Exciton percolation in mixed molecular crystals and aggregates: from naphthalene to photosynthesis

Abstract

Did you calculate the magnitude of this splitting or was it found from the experiment? F. Adar. You know that the splitting is possible because the crystal field has lower symmetry than that of free space. You know that the 5d orbitals split into two levels with twoand threefold degeneracies. Then you can calculate which set is low in energy. G. W. Canters. But you mentioned that the splitting would be large. What do you mean by large? F. Adar. Large enough to observe a diamagnetic species. E. R. BERNSTEIN. Do you have any other information besides'line width on the lifetimes of the states you observe? F. Adar. We ran the absorption spectra at liquid nitrogen temperature from which we estimated the line widths. We found that the emission was consistent with quantum yields that" the line widths would predict.

Dynamics of energy transport in ternary molecular solids. I. Naphthalene steady state fluorescence

“…This is consistent with our result [I 2 10') if we assume that in the pure crystal the major contribution to the homogeneous linewidth is due to exciton-phonon scattering (see reservation above and in Francis and Kopelman [32]). Furthermore, we assumed that this phonon scattering is the same for pure CloHs and mixed Cu&,/CloHs/BMN crystals, as the phonons of all three components are al?irrlgumared [45,65]. This was the justification for our tentative conclusion that the 1 values_shauId be constant throughout our concentration range and aPPlicable to the pure naphthalene crystal.…”

“…We believe that "correlated hopping" can describe the situation between the !i.mit of "incoherence" (hopping model) and the limit of "coherence" (band model). While in small clusters (dimers) it is easy to talk about "coherence", the situation in a pure crystal may be different [65]. We believe that the model of "correlated hopping" can 5e applied to both "neat" crystals (at finite temperatures) and to mixed crystals (high C,).…”

“…The phonons of CroHB and CioDB are in the amalgamation limit [AS] throughout the whole concentration range, as has been amply demonstrared from Raman and farinfrared studies [66]. The minute xnounts of BktN in out sample do not change this situation because: (1) BMN and naphthalene are also [65] in the amalgamation limit.…”

Multifunctional nanoplatforms for fluorescence imaging and photodynamic therapy developed by post-loading photosensitizer and fluorophore to polyacrylamide nanoparticles

“…In nanoconstructs 7 and 8 in which the PS and CD were post-loaded in a ratio of 2 to 1 and 4 to 1 on excitation of the cyanine dye at 782 nm gave fluorescence at 866 and 870 nm respectively. Interestingly, both nanoconstructs on in vivo excitation at 665 nm produced a significant fluorescence beyond 860 nm, which can be explained by the phenomenon known as the Förster (Fluorescence) Resonance Energy Transfer (FRET), or by the more general phenomena of energy migration, or excitation percolation, followed by energy trapping 28,29 , analogous to the energy transport and funneling process in photosynthetic antenna. On the basis of imaging results summarized in Figure 4, the nanoconstruct 7 provided the greatest contrast between the tumor and non-tumor tissues.…”

Potential for Heightened Sulfur-Metabolic Capacity in Coastal Subtropical Microalgae

“…For example, we detected methyl-sulfanyl naphthalene at high levels in the Halamphora species. Naphthalenes have been previously shown to undergo oxidation in many photosynthetic organisms (Fassioli et al., 2014), and their photochemistry closely mimics that of chlorophyll molecules (Kopelman, 1976). The knowledge regarding the range of occurrences among different clades is sparse (Ibrahim and Mohamed, 2016); however, among the species that we examined, we observed naphthalene carboxamide in Navicula sp .…”