Design and synthesis of novel anthracene derivatives as n-type emitters for electroluminescent devices: a combined experimental and DFT study

Abstract

Six novel anthracene-oxadiazole derivatives, 4a (2-(4-(anthracen-9-yl)phenyl)-5-p-tolyl-1,3,4-oxadiazole), 4b (2-(4-(anthracen-9-yl)phenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), 4c (2-(4-(anthracen-9-yl)phenyl)-5-(4-methoxyphenyl)-1,3,4-oxadiazole), 8a (2-(4-(anthracen-9-yl)phenyl)-5-m-tolyl-1,3,4-oxadiazole), 8b (2-(3-(anthracen-9-yl)phenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole) and 8c (2-(3-(anthracen-9-yl)phenyl)-5-(3,4,5-trimethoxyphenyl)-1,3,4-oxadiazole) have been synthesized and characterized for use as emitters in organic light emitting devices (OLEDs). They show good thermal stability (T(d), 297-364 °C) and glass transition temperatures (T(g)) in the range of 82-98 °C, as seen from the thermo gravimetric analysis and differential scanning calorimetric studies. The solvatochromism phenomenon and electrochemical properties have been studied in detail using UV-Vis absorption, fluorescence spectroscopy and cyclic voltammetry. TD-DFT calculations have been carried out to understand the electrochemical and photophysical properties. The spatial structures of 4b and 8c are further confirmed by X-ray diffraction analysis. Un-optimized non-doped electroluminescent devices were fabricated using these anthracene derivatives as emitters with the following device configuration: ITO (120 nm)/α-NPD (30 nm)/4a-4c or 8a-8c(35 nm)/BCP (6 nm)/Alq3 (28 nm)/LiF (1 nm)/Al (150 nm). Among all the six compounds, 8a displays the maximum brightness of 1728 cd m(-2) and current efficiency 0.89 cd A(-1). Furthermore, as an electron transporter, 8a exhibited superior performance (current efficiency is 11.7 cd A(-1)) than the device using standard Alq3 (current efficiency is 8.69 cd A(-1)), demonstrating its high potential for employment in OLEDs. These results indicate that the new anthracene-oxadiazole derivatives could play an important role in the development of OLEDs.

Synthesis and Photophysical Properties of 9,10-Disubstituted Anthracenes

“…This occurs with respect to both the typical lower-energy progression in the range 350 -400 nm and the higher-energy peak at 260 nm due to S 0 → S 2 transitions (A 1g → B 3u ). A similar insensitivity to 9,10 para substituents was already reported in non-symmetric DPA derivatives with regard to the allowed S 0 → S 1 transition [7] [10] and is in agreement with theoretical calculations showing that only a small fraction of molecular orbitals extends towards the substituents [7] [19]. We suggest that the torsion of the single carbon-carbon bond due to the right-angle twisting of the two 9,10-phenyls [7] is also effective in restraining the conjugation within the anthracene backbone and preventing it from involving the different para substituents.…”

Sunlight light-driven degradation of anthracene and naphthalene on robust Cu2+doped ZnO nanoparticles from simulated rainwater: optimization factors, kinetics, and reusability

“…9 A considerable amount of municipal runoff is released directly, without treatment, into surface water sources such as lakes and rivers, causing risks to humans, sh, and other aquatic life. 10,11 As a result, it is deemed necessary to remove organic molecules from contaminated rainwater before dumping it into water reservoirs. PAHs are primarily consumed by humans through direct contact with polluted water, dietary consumption of PAHcontaining food items, and inhalation.…”

Design, Synthesis and Optoelectronic Properties of Unsymmetrical Oxadiazole Based Indene Substituted Derivatives as Deep Blue Fluoroscent Materials

“…Extensive research has been carried out to promote organic light-emitting diodes (OLEDs) in commercial applications, such as flat-panel displays and solid-state lighting resources, due to their low cost [6][7][8]. OLEDs have been successfully utilized in mobile phones, computers, car stereos, digital cameras, wrist watches and white solid-state lighting [9][10][11].…”