Interpretation of level-anticrossing phenomena in phosphorescence and optical nuclear polarization in organic crystals
- 10 August 1982
- journal article
- research article
- Published by Taylor & Francis in Molecular Physics
- Vol. 46 (5) , 917-939
- https://doi.org/10.1080/00268978200101681
Abstract
Level-anticrossing (LAC) phenomena in electronic states of molecules in organic crystals are described with a density matrix formalism. A condition for the observability of LAC signals in phosphorescence and ONP is derived. The validity of these predictions is tested at quadrupole satellite positions in the LAC spectra. As a consequence of the full density matrix treatment, off-diagonal damping terms Γ mn = T 2 -1(mn) are introduced. These turned out to be essential for the interpretation of the vanishing of experimentally observed LAC signals at higher order satellite positions. If T 2 equals the lifetime τ of the triplet state, earlier predictions based on kinetic arguments evolve as a limiting case of the present theory. The quadrupole satellite signals can be described properly by the density matrix formalism and there is no need for the introduction of an additional cross-relaxation mechanism.Keywords
This publication has 27 references indexed in Scilit:
- Optical detection of nuclear spin polarization via cross relaxation in A p-dibromobenzene single crystalChemical Physics Letters, 1979
- Study of the residual linewidth of the level-anti-crossing signal in p-benzoquinoneChemical Physics, 1978
- Optically-detected radiofrequency studies of level anticrossings in phosphorescent crystalsChemical Physics Letters, 1977
- Level-anticrossing and cross-relaxation effects in oriented molecular triplet states. 3(n,π*) benzophenones in 4,4′-dibromodiphenyletherThe Journal of Chemical Physics, 1977
- Optical nuclear polarization as a consequence of the non-crossing rule (level-anti-crossing): II. The influence of electronic relaxationChemical Physics, 1977
- Optical nuclear polarization as a consequence of the non-crossing rule (level-anti-crossing): I. Analytical treatment of ONP in the level-crossing regionChemical Physics, 1977
- Optical nuclear polarization as a consequence of the non-crossing rule (Level-Anti-Crossing)Chemical Physics, 1977
- Level anticrossing and mixing effects in excited molecular triplet states. Direct observation by optical detection of magnetic resonanceChemical Physics Letters, 1975
- Level anticrossing and cross-relaxation in phosphorescent crystalsMolecular Physics, 1975
- Optical Nuclear Polarization by Selective Population of Nuclear SubstatesZeitschrift für Naturforschung A, 1971