Absolute fluorescence quantum yields for vapour-phase benzene and naphthalene, and comments on the non-radiative processes
✍ Scribed by L.M. Hall; T.F. Hunter; M.G. Stock
- Publisher
- Elsevier Science
- Year
- 1976
- Tongue
- English
- Weight
- 570 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
Optx-:xoustic mcasurcments have been employed m the determination of absolute quantum ylclds for benzcnc and nnphth&nc. Heat yield5 XC mcnsurcd by a method using oxygen quenching of both triplet ar.d singlet states. For vlbmtionally rcla?rcd excited singlet states the fluorescence quantum yields, ~8, are 0.16 t 0.02 and 0.79 c 0.02 for benzene and naphthnlcnc respectively. For 0.07 torr naphthknc at room tcmpcr;lturc with 248 nm excitation, of = 0.35 * 0.03 nnd the qunntum yield of internal conversion is less than 0.05. The decay of the highly vibrational[y excited triplet state is dommatcd by vibrational relaxation for 0.07 torr naphthalenc.
but for bcnrcne, even at high pressures. strong competition comes from an indirect couplmg process to the ground state.