36602-05-8Relevant articles and documents
Electron Push-Pull Effects on Intramolecular Charge Transfer in Perylene-Based Donor-Acceptor Compounds
Ahn, Mina,Kim, Min-Ji,Cho, Dae Won,Wee, Kyung-Ryang
, p. 403 - 413 (2020/12/23)
A series of asymmetric donor-acceptor (D-A) perylene-based compounds, 3-(N,N-bis(4′-(R)-phenyl)amino)perylene (Peri-DPA(R)), were successfully prepared to explore their intramolecular charge transfer (ICT) properties. To induce ICT between the donor and acceptor, diphenylamine (DPA) derivatives (electron donor units) with the same functional groups (R = CN, F, H, Me, or OMe) at both para positions were linked to the C-3 position of perylene to produce five Peri-DPA derivatives. A steady-state spectroscopy study on Peri-DPA(R)s exhibited a progressively regulated ICT trend consistent with the substituent effect as it progressed from the electron-withdrawing group to the electron-donating group. In particular, a comparative study using a D-A-D (donor-acceptor-donor) system demonstrated that not only the electron push-pull substituent effect but also subunit combinations influence photophysical and electrochemical properties. The different ICT characters observed in Lippert-Mataga plots of D-A(CN) and D-A-D(CN) (CN-substituted D-A and D-A-D) led to the investigation on whether ICT emission of two systems with differences in subunit combinations is of the same type or of a different type. The femtosecond transient absorption (fs-TA) spectroscopic results provided direct evidence of ICT origin and confirmed that D-A(CN) and D-A-D(CN) exhibited the same transition mix of ICT (from donor to acceptor) and reverse ICT (rICT, from arylamine to CN unit). Density functional theory (DFT)/TD-DFT calculations support the presence of ICT for all five compounds, and the experimental observations of rICT presented only for CN-substituted compounds.
Aromatic amine derivatives having fluorenyl moiety and organic light-emitting diode including the same
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Paragraph 0268-0270, (2020/03/24)
The present invention relates to aromatic amine derivatives with a fluorene structure and a light-emitting element including the same, and more specifically, to an organic light-emitting compound expressed as [Formula A] and a light-emitting element containing the same. [Formula A] In [Formula A], X1 or X8 and Ar1, Ar2 are specifically defined in the description of the invention.
Electron Push-Pull Effects in 3,9-Bis(p-(R)-diphenylamino)perylene and Constraint on Emission Color Tuning
Ahn, Mina,Kim, Min-Ji,Wee, Kyung-Ryang
, p. 12050 - 12057 (2019/10/11)
A series of perylene-based donor-acceptor-donor (D-A-D) compounds, 3,9-bis(p-(R)-diphenylamino)perylene (R: CN (2a), F (2b), H (2c), Me (2d), and OMe (2e)), was synthesized using 3,9-dibromoperylene with p-(R)-diphenylamine, and the intramolecular charge transfer (ICT) on the D-A-D system with regard to the electron push-pull substituent effect was investigated. By introducing various p-(R)-diphenylamine derivatives with electron-donating or electron-withdrawing R groups, the energy band gaps of the D-A-D compounds were systematically controlled and the emission colors were efficiently tuned from green to red. As expected, the steady state emission spectra of all D-A-D compounds were observed, as well as the emission color controlled, depending on the Hammett substituent constants (σp). In the Lippert-Mataga plots, a different charge-transfer character was observed depending on the electron push-pull substitution, which showed gradually increased ICT characters from the electron-withdrawing to donating substitution. However, exceptionally, the strong electron-withdrawing group of CN-substituted 2a did not correlate with the other R group compounds. From the experimental data and density functional theory calculations, we assume that there is a constraint on emission color tuning to generate higher energy of blue emission in the D-A-D molecular system, due to the reverse charge-transfer property caused by the strong electron-withdrawing group.
