Laser Photoionization TOF-MS Studies on Chemical Reactions of Laser Ablated Al Atom with Halomethanes

The gas-phase reactions between laser ablated Al atom and four different kinds of halomethane (CCl₄,CF₃Cl,CF₃Br,CF₄) are studied by laser photoionization time-of-flight mass spectrometer (TOF-MS) coupled with a pulse molecular beam device.The TOF mass spectra of neutral products show that AlCl or AlBr is produced more easily than AlF in the reaction of Al atom with CF₃Cl or CF₃Br,while AlF or AlCl is produced in the Al atom with CF₄ or CCl₄ reaction.Our results suggest that a Coulomb barrier in the exit channel has a governing role in the reactivity of aluminum with the halomethanes.