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Photoluminescence of Acenaphthenone in Organic Solvents and Aqueoug Media
Author(s) -
Chou LiangChen,
Tzeng HueyFen,
Fang TaiShan
Publication year - 1992
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.199200025
Subject(s) - chemistry , phosphorescence , excited state , photoluminescence , photochemistry , quantum yield , protonation , fluorescence , solvation , quantum efficiency , solvent , aqueous solution , wavelength , benzene , luminescence , analytical chemistry (journal) , atomic physics , organic chemistry , optoelectronics , optics , ion , physics
The configuration of the lowest excited state of acenaphthenone, S 1 (π, π * ) or T 1 (π, π * ), depending on the solvent, dominates photoluminescence. The T 1 (n, π * ) state in aprotic organic solvents is responsible for the phosphorescence of acenaphthenone. The wavelengths of the phosphorescence measured in benzene are 576 nm and 635 nm (vibronic) with 3.3 × 10 −4 quantum efficiency. However, the S 1 (π, π * ) state in protic solution which dominates the fluorescence emission depending upon acidity is the most distinctive feature of acenaphthenone. The wavelengths of the emissions are 446 nm under water solvation with 0.185 quantum efficiency and 538 nm with 0.097 quantum efficiency under high acidity. The emission at 446 nm is assigned from a H‐bonded keto‐form excited state, whereas the emission at 538 nm is probably due to the excited state of protonated keto‐form. The pK a value in aqueous solution measured by diminution of fluorescence in basic solutions is 12.5 ± 0.4.