Search

Abstract: Ionic fragmentation following the inner-shell photoexcitation of [(CH3)2CO]Ar n heteroclusters was investigated in the Ar L23- and O K-edge regions. A partial ion yield (PIY) measurement revealed that and various acetone fragments (, , , , and ) were produced following the Ar L23-shell excitation. In the O K-edge region, the PIY of O+ exhibited a sharp resonance peak at the O 1s→π∗(Cnce excitation. The selective O+ formation was interpreted as the suppression of statistical fragmentation, which was dominant in isolated acetone, owing to the dissipation of excess energy into Ar clusters. [Copyright &y& Elsevier]

Abstract: Time-of-flight mass spectra have been measured for inner-shell ionization of ethanol molecules, its clusters, and methanol clusters at the oxygen K-edge regions. Only in the case of the ethanol clusters, a fairly intense signal corresponding to H3O+ has been observed. The measurements for ethanol-d 1 (C2H5OD) suggest that at least one H atom in the H3O+ ion originates from the C2H5 group of neighbouring ethanol. It is proposed that in addition to the O–H⋯OH type hydrogen bonding in the ethanol clusters, the H in the C2H5 group and OH interact with each other. [Copyright &y& Elsevier]

Total photoabsorption cross-sections of trifluoromethyl sulfur pentafluoride, CF3SF5, were measured in the C, F and S K-shell regions by using a double ionization chamber and synchrotron radiation at the SPring-8 facility. The maximum cross sections were found to be 6.3, 5.0 and 1.1 Mb for the C, F and S K-edges, respectively. The spectral features in the F K-shell region were characterized by the photoabsorption spectra of CF4 and SF6 and those in the S K-shell region resemble the peaks of SF6. The observed peaks for CF3SF5 were tentatively assigned on the basis of a comparison with those for CF4 and SF6 measured simultaneously for references. [Copyright &y& Elsevier]