- Tytuł:
- Fluorescence Properties of An Electron Acceptor Substituted Bis-Pyrazolo-Pyridine Derivative: NO$\text{}_{2}$-DMPP
- Autorzy:
-
Rechthaler, K.
Schamschule, R.
Parusel, A. B. J.
Rotkiewicz, K.
Piorun, D.
Köhler, G. - Powiązania:
- https://bibliotekanauki.pl/articles/1995490.pdf
- Data publikacji:
- 1999-03
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
33.50.Dq
34.70.+e - Opis:
- The fluorescence properties of 3,5-dimethyl-1,7-diphenyl-4 -(4'-nitro-phenyl)-bis-pyrazolo-[3,4-b;4',3'-e]-pyridine (NO$\text{}_{2}$-DMPP) and its parent compound 3,5-dimethyl-1,7-diphenyl-bis-pyrazolo-[3,4-b;4',3'-e]-pyridine (BPP, without the nitrophenyl substituent) were investigated. BPP is a highly fluorescent blue emitter and the fluorescence properties, the emission wavelength, and the fluorescence quantum yield, depend only slightly on solvent. On the contrary, acceptor substituted NO$\text{}_{2}$-DMPP shows dual fluorescence: A long-wavelength component experiences a red-shift with increasing solvent polarity but is efficiently quenched when the polarity exceeds that of solvents like 1,2-dichloroethane or 1-bromopropane. A weak short-wavelength component changes only slightly its position and intensity upon variation of the solvent but its yield increases strongly at low temperatures. The experimental results are discussed in the context of the results of semiempirical calculations which show that fluorescence originates from two closely lying fluorescent states which change their sequence and properties when the polarity of the solvent is varied. A twisted intramolecular charge transfer (TICT) state does most likely not contribute to the emission properties, because of its high energy.
- Źródło:
-
Acta Physica Polonica A; 1999, 95, 3; 321-334
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł