Lowest Triplet State of Anthracene

Abstract

A study has been made of the electronic transitions between the lowest triplet state of anthracene and its ground state. Low-temperature spectroscopic study of the phosphorescence revealed a sharp emission band with a 0,0-frequency (T→S) at 14 927 cm—1 (EPA rigid glass solution at 77°K). A vibrational analysis in terms of known Raman frequencies indicates that the transition is of a u→g allowed type. The T←S absorption band was observed in anthracene with the 0,0-frequency at 14 850 cm—1 (solution at 293°K). The study of the phosphorescence spectra of seven different chlorinated anthracenes confirmed the assignment of the anthracene lowest triplet. This study re-establishes the earlier value obtained by Lewis and Kasha, and rejects the recent value deduced by Reid. A correlation of the above results for anthracene with calculations and observations on related polyacenes indicates that the lowest triplet of benzene is 3B1u (in D6h), and for naphthalene, anthracene, and naphthacene the lowest triplet is 3B2u (in D2h). The perturbing singlets which mix with these triplets are obtained from previously derived rules for spin-orbital coupling in molecules.

Room temperature triplet state spectroscopy of organic semiconductors

“…Only a long pass, dielectric filter was used to measure the phosphorescence, sorting out higher order features from excitation and anthracene fluorescence. The 0-0 transition of the phosphorescence with peak energy of 1.83 eV agrees well with earlier reports1740. For the phosphorescence, we find a triplet lifetime of 8 ms (cf.…”

Synthesis and Characterization of Ru(II) Complexes with π‐Expansive Imidazophen Ligands for the Photokilling of Human Melanoma Cells

“… . † E T values of benzene , fluorene, phenanthrene, naphthalene , pyrene and anthracene were obtained from the literature.…”

“…Another example is the slightly improved dark toxicity of 7 compared to 4, where the phototoxicity is slightly better for 4 than 7. . † E T values of benzene (36), fluorene, phenanthrene, naphthalene (37), pyrene (38) and anthracene (39) were obtained from the literature. Figure 6.…”

Efficient Synthesis of Anthraquinones from Diaryl Carboxylic Acids via Palladium(II)‐Catalyzed and Visible Light‐Mediated Transformations

“…Further screening studies revealed that the optimal result could be obtained at 90 °C, and the sensitizer is not actually required in this process. These observations suggest that the energy barrier between 3 O 2 and 1 O 2 (22.5 kcal/mol) is presumably fulfilled with the anthracene chromophore, which generates 1 O 2 via triplet sensitization and undergoes cycloaddition with anthracene. Indeed, the addition of methylene blue or tetraphenylporphyrin was less effective in the formation of anthraquinone presumably as a result of competitive decomposition.…”