1,3,6,8-Tetrasubstituted Pyrenes: Solution-Processable Materials for Application in Organic Electronics

Abstract

A series of star-shaped organic semiconductors have been synthesized from 1,3,6,8-tetrabromopyrene. The materials are soluble in common organic solvents allowing for solution processing of devices such as light-emitting diodes (OLEDs). One of the materials, 1,3,6,8-tetrakis(4-butoxyphenyl)pyrene, has been used as the active emitting layer in simple solution-processed OLEDs with deep blue emission (CIE = 0.15, 0.18) and maximum efficiencies and brightness levels of 2.56 cd/A and >5000 cd/m(2), respectively.

Blue Light Emitting Polyphenylene Dendrimers with Bipolar Charge Transport Moieties

“…The band with a maximum at 319 nm can be assigned to the absorption of PBD [38], similar to that of PYPBD (a pyrene-cored polyphenylene dendrimer with PBDs in the periphery, see Scheme S1). The other band (λ max : 392 nm, ε:~50,000 L·mol −1 ·cm −1 ) is much sharper and originates from π-π* transitions of the pyrene core [24,40,41]. Both dendrimers are readily soluble (≥8 g/L) in organic solvents, e.g., DCM, THF and toluene.…”

“…The band with a maximum at 319 nm can be assigned to the absorption of PBD [38], similar to that of PYPBD (a pyrene-cored polyphenylene dendrimer with PBDs in the periphery, see Scheme S1). The other band (λmax: 392 nm, ε: ~50000 L·mol −1 ·cm −1 ) is much sharper and originates from π-π* transitions of the pyrene core [24,40,41]. The photoluminescence spectra (PL) of these dendrimers showed that the emission of the donoracceptor dendrimers, PYCAB and PYPBD were all identical (λmax: ~431 nm and a weak shoulder: ~455 nm) both for excitation of the surface and the core groups (Figure 2), revealing that the emission of the donor-acceptor dendrimers can be attributed to an efficient surface-to-core energy transfer [24,40,41].…”

“…In addition, a TPA-and PBD-functionalized dendrimer D2 was prepared for comparison. The emission of CAB [37], PBD [38] and TPA [39] show good overlaps with the absorption of the core, i.e., 1,3,6,8-tetraphenylpyrene [40,41], for efficient surface-to-core energy transfers. For this purpose, shape-persistent polyphenylene dendrimers enable generation-by-generation (core-shell-surface) functionalization and OLEDs utilizing efficient surface-to-core energy transfers of pyrene-cored polyphenylene dendrimers have been reported [22][23][24].…”

“…In addition, a TPA-and PBD-functionalized dendrimer D2 was prepared for comparison. The emission of CAB [37], PBD [38] and TPA [39] show good overlaps with the absorption of the core, i.e., 1,3,6,8-tetraphenylpyrene [40,41], for efficient surface-to-core energy transfers. To summarize, in this contribution a new method to make polyphenylene dendrimers with donor-acceptor periphery is introduced.…”

Pyrene-cored blue-light emitting [4]helicenes: synthesis, crystal structures, and photophysical properties

“…Furthermore, the calculated HOMO values of 7a-c and 9 vary slightly in the range − 5.89 to − 5.78 eV, indicating that the materials are promising deep-blue emitters for applications in OLED-like optoelectronic devices. 33 All data of electrochemical 40 characteristics for the pyrenes 7ac and 9 are also summarized in Table 2.…”