Results 161 to 170 of about 28,761 (191)
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Quantum beats on intersystem crossing
Journal of Molecular Structure, 1980Abstract Quantum interference effects in the S 1 → T intersystem crossing and T → S 0 phosphorescence of aza-aromatic molecules are demonstrated. These may arise if the electronic structure of the triplet state T is such that the principal spin-orbit coupling path connects a non-stationary spin state of T with the singlet system.
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Hyperfine Interaction Promoted Intersystem Crossing
Applied Magnetic Resonance, 2019The mechanism of the intersystem crossing (ISC) in planar aromatic hydrocarbons is revised by considering hyperfine interaction promoted singlet–triplet transitions. The density matrix of the spin system of the metastable triplet state is derived. Extra terms including the electron-nuclear ordering, the ordering between the magnetic nuclei of the ...
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Intersystem Crossing Processes in Nonplanar Aromatic Heterocyclic Molecules
The Journal of Physical Chemistry A, 2007A comprehensive study of the photophysical properties of a series of monoaza[5]helicenes is presented on the basis of joint optical spectroscopy and quantum chemistry investigations. The molecules have been characterized by absorption and CW/time-resolved luminescence measurements.
Schmidt, K +10 more
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Intersystem Crossing in Complex Molecules
1980The general question of singlet-triplet intersystem crossing is addressed in the context of large organic molecules, i.e., “complex” molecules capable of self-relaxation in the absence of collisions. Examples of spectral properties of such molecules in the vapor phase are discussed, relying on extensive Russian literature in this area.
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Intersystem crossing in photosynthetic pigments
Chemical Physics Letters, 1977Abstract Intersystem crossing (ISC) of chlorophyll a in solution exhibits a strong solvent dependence and a weak deuterium isotope effect. This is due to the importance of the molecular geometry in promoting ISC. These results are generalized to other closely related photosynthetic pigments.
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Anti‐Stokes Emission Utilizing Reverse Intersystem Crossing
Angewandte ChemieAbstractPhoton‐upconversion (PUC) processes in organic molecular systems, such as triplet‐triplet upconversion and hot‐band absorption, are promising technologies for future energy harvesting. Although these processes can generate high‐energy excitons compared to excitation energy, a PUC process with a high yield and no energy loss has not been ...
Shintaro Kohata +5 more
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Intersystem crossing at singlet conical intersections
Journal of Photochemistry and Photobiology A: Chemistry, 2007Abstract The energy of the lowest triplet state of organic molecules is intermediate between the ground state and the first excited singlet. At the S 1 / S 0 conical intersection, the two singlet states are degenerate. It is shown that for some molecules (ethylene, benzene, toluene and pyrrole) the T 1 state is also degenerate with the two ...
Semyon Cogan +2 more
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Excited triplet — singlet intersystem crossing
Chemical Physics Letters, 1969Abstract The quantum yield for intersystem crossing from excited triplet states into the singlet manifold was estimated for several molecules by observing the fluorescence emission from the lowest excited singlet state which resuleted from photo-excitation of metastable triplet states. In all cases these quantum yields were very small.
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Intersystem Crossing and Multiple Tunnelling
physica status solidi (b), 1969AbstractThe problem of non‐adiabatic tunnelling in the system of two coupled parabolic terms interacting with the environment has been solved. The model is applied to intersystem crossing in the simple centre of luminescence. The role of multiple passage through the region of term interaction has been cleared up.
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Intersystem crossing in hexahelicene
Journal of the American Chemical Society, 1979S. S. Kim, S. I. Weissman
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