Dark Structures in Molecular Radiationless Transitions Determined by Ultrafast Diffraction
- 28 January 2005
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 307 (5709), 558-563
- https://doi.org/10.1126/science.1107291
Abstract
The intermediate structures formed through radiationless transitions are termed “dark” because their existence is inferred indirectly from radiative transitions. We used ultrafast electron diffraction to directly determine these transient structures on both ground-state and excited-state potential energy surfaces of several aromatic molecules. The resolution in space and time (0.01 angstrom and 1 picosecond) enables differentiation between competing nonradiative pathways of bond breaking, vibronic coupling, and spin transition. For the systems reported here, the results reveal unexpected dynamical behavior. The observed ring opening of the structure depends on molecular substituents. This, together with the parallel bifurcation into physical and chemical channels, redefines structural dynamics of the energy landscape in radiationless processes.Keywords
This publication has 34 references indexed in Scilit:
- Ultrafast Diffraction of Transient Molecular Structures in Radiationless TransitionsThe Journal of Physical Chemistry A, 2001
- Femtosecond Dynamics of Pyridine in the Condensed Phase: Valence Isomerization by Conical IntersectionsThe Journal of Physical Chemistry A, 1999
- Vapor-Phase Photochemistry of DimethylpyridinesJournal of the American Chemical Society, 1999
- Dewar pyridine studied by matrix isolation infrared spectroscopy and DFT calculationJournal of Photochemistry and Photobiology A: Chemistry, 1999
- Laser Ionization Measurements of the Photodissociation Kinetics of Jet-Cooled BenzaldehydeThe Journal of Physical Chemistry A, 1997
- Photophysics of Gaseous Aromatic Molecules: Excess Vibrational Energy Dependence of Radiationless ProcessesPublished by Wiley ,1997
- Matrix-controlled photochemistry of benzene and pyridineThe Journal of Physical Chemistry, 1991
- Single-vibronic-level and excitation-energy dependence of radiative and nonradiative transitions in jet-cooled S1 pyridineThe Journal of Physical Chemistry, 1988
- Intramolecular electronic relaxation and photoisomerization processes in the isolated azabenzene molecules pyridine, pyrazine and pyrimidineFaraday Discussions of the Chemical Society, 1983
- Photochemistry of benzaldehydeJournal of the American Chemical Society, 1973