Total and double differential cross sections of ion-pair formation in collisions of K atoms with SnCl/sub 4/ and CCl/sub 4/

Journal Article · Tue Feb 15 04:00:00 UTC 1983 · J. Chem. Phys.; (United States)

OSTI ID:6369469

Lacmann, K; Maneira, M J.P.; Moutinho, A M.C.; Weigmann, U

The reaction K+ACl/sub 4/..-->..K/sup +/+(A-Cl/sub 4/)/sup -/* with A = Sn and C was examined as a function of the collision energy from threshold up to about 40 eV in the c.m. system. Total cross sections of the mass-selected negative ions and doubly differential cross sections (energy and angle) of the K/sup +/ ions have been determined. Electron affinities, bond energies, and electronic excitation were calculated from the appearance potentials. In addition, the total cross sections for SnCl/sub 4/ were measured and are contrasted with the earlier results of CCl/sub 4/ from Dispert and Lacmann. Although both parent molecules have the same electron affinity within their error limits (2.2 eV for SnCl/sub 4/ and 2.0 eV for CCl/sub 4/) and the same dissociation energy for the negative ions of 1.4 +- 0.2 eV, the product ion yields differ drastically. The main negative ion yield in K+SnCl/sub 4/ results from SnCl/sup -//sub 4/ formation (over 80%). Its lowest dissociation channel leads to SnCl/sup -//sub 3/ formation, while Cl/sup -/ ions are the main ions produced (90%) from CCl/sub 4/, with only 7% leading to CCl/sup -//sub 3/+Cl formation at higher energies. These results support orbital energy considerations of electron addition to SnCl/sub 4/ and CCl/sub 4/ as applied to the results of reactive collisions of these molecules. The electron affinity and an electronically excited state of SnCl/sub 3/ have been also determined. Morse potentials of CCl/sup -//sub 4/ and SnCl/sup -//sub 4/ were fitted to the experimental results of energy loss measurements from this work. The vertical electron affinities thus derived are 1.15 eV for SnCl/sub 4/ and -1.0 eV for CCl/sub 4/.

• Research Organization: Hahn-Meitner-Institut fuer Kernforschung Berlin GmbH, Bereich Strahlenchemie, Postbox, D 1000 Berlin 39, Federal Republic of Germany
• OSTI ID: 6369469
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 78:4; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
AFFINITY
ALKALI METALS
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
CARBON TETRACHLORIDE
CHLORIDES
CHLORINATED ALIPHATIC HYDROCARBONS
CHLORINE COMPOUNDS
COLLISIONS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
ELECTRONEGATIVITY
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
ION PAIRS
IONIZATION
METALS
MOLECULE COLLISIONS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
POTASSIUM
TIN CHLORIDES
TIN COMPOUNDS
TIN HALIDES
TOTAL CROSS SECTIONS