Dynamics of chemical and charge transfer reactions of molecular dications:beam scattering and total cross section data on CF2D+ (CF2H+), CF2+, and CF+ formations in CF22++D-2(H-2) collisions

Dynamics of formation of the chemical rearrangement product CF2D+, the char ge transfer product CF2+, and the dissociative products CF+ and CFD+ in col lisions of the molecular dication CF2+ + with D-2 was investigated in cross ed beam scattering experiments over the collision energy range 0.3-1.0 eV ( center of mass). The scattering data show that coulomb repulsion between tw o singly charged products, CF2+ + D+ and CF2+ + D-2(+), plays a dominant ro le in the nondissociative processes. A large fraction of the energy availab le (about 6 eV in the chemical reaction, about 4 eV in the charge transfer) goes into relative translational energy of the products. Relative total cr oss sections for formation of the nondissociative and dissociative products in collision of CF2+ + with D-2 and H-2 were determined over the collision energy range of 0.2-3.6 eV. The shape of the relative velocity dependence of the cross section for CF2+ formation can be described by a simple model based on the Landau-Zener formalism. The data suggest that the dissociative product CF+ is formed prevailingly in a subsequent dissociation of the cha rge transfer product CF2+. A potential surface model is described which acc ounts for competition of various processes in dication-neutral collisions. (C) 1999 Elsevier Science B.V.