Molecular Photophysics of Acridine Yellow Studied by Phosphorescence and Delayed Fluorescence: An Undergraduate Physical Chemistry Experiment

Role of Boron in the Polymer Chemistry and Photophysical Properties of Difluoroboron−Dibenzoylmethane Polylactide

“…It was assumed that stronger F−F interactions significantly reduce the energies of singlet excited states for polymers with much higher dye loadings such as B1 . Thus, the maxima for fluorescence (499 nm) and delayed spectra (522 nm) are very close for B1 (23 nm, similar effects are also seen in acridine yellow in trehalose glass) but are quite different for B2 (440 and 507 nm, 67 nm difference). Delayed emission lifetimes (Table ) also support this assumption since B2 has a substantially longer lived emission (426 ms) compared to B1 (125 ms) perhaps due to a much larger singlet−triplet (ST) energy splitting and a smaller probability of thermal repopulation of the short-lived singlet excited state from the triplet state.…”

Organic Photocatalysts for the Oxidation of Pollutants and Model Compounds

“…The characteristic singlet excited-state properties of photocatalysts are listed in Table , ,,,,,− including the emission wavelength (λ em ), singlet state energy ( E S ), fluorescence quantum yield (Φ F ), and lifetime of the singlet excited state (τ S ). When different values are reported (due, for instance, to the use of different solvents or experimental conditions), several data points are included.…”

A Mechanistic Study of Terbium Phosphorescence Quenching

“…Matko et al (16) concluded that "the quenching was practically independent of temperature" in the range between 6 °C and 42 °C for this system. Thorough study suggests that the slight temperature dependence observed in Figure 3 is typical and reproducible Time / (10 for this temperature region. During the first student trial of this experiment, this gradual increase was enough to make most of the students conclude that collisional quenching was being observed.…”

“…The lifetimes of the fluorophores used by Fraiji et al (9), while short, are typical of organic fluorophores. One can find phosphors with longer lifetimes, but most of these require cryogenic conditions or immobilization of the phosphor within a solid-phase sample matrix (10). Four of the rare earth metals (Sm, Eu, Tb, Dy), alone in ionic form or as part of inorganic compounds, are known to produce long luminescence lifetimes (some fluorescence, some phosphorescence; refs 11-13).…”