Spectroscopic Properties of 2,5,8,11-Tetra-tert-butylperylene in Polymer Films

Abstract

The spectroscopic properties of 2,5,8,11-tetra-tert-butylperylene in poly(vinyl alcohol) have been studied. To this end, the absorption and fluorescescence excitation and emission spectra have been measured. The shape of the spectra in poly(vinyl alcohol) is virtually identical with that in propanediol and lipid systems. The Förster radius calculated from the spectra was found to be 3.7 ± 0.3 nm. The natural fluorescence lifetime of 2,5,8,11-tetra-tert-butylperylene in poly(vinyl alcohol) was also calculated from the spectra and found to be 5.3 ± 0.2 ns. The fluorescence decay in poly(vinyl alcohol) exhibits monoexponential behavior with a lifetime of 4.5 ± 0.3 ns. It is shown that the fluorescence anisotropy of 2,5,8,11-tetra-tert-butylperylene in the polymer matrix does not decay, indicating that its motion is quenched on the time scale of the fluorescence decay. The initial value of the fluorescence anisotropy, r(0), for excitation at 260 nm and emission at 455 nm is −0.16 ± 0.02 while for excitation at 440 nm and emission at 455 nm it is 0.35 ± 0.02. The fluorescence transition dipole moments relative to the long molecular axis in the plane of the molecule were determined from angle-resolved fluorescence depolarization measurements. This yields an emission dipole moment at 459 nm of 5 ± 5°, an excitation dipole moment at 416 nm of −10 ± 5°, and an excitation dipole moment at 256 nm of 80 ± 5°.

Improved photon absorption in dye-functionalized silicon nanocrystals synthesizedviamicrowave-assisted hydrosilylation

“…Indeed, our examination of the PL lifetime of the dye (1) dissolved in hexane displays the lifetime of 3.2 ns, whereas the unsubstituted perylene or perylene with saturated alkyl substituents (for instance 2,5,8,11-tetra-tert-butylperylene) demonstrated usually longer lifetimes of 4.3-4.5 ns. 45,46 Nevertheless, this difference in τ 0 leads to a very minor correction of η DET = 99.3% (for τ 0 = 3.2 ns) instead of 99% if τ 0 = 4.4 ns. Thus, the highly efficient DET explains similar PLQY values obtained at 300 and 440 nm excitation.…”

Concentration-Dependent Fluorescence Color Tuning of the Difluoroboron Avobenzone Complex in Polymer Films

“…Fluorescent polymer films have been widely studied: not only synthesized dye-labeled polymers 1, 2 but also fluorescent dyes dispersed in conventional optical polymers such as poly(methyl methacrylate) (PMMA) [3][4][5][6][7] and poly(vinyl alcohol) (PVA). [8][9][10] Luminescent solar concentrators (LSCs) are one of the applications of fluorescent dye dispersed polymer films because they require a high fluorescence quantum yield to efficiently collect and transport sunlight.…”

Properties and evolution of emission in molecular aggregates of a perylene ammonium derivative in polymer matrices

“…3,4 To control these emissive properties, it is of crucial importance to obtain detailed information on the origin and evolution of the emission in the aggregated state where specific interactions can lead to the appearance of new colors. [5][6][7][8][9][10] Along these lines, we studied the fluorescent properties of aggregates in a poly(vinyl alcohol) (PVA) matrix. 11,12 The segregation of solute molecules in PVA films prepares aggregates with a size range of nm to μm and the high viscosity in the polymer film decelerates the temporal evolution of the size and morphology of aggregates.…”