Radiation chemistry and mass spectrometry of trifluoromethyl iodide and pentafluoroethyl iodide in the gas phase. [. gamma. rays]
Ion-molecule reactions in CF/sub 3/I and C/sub 2/F/sub 5/I were investigated using a time-of-flight mass spectrometer and ion cyclotron resonance mass spectrometer. The most characteristic reaction is ion-molecule condensation leading to the formation of dimers such as (CF/sub 3/I)/sub 2//sup +/ in the CF/sub 3/I system and (C/sub 2/F/sub 5/I)/sub 2//sup +/ in the C/sub 2/F/sub 5/I system. Fluoride ion transfer processes are observed only when the final products are stable molecules. ..delta..H/sup 0//sub f/ for the parent molecule C/sub 2/F/sub 5/I is greater than or equal to -236.4 kcal/mole, the (CF/sub 3/CF/sub 2/-I) bond dissociation energy is less than or equal to 47.0 kcal/mole and the (CF/sub 3/-CF/sub 2/I) bond dissociation energy is less than or equal to 73. kcal/mole. The gamma-radiolysis of gaseous C/sub 2/F/sub 5/I was studied at 50 Torr and 24/sup 0/C, both pure and with added HI. For the pure system the major radiolytic products and their G values are I/sub 2/, 0.91; C/sub 2/F/sub 6/; 0.28; C/sub 2/F/sub 4/, 0.78; C/sub 3/F/sub 8/, 0.15; n-C/sub 4/F/sub 10/, 0.42; CF/sub 3/I, 0.18; CF/sub 2/I/sub 2/, 0.18; CF/sub 2/ICF/sub 2/I, 0.11; and CF/sub 3/CFI/sub 2/, 0.052. Addition of 5% HI increased the G values of I/sub 2/ (from 0.91 to 2.84) and the initial G value of CF/sub 3/I (from 0.18 to 2.50), while decreasing other product yields 50 to 100%. CF/sub 3/H, C/sub 2/F/sub 5/H, CF/sub 2/IH, and H/sub 2/ were also formed in the HI-added system. The low overall yield is due to back reactions between I/sub 2/ and C/sub 2/F/sub 5/ radicals. In the gamma-radiolysis of gaseous CF/sub 3/I, the major radiolytic products and G values in the pure system are I/sub 2/, 0.50; CF/sub 4/, 0.55; and C/sub 2/F/sub 6/, 0.11. With added HI scavenger, the additional products CF/sub 3/H, CF/sub 2/IH and H/sub 2/ were observed. (DLC)
- Research Organization:
- Florida Univ., Gainesville (USA)
- OSTI ID:
- 7223215
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
FLUORINATED ALIPHATIC HYDROCARBONS
RADIOLYSIS
IODINATED ALIPHATIC HYDROCARBONS
CHEMICAL BONDS
DISSOCIATION ENERGY
ELECTRON BEAMS
FORMATION HEAT
GAMMA RADIATION
HYDRIODIC ACID
ION CYCLOTRON RESONANCE SPECTROSCOPY
ION-MOLECULE COLLISIONS
MASS SPECTROSCOPY
RADICALS
SCAVENGING
TIME-OF-FLIGHT METHOD
BEAMS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COLLISIONS
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ENERGY
ENTHALPY
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
IODINE COMPOUNDS
ION COLLISIONS
ION SPECTROSCOPY
IONIZING RADIATIONS
LEPTON BEAMS
MOLECULE COLLISIONS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
PARTICLE BEAMS
PHYSICAL PROPERTIES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
REACTION HEAT
SPECTROSCOPY
THERMODYNAMIC PROPERTIES
400600* - Radiation Chemistry