Biphenyl fluorescence spectrum

Biphenyl, 45. 203. 348 absorption spectrum, 128 electron transfer, 465 fluorescence spectrum, 263 HOMO and LUMO energy, 128 methyl derivatives, 128 Biphenytene, 98 Btphenyiquinodimethane, 128 Biphenylyi /-butyl ketone. 383, 397... 

The efficiency of energy transfer from an excited biphenyl group to the naphthyl group was determined from the fluorescence spectrum and its plotted against the possible range of biphenyl-naphthyl distance in Figure 6. In the same figure, theoretical efficiencies, calculated from the Forster theory are also shown ... 

Steadily in the order 359, 385, 395, and 402 nm. The emission spectra exhibit a clearer vibrational fine structure than the absorption spectra. For spiro-sexiphe-nyl, 35b, a detailed analysis shows that the vibrational splitting of 0.20 eV corresponds to a phenyl breathing mode in the Raman spectrum [108]. If for spiro-sexiphenyl the outer biphenyl moieties are fixed parallel as in 4-Spiro (43), the absorption maximum is shifted from 346 to 353 nm (amorphous films) and the fluorescence maximum from 420 to 429 nm, maintaining the Stokes shift. The corresponding spectra are shown in Figure 3.17. The absorption signal at 310 nm in the spectrum of 43 can be attributed to the terminal fluorene moieties. The quantum yields for the fluorescence in the amorphous film are 38% for 35b and as high as 70 10% for 43 [89]. 

The laser-excited fluorescence from dibenzofuran in a biphenyl host at 4.2 K and three different sites in the lattice have been identified. The two-photon excitation spectrum of single crystals of carbazole at 4.2 K has been analysed in detail. Very extensive vibrationally unrelaxed fluorescence is observed following dye-laser excitation of single vibronic levels of naphthazanine and the rates and pathways of relaxation are examined by picosecond emission spectroscopy. The photophysics of rubrene peroxide have been measured for the first time by Bayrakceken. Picosecond fluorescence has been used to study the spectra and kinetics for Sj— So and Si transitions for... 

Soon after the report of de Vries and Wiersma" that at low temperature the coherence lifetime in Sj -So electronic transitions of organics could approach the fluorescence lifetime, Aartsma and Wiersma succeeded in detecting the first photon echo in an organic solid. The experiment was done at the S, <-S o transition of pyrene in biphenyl and is a beautiful illustration of the possible difference between optical T, and 7. In Fig. 13 we reproduce the absorption spectrum of pyrene in the origin region, which may be identified as a T -spectrum, and a photon-echo excitation spectrum, which may be called a 72-spectrum. The different lines in the... 

The chemiluminescence of these compounds was discovered [6] during an investigation into hindered rotation of the biphenyl sort. The parent compound [4] (n = 2) has a high quantum yield [10] (11 x 10" einstein M ), and the spectrum matches the fluorescence of 1,2-bis (isoquinolono) ethane (5) (n = 2)... 

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