Attachment of low-energy electrons (0-10 eV) to polyatomic molecules
Attachment of low-energy electrons (0-10 eV) to six normal perfluoroalkanes (n-C/sub N/F/sub 2N + 2/(N = 1-6)) three isomeric perfluoroalkanes (i-C/sub 4/F/sub 10/, i-C/sub 5/F/sub 12/, neo-C/sub 5/F/sub 12/), one cyclic perfluorocarbon (c-C/sub 5/F/sub 10/), four fluoroethers (CF/sub 3/OCF/sub 3/, CF/sub 3/OCF/sub 2/H, CF/sub 2/HOCF/sub 2/H, and CF/sub 3/OCH/sub 3/), two fluorosulphides (CF/sub 3/SCF/sub 3/ and CF/sub 3/SCH/sub 3/), and the freon CClF/sub 3/ has been studied using a time-of-flight mass spectrometer. The molecules n-C/sub n/F/sub 2N + 2/(N = 4-6), iC/sub 4/F/sub 10/, i-C/sub 5/F/sub 12/, neo-C/sub 5/F/sub 12/, and c-C/sub 5/F/sub 10/ were found to attach electrons dissociatively and/or nondissociatively. The autodetachment lifetimes, tau/sub a/, of a long-lived metastable parent and fragment anions of all these molecules were measured. Additionally, for those long-lived anions whose cross section was large, the variation of tau/sub a/ with incident electron energy was measured. On the other hand, for the lower normal perfluoroalkanes (N = 1-3), the fluoroethers, the fluorosulphides, and the CClF/sub 3/ molecules studied, only fragment negative ions were observed. The relative cross sections for all observed negative ions have been measured and corrected for the finite width of the electron pulse using an unfolding procedure. Possible fragmentation mechanisms of the dissociative negative ion states (NISs) leading to the production of the observed fragment anions have been suggested and discussed.
- Research Organization:
- Tennessee Univ., Knoxville (USA)
- OSTI ID:
- 5481166
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ELECTRON-MOLECULE COLLISIONS
ELECTRON CAPTURE
ORGANIC FLUORINE COMPOUNDS
ALKANES
CROSS SECTIONS
DISSOCIATION
ENERGY DEPENDENCE
EV RANGE 01-10
EXPERIMENTAL DATA
LIFETIME
TIME-OF-FLIGHT METHOD
CAPTURE
COLLISIONS
DATA
ELECTRON COLLISIONS
ENERGY RANGE
EV RANGE
HYDROCARBONS
INFORMATION
MOLECULE COLLISIONS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena