The photophysical properties of chromophores at high (100 mM and above) concentrations in polymers and as neat solids

Abstract

The absorption, fluorescence, and photostability of five conjugated chromophores: perylene, 2,5,8,11-tetra-t-butyl perylene (TTBP), perylene orange (PO), perylene red (PR), and a zwitterionic Meisenheimer complex (MHC), are studied as a function of concentration in poly(methyl methacrylate) (PMMA). At 1 mM concentrations, all five molecules exhibit properties consistent with unaggregated chromophores. At higher concentrations, perylene and PO both exhibit excimer formation, while TTBP, PR, and the MHC retain their monomeric fluorescent lineshapes. In these three molecules, however, the fluorescence decay times decrease by 10% (TTBP) to 50% (MHC) at concentrations of 100 mM in PMMA. The fluorescence properties of these highly concentrated samples are sensitive to the sample preparation conditions. In the neat solid where the effective concentration is on the order of 1 M, all three molecules exhibit very fast fluorescence decays, on the order of 150 ps or less, despite the fact that they retain their basic monomeric fluorescence lineshape. In addition to the enhanced nonradiative decay at high concentrations, these three molecules also undergo a concentration-dependent photobleaching. The combined effects of intermolecular nonradiative decay channels and photobleaching appear to be a general obstacle to achieving highly concentrated dye-doped solids.

Tailoring Colors by O Annulation of Polycyclic Aromatic Hydrocarbons

“…Friedel–Crafts alkylation of perylene by the protocol of Pillow et al 57. in the presence of a large excess of t BuCl58, 59, 60 leads to an inseparable mixture of di‐, tri‐, and tetrasubstituted t Bu‐perylene derivatives. The unpurified perylene mixture was subsequently submitted to a selective C−H borylation reaction in the presence of 10 mol % of [{Ir(COD)(OMe)} 2 ] (COD=1,5‐cyclooctadiene) catalyst and 20 mol % of 4,4′‐di‐tert‐butyl‐2,2′‐bipyridyl (dtbpy) and B 2 pin 2 (pin=pinacolato) in n ‐hexane at 80 °C for 24 h,61 which allowed the isolation of tetra‐ tert ‐butylperylene 1 a as well as mono‐ and bis‐boronic esters 1 b and 1 c (for X‐ray structure, see Supporting Information) in 33, 20 and 30 % yield, respectively.…”

Thirty Years of Luminescent Solar Concentrator Research: Solar Energy for the Built Environment

“…Furthermore, the tertraphenoxy-substituted perylene bisimides (Figure 10r) have good solubility in organic matrices due to the phenoxy side groups, especially in comparison to the chlorinated perylene bisimides (Figure 10q). Component 10r has an absorption band peaking at 578 nm and an emission band peaking at 613 nm with a quantum yield of 96% with both good solubility [129] and photostability.…”

Energy transfer in pendant perylene diimide copolymers

“…Solid SP20:1:0 showed short emission lifetimes at shorter wavelengths, increasing at longer wavelengths (Figure 5 (a) and (b)). Like other luminophores in polymeric systems, [41][42][43][44][45][46][47] the SM luminophores display a range of excitation energies due to aggregation, different microenvironments and conformations in the disordered solid polymer. Homo-FRET between like-luminophores in different energy configurations is then possible, leading to the large observed redward shift.…”

“…The polymer films reported in this paper have high concentrations of perylene units. While highly concentrated perylenedoped polymer films (1 − 3 M) have been prepared in previous work, 14,29,43 the majority of the literature reports perylene doped polymer films of 5 × 10 −4 − 5 × 10 −2 M 44,45 and weight percentages of 0.006 − 5%. 35,46,47,51 We present perylene films with concentrations in the range of 0.05-0.31M and 18-30 wt%.…”