Coumarin 153 Dynamics in Ethylammonium Nitrate: The Effects of Dilution with Methanol

Magic angle intensity decay and dynamic fluorescence anisotropy measurements were made on the binary solvent system composed of ethylammonium nitrate ([N2,0,0,0+][NO3−], EAN) + methanol (MeOH) across the complete EAN mole fraction range (xIL = 0–1) using the neutral dipolar solute coumarin 153 (C153) at 295 K. Stokes–Einstein–Debye (SED) hydrodynamic theory was used as a model framework to assess the C153 rotational reorientation dynamics. Departure from stick SED prediction was observed (in contrast to literature reports that used cationic or anionic dyes) and indicated a significant influence of domain nanoheterogeneity on probe dynamics. Steady-state spectroscopy indicated minimal changes in spectral peak and width with mole fraction, except at xIL = 0.3 where absorption widths decreased by ~170 cm−1, signaling that C153 sensed a change in solution heterogeneity. Magic angle intensity decays corroborated the steady-state observation and the excited-state lifetimes showed a marked change from xIL = 0.2–0.4 where EAN-EAN interactions became notably more significant. C153 average rotation times (⟨τrot⟩) showed significant solvent decoupling with increased EAN. The rotational data were fit to a power law dependence, ⟨τrot⟩ ∝ (ηT)p, where p = 0.82, demonstrating the presence of dynamic heterogeneity in the EAN/MeOH solutions. With increased EAN, rotation times showed that the heterogeneity became increasingly more significant since the rotation times systematically decreased away from the hydrodynamic stick limit.

Materials for D-D-A ternary organic solar cells: an absorption model study

Heterojunction solar cells based on ternary blends of two donors (absorbers and one acceptor) were investigated using modeling. The Tauc-Lorentz model and experimental absorption spectra of selected compounds were used in the simulations. The optimization process was carried out in this way to maximize the absorption of the system. Poly(3-hexylthiophene-2,5-diyl) (PEHT) was investigated as a first donor, which was mixed respectively with poly(3-octylthiophene-2,5-diyl) (P3OT), coumarin 153, purpurin, fluorescent brightener 184, N-chloroethylene carbazole, and 1,3,6,8 tetrachloro 9n amylocarbazole. Simulations were also performed for the Tauc-Lorentz model.

Evaluating excited state atomic polarizabilities of chromophores

Ground and excited state atomic polarizabilities of the chromophoresN-methyl-6-oxyquinolinium betaine and coumarin 153 have been evaluatedviaquantum mechanics.

Efficient light harvesting within a C153@Zr-based MOF embedded in a polymeric film: spectral and dynamical characterization

Energy transfer within a hybrid C153@Zr-NDC composite material incorporated into PC films. M* and (E*) are the excited monomers and excimers of the MOF, respectively. C153 is Coumarin 153.