Photofragment ion imaging from mass-selected Mg+BrCH3 complex: Dissociation mechanism following photoinduced charge transfer

Abstract

We have observed fragment ion images produced by ultraviolet photodissociation of MgBrCH complex ions using a reflectron time-of-flight mass spectrometer combined with an imaging detector. The BrCH fragment ion was produced after the 266-nm excitation of MgBrCH. In the image of the BrCH ions, a split distribution was observed parallel to the polarization direction of the photolysis laser. In calculated potential energy curves, we found a repulsive potential correlated with a dissociation limit of Mg + BrCH: The calculation results indicate that the dissociation and the charge transfer occurred via non-adiabatic process after the 5A' ← 1A' photoexcitation. The obtained energy and angular distributions of BrCH photofragments were consistent with the fast BrCH formation process on the repulsive potential energy curve.

Cation−π Complexes of Silver Studied with Photodissociation and Velocity-Map Imaging

“…This SI-VMI instrument has similarities to other experiments described recently for photofragment imaging of mass-selected ions, − but it also has special features. The ions are not produced by photoionization, but instead grow directly in the laser vaporization process as they undergo cooling in a supersonic expansion.…”

Ion Imaging of MgI+ Photofragment in Ultraviolet Photodissociation of Mass-Selected Mg+ICH3 Complex

“…As mentioned above and in the previous reports, ,, pulsed high voltage (−2.0 kV, 0.6 μs width) was applied to the surface of the MCP detector. Therefore, an electrostatic field was created between the grounded surrounding flange parts and the MCP surface.…”

“…Details of the experimental setup were already described in the previous papers. ,, The present experimental apparatus consisted of a cluster ion source, a conventional angular-type reflectron TOF mass spectrometer (Jordan Co.) and a position-sensitive detector. The cluster ions consisting of Mg + and CH 3 I were produced by a pickup source .…”

“…The produced ions were detected by a linear time-of-flight (TOF) mass spectrometer, and both kinetic energy and angular distributions were measured simultaneously by a position-sensitive detector. Recently, ion imaging apparatuses were developed for observing the fragment ions produced from mass selected ions. − In our group, a reflectron TOF mass spectrometer combined with the position-sensitive detector for the photofragment ion imaging was used for the experiment. ,, …”

“…5−12 In our group, a reflectron TOF mass spectrometer combined with the position-sensitive detector for the photofragment ion imaging was used for the experiment. 8,9,11 Photodissociation reactions of metal−ligand complexes were studied in terms of a charge transfer process from metal to ligand molecules. 13 In the condensed phase, oxidation and reduction between organohalides (R−X) and organometallic catalysts are key reactions in the catalytic C−C bond formation.…”