Exploration of Violet-to-blue Thermally Activated Delayed Fluorescence Emitters Based on "CH/N" and "H/CN" Substitutions at Diphenylsulphone Acceptor. A DFT Study

Overview

Journal Front Chem

Specialty Chemistry

Date 2023 Nov 29

PMID 38025080

Authors

Aftab Hussain

Ahmad Irfan

Farah Kanwal

Muhammad Afzal

Aijaz Rasool Chaudhry

Mohamed Hussien

Muhammad Arif Ali

Affiliations

Soon will be listed here.

Abstract

The violet-to-blue thermally activated delayed fluorescence (TADF) emitters were created employing several substituents based on 5,5-dimethyl-5,10-dihydropyrido [2,3-b][1,8] naphthyridine-diphenylsulphone () called via "CH/N" and "H/CN" substitutions at the diphenylsulphone acceptor () moiety. The parent compound was selected from our former work after extensive research employing "CH/N" substitution on Dimethyl-acridine () donor moiety. There is a little overlap amid the highest occupied molecular orbitals (HOMOs) and lowest un-occupied molecular orbitals (LUMOs) due to the distribution of HOMOs and LUMOs primarily on the donor and the acceptor moieties, respectively. It resulted in a narrower energy gap (∆ ) between the lowest singlet (S) and triplet (T) excited state. In nearly all derivatives, the steric hindrance results in a larger torsional angle (85°-98°) between the plane of the and the moieties. The predicted Δ values of the compounds with "H/CN" substitution were lower than those of the comparable "CH/N" substituents, demonstrating the superiority of the reversible inter-system crossing (RISC) from the T → S state. All derivatives have emission wavelengths ( ) in the range of 357-449 nm. The LUMO → HOMO transition energies in the S states are lowered by the presence of -CN groups or -N = atoms at the ortho or meta sites of a acceptor unit, causing the values to red-shift. Furthermore, the showed a greater red-shift as there were more-CN groups or -N = atoms. Three of the derivatives named , , and , emit violet (394 nm, 399 nm, and 398 nm, respectively), while two others, and , emit blue shade (449 nm each) with reasonable emission intensity peak demonstrating that these derivatives are effective violet-to-blue TADF nominees. The lower Δ value for derivative (0.01 eV) with values of 449 nm make this molecule the finest choice for blue TADF emitter amongst all the studied derivatives. We believe our research might lead to the development of more proficient blue TADF-OLEDs in the future.

References

Huang S, Zhang Q, Shiota Y, Nakagawa T, Kuwabara K, Yoshizawa K . Computational Prediction for Singlet- and Triplet-Transition Energies of Charge-Transfer Compounds. J Chem Theory Comput. 2015; 9(9):3872-7. DOI: 10.1021/ct400415r. View

Sun H, Zhong C, Bredas J . Reliable Prediction with Tuned Range-Separated Functionals of the Singlet-Triplet Gap in Organic Emitters for Thermally Activated Delayed Fluorescence. J Chem Theory Comput. 2015; 11(8):3851-8. DOI: 10.1021/acs.jctc.5b00431. View

Hussain A, Kanwal F, Irfan A, Hassan M, Zhang J . Exploring the Influence of Engineering the Linker between the Donor and Acceptor Fragments on Thermally Activated Delayed Fluorescence Characteristics. ACS Omega. 2023; 8(17):15638-15649. PMC: 10157659. DOI: 10.1021/acsomega.3c01098. View

Tao Y, Yuan K, Chen T, Xu P, Li H, Chen R . Thermally activated delayed fluorescence materials towards the breakthrough of organoelectronics. Adv Mater. 2014; 26(47):7931-58. DOI: 10.1002/adma.201402532. View

Chi Y, Chou P . Transition-metal phosphors with cyclometalating ligands: fundamentals and applications. Chem Soc Rev. 2010; 39(2):638-55. DOI: 10.1039/b916237b. View

Zhang Q, Li J, Shizu K, Huang S, Hirata S, Miyazaki H . Design of efficient thermally activated delayed fluorescence materials for pure blue organic light emitting diodes. J Am Chem Soc. 2012; 134(36):14706-9. DOI: 10.1021/ja306538w. View

Deaton J, Switalski S, Kondakov D, Young R, Pawlik T, Giesen D . E-type delayed fluorescence of a phosphine-supported Cu2(mu-NAr2)2 diamond core: harvesting singlet and triplet excitons in OLEDs. J Am Chem Soc. 2010; 132(27):9499-508. DOI: 10.1021/ja1004575. View

Yang S, Wang Y, Peng C, Wu Z, Yuan S, Yu Y . Circularly Polarized Thermally Activated Delayed Fluorescence Emitters in Through-Space Charge Transfer on Asymmetric Spiro Skeletons. J Am Chem Soc. 2020; 142(41):17756-17765. DOI: 10.1021/jacs.0c08980. View

Li W, Li Z, Si C, Wong M, Jinnai K, Gupta A . Organic Long-Persistent Luminescence from a Thermally Activated Delayed Fluorescence Compound. Adv Mater. 2020; 32(45):e2003911. DOI: 10.1002/adma.202003911. View

10.

Endo A, Ogasawara M, Takahashi A, Yokoyama D, Kato Y, Adachi C . Thermally activated delayed fluorescence from Sn(4+)-porphyrin complexes and their application to organic light emitting diodes--a novel mechanism for electroluminescence. Adv Mater. 2010; 21(47):4802-6. DOI: 10.1002/adma.200900983. View

11.

Jiao Y, dordevic L, Mao H, Young R, Jaynes T, Chen H . A Donor-Acceptor [2]Catenane for Visible Light Photocatalysis. J Am Chem Soc. 2021; 143(21):8000-8010. DOI: 10.1021/jacs.1c01493. View

12.

Lu J, Zheng Y, Zhang J . Rational design of phenoxazine-based donor-acceptor-donor thermally activated delayed fluorescent molecules with high performance. Phys Chem Chem Phys. 2015; 17(30):20014-20. DOI: 10.1039/c5cp02810h. View

13.

Kawasumi K, Wu T, Zhu T, Chae H, Van Voorhis T, Baldo M . Thermally Activated Delayed Fluorescence Materials Based on Homoconjugation Effect of Donor-Acceptor Triptycenes. J Am Chem Soc. 2015; 137(37):11908-11. DOI: 10.1021/jacs.5b07932. View

14.

Shuai , Beljonne , Silbey , Bredas . Singlet and triplet exciton formation rates in conjugated polymer light-emitting diodes. Phys Rev Lett. 2000; 84(1):131-4. DOI: 10.1103/PhysRevLett.84.131. View

15.

Zhang Q, Kuwabara H, Potscavage Jr W, Huang S, Hatae Y, Shibata T . Anthraquinone-based intramolecular charge-transfer compounds: computational molecular design, thermally activated delayed fluorescence, and highly efficient red electroluminescence. J Am Chem Soc. 2014; 136(52):18070-81. DOI: 10.1021/ja510144h. View

16.

Wang L, Li T, Feng P, Song Y . Theoretical tuning of the singlet-triplet energy gap to achieve efficient long-wavelength thermally activated delayed fluorescence emitters: the impact of substituents. Phys Chem Chem Phys. 2017; 19(32):21639-21647. DOI: 10.1039/c7cp02615c. View

17.

Cai X, Li X, Xie G, He Z, Gao K, Liu K . "Rate-limited effect" of reverse intersystem crossing process: the key for tuning thermally activated delayed fluorescence lifetime and efficiency roll-off of organic light emitting diodes. Chem Sci. 2018; 7(7):4264-4275. PMC: 6013828. DOI: 10.1039/c6sc00542j. View

18.

Mehes G, Nomura H, Zhang Q, Nakagawa T, Adachi C . Enhanced electroluminescence efficiency in a spiro-acridine derivative through thermally activated delayed fluorescence. Angew Chem Int Ed Engl. 2012; 51(45):11311-5. DOI: 10.1002/anie.201206289. View

19.

Liu M, Seino Y, Chen D, Inomata S, Su S, Sasabe H . Blue thermally activated delayed fluorescence materials based on bis(phenylsulfonyl)benzene derivatives. Chem Commun (Camb). 2015; 51(91):16353-6. DOI: 10.1039/c5cc05435d. View

20.

Liu T, Deng C, Duan K, Tsuboi T, Niu S, Wang D . Zero-Zero Energy-Dominated Degradation in Blue Organic Light-Emitting Diodes Employing Thermally Activated Delayed Fluorescence. ACS Appl Mater Interfaces. 2022; 14(19):22332-22340. DOI: 10.1021/acsami.2c02623. View