Photophysics and photochemistry of monothioanthraquinone
The green 10-thioxo-9(10H)-anthracenone, also known as monothioanthraquinone, exhibits striking spectral differences from that of the pale yellow anthraquinone. An n ..-->.. ..pi..* transition exists at 695 nm. No fluorescence is observed, but strong phosphorescence is detected with an emission maximum around 950 nm indicating efficient S/sub 1/ ..-->.. T/sub 1/ crossing. Theoretical calculations employing INDO, CNDO, and PPP methods on the singlet- and triplet-state energy levels are in excellent agreement with the experimentally observed ones. An experimental value of approx. 700 cm/sup -1/ was obtained for the lowest singlet-lowest triplet splitting. Laser flash photolysis in benzene produced a triplet transient with the difference absorption spectrum having maxima at 440 and 600 nm. The lifetime of the triplet transient is approx. 100 ns. The triplet transient is capable of hydrogen abstraction, thus supporting the theoretical calculations which show the lowest triplet state to be of n,..pi..* nature.
- Research Organization:
- Univ. of Houston, TX (USA)
- OSTI ID:
- 5352962
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 91:27; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400500* -- Photochemistry
ABSORPTION SPECTROSCOPY
ANTHRAQUINONES
AROMATICS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DE-EXCITATION
DECOMPOSITION
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
EXPERIMENTAL DATA
INFORMATION
LASERS
NEODYMIUM LASERS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PHOTOLYSIS
QUINONES
RADIATIONLESS DECAY
SOLID STATE LASERS
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
THEORETICAL DATA
THIOLS