure dependence of the phosphorescence. Excitation functions were measured for these two kinds of phosphorescence and the mechanism of triplet-state formation is discussed.

Electron-impact luminescence spectra and neutral fragments: Identification of neutral fragments by use of fragment emissions

Electron-impact luminescence spectra were measured for cyclohexanol, acetic acid, pyridine, pyrimidine, benzonitrile, aniline, nitrobenzene, p-methoxy-nitrobenzene, 1-chlorobutane, 1-chloropentane, tetrahydrofuran and anisole. The spectra were analyzed and compared with the literature data of mass spectrometry. It was found that fragment emissions of OH(A2Σ+-X2Π), CN(B2Σ-X2Σ), NO(B2Π-X2Π) and HCl+(A2Σ-X2Π) can be used for the identification of neutral fragments of OH and H2O, HCN, NO and HCl, respectively.

Electron-impact-induced luminescence and triplet-state dynamics of acetone and perdeuterated acetone at low pressures

Abstract Luminescence from acetone and acetone- d 6 has been investigated at pressures of 3.4–13 mTorr under electron impact. The decay curves of both compounds are found to be composed of two or three components depending on pressure. The decay rates and time-resolved spectra have been measured for the respective components as functions of pressure, and the nature of the states responsible for these emission components is discussed in relation to triplet-state dynamics.