Conjugated Asymmetric Donor‐Substituted 1,3,5‐Triazines: New Host Materials for Blue Phosphorescent Organic Light‐Emitting Diodes

Abstract

Conjugated asymmetric donor-substituted 1,3,5-triazines (ADTs) have been synthesized by nucleophilic substitution of organolithium catalyzed by [Pd(PPh(3))(4)]. Theoretical and experimental investigations show that ADTs possess high solubility and thermostability, high fluorescent quantum yield (35%), low HOMO (-6.0 eV) and LUMO (-2.8 eV), and high triplet energy (E(T), 3.0 eV) according to the different substitution pattern of triazine. The application as host materials for blue PHOLEDs yielded a maximum current efficiency of 20.9 cd A(-1), a maximum external quantum efficiency of 9.8%, and a brightness of 9671 cd m(-2) at 5.4 V, making ADTs good candidates for optoelectronic devices.

Exceptional Blueshifted and Enhanced Aggregation‐Induced Emission of Conjugated Asymmetric Triazines and Their Applications in Superamplified Detection of Explosives

“…As shown in Figure 1, the absorption spectra of dilute solutions of NPhDCzT and DNPhCzT [11] in chloroform and as thin solid films are very similar, in which three distinct absorption bands at around 275, 307, and 320 nm are observed, suggesting the negligible influence of molecular aggregation.…”

“…The target compounds were synthesized according to our previous report. [11] Caution! Highly explosive PA should be used with extreme caution and handled only in small quantities.…”

Understanding the Control of Singlet-Triplet Splitting for Organic Exciton Manipulating: A Combined Theoretical and Experimental Approach

“…The symmetric or asymmetric substitution of various donors or acceptors on three reactive sites of 1,3,5-triazine have resulted in a large number of triazine-based molecules with varied optoelectronic properties 26 . The competition and coordination effects between the substituents, triazine core, and the D-A molecular architecture significantly tuned the molecular energy structures for the singlet and triplet excitons transitions when excited either optically or electronically, and thus leading to rich and/or exceptional optoelectronic properties 27 . Here, we designed a series of triazine-based molecules bearing various donors and acceptors substituted asymmetrically (labeled as A1 , etc.)…”

“…2 , S1 and S2). Triazines of A2 , A3 , and A4 , were experimentally investigated in the literature 27 28 , while S9 and A15 were synthesized in this study (Scheme S1) and their properties were measured to verify the computational results.…”

Star‐Shaped Boron‐Containing Asymmetric Host Materials for Solution‐Processable Phosphorescent Organic Light‐Emitting Diodes

“…It is well known that star‐shaped molecules are promising candidates for solution‐processable optoelectronic devices;19 meanwhile, the asymmetric materials could finely modulate the photophysics and electrochemistry properties by increasing the number of the conformers and amount of energy for crystallization to favor the stability improvement of amorphous film 20. Since carbazole is a weak donor and diphenylamine is a strong one, the competition and cooperation of the different number and types of donors in the star‐shaped symmetry‐breaking D–A molecular architecture would significantly modify the molecular structures and optoelectronic properties of asymmetric molecules.…”