Temperature dependence of the triplet lifetimes of some aryl iodides and bromides

Journal Article · Mon Sep 01 04:00:00 EDT 1980 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.440406· OSTI ID:5068520

Grieser, F; Thomas, J K

A variable temperature pulse radiolysis study of the triplet state of iodonaphthalene and iodobiphenyl indicates that an intramolecular energy relocation process is inhibited as the temperature is lowered from 20 /sup 0/C, resulting in a lengthening of the lifetime of the triplet state. It is postulated that the triplet state energy of these aryl iodides is channeled into the C--I bond, causing bond dissociation. The activation energies for this process, in toluene, have been measured to be 5.9, 4.8, and 3.4 kcal/mole for 1-iodonaphthalene, 2-iodonaphthalene and 4-iodobiphenyl, respectively. Similar experiments with aryl bromides in toluene, at temperatures greater than 20 /sup 0/C, are also interpreted as indicating the dissociation of the C--Br bond from the triplet state. For 4-bromobiphenyl and 4,4'-dibromobiphenyl the activation energy is in the range of 10--13 kcal/mole. The results are discussed in relation to the work of Bersohn and co-workers.

• Research Organization: Chemistry Department and Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556
• OSTI ID: 5068520
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 73:5; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
AROMATICS
BROMIDES
BROMINE COMPOUNDS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
ENERGY LEVELS
EXCITED STATES
HALIDES
HALOGEN COMPOUNDS
IODIDES
IODINE COMPOUNDS
LIFETIME
LUMINESCENCE
MEDIUM TEMPERATURE
ORGANIC COMPOUNDS
PHOSPHORESCENCE
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIOLYSIS
TEMPERATURE DEPENDENCE