Low-energy reactions of CF22+ dications with atoms and molecules

State-selective, energy- and angle-resolved collisional interactions of CF22+ dications with atomic and molecular gases are studied at low collision energies. Single-electron transfer measurements help resolve the prevailing ambiguity vis-a-vis the lowest ionization energy of CF2+, yielding a value of 20.55 ± 0.5 eV. Ground state (1Σg+)CF22+ captures an electron from Ar, D2, N2 and CF4 predominantly into the ground 6a1 orbital of CF2+ but in CF22+-O2 and H2O collisions, the dominant capture channel is the excited (4b2) orbital of CF2+. Data are qualitatively interpreted using 'reaction windows' calculated using the Landau-Zener and extended over-the-barrier models.