We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
General relationships between the kinetic characteristics of bulk and geminate recombination of radicals in solutions.
- Authors
Doktorov, Alexander B.; Lukzen, Nikita N.
- Abstract
Based on the (differential) Encounter theory developed in the literature, which describes the change in the internal quantum states of particles encountered in liquid dilute solutions due to stochastic (diffusion) molecular motion, closed kinetic equations for the temporal change in the concentration of free radicals recombining at encounters were obtained. The recombination rates from singlet and triplet states are often different, the recombination products from these states may also be different, i.e., the recombination process is spin-selective. The radical spins experience any quantum spin interactions including Zeeman interaction with external magnetic fields and hyperfine couplings with magnetic nuclei and the processes of longitudinal and transverse spin relaxation. In general, recombination can occur both from singlet and triplet states. The rates of such recombination are not limited by the traditional contact model, implying that recombination occurs only at the radicals contact, and, like any spin interactions, are not assumed to be spherically symmetric. Under these general conditions, an unambiguous relationship has been established between the bulk recombination rate constant and the recombination yields of the corresponding geminate reaction from the singlet and triplet states. In the particular case of the same spatial dependence of the rates of singlet and triplet recombination, the rate constant can be expressed only through the singlet recombination yield for a singlet precursor or through the triplet recombination yield for a triplet precursor, despite the fact that recombination occurs from both spin states. The particular case of spherically symmetric recombination probability of the freely diffusing radical pairs in liquid solution, which is the most common one in the literature, is also considered.
- Subjects
RADICALS (Chemistry); HYPERFINE interactions; HYPERFINE coupling; FREE radicals; QUANTUM states; PHOSPHORESCENCE spectroscopy; MAGNETIC fields
- Publication
Journal of Mathematical Chemistry, 2024, Vol 62, Issue 2, p502
- ISSN
0259-9791
- Publication type
Article
- DOI
10.1007/s10910-023-01550-z