Phosphorescence spectrum anthracene

Phosphorescence Spectra.—Luminescence from a low-lying triplet state of water368 has been reported. It has been shown that two long-lived emission systems in the biacetyl crystal described previously by Sidman and McClure (see ref. 368) are in fact due to impurities, and a complete analysis is presented of the true 3AU xAg phosphorescence. The zero-zero band in emission is found at 20 327 cm-1.135 A satisfactory account of the six characteristic bands in the phosphorescence spectrum of benzene has been given on the basis of pseudo-Jahn-Teller vibronic interactions between the lower 3Blu and 3Elu states in which two active vibrations in the pseudo-cylindrical approximation are considered.369 The phosphorescence spectra of anthracene,3700 coronene,8706 benzophenone in aqueous solution,371 pyrimidine derivatives,372 porphyrins,298 873 and crystalline charge-transfer complexes 374 have been reported. 

The lowest excited triplet state Ti of this crystal belongs, in contrast, only to the anthracene molecule and corresponds to triplet Frenkel excitons with no polar character, as we described in Sect. 6.5. This follows from the energetic position (not shown here) and the vibronic structure of the phosphorescence spectrum [36]. 

Figure 15.11 Absorption and emission spectra of anthracene. These are at room temperature, except for the phosphorescence that was measured at 77 K. The singlet-triplet absorption is the triplet excitation spectrum in single-crystal anthracene. The dotted lines are the simulated absorption ( s=26,400 cm, <7 =350 cm , 5a = 1-18, v =1450 cm ) and fluorescence ( s=26200 cm", ...

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