Highly Luminescent π‐Conjugated Terpyridine Derivatives Exhibiting Thermally Activated Delayed Fluorescence

Abstract

Typically, luminescent π-conjugated 2,2':6',2''-terpyridine (tpy) derivatives are versatile components for tridentate metal ligands, supramolecular materials, two-photon absorption bioimaging probes, fluorescent ion sensors, and organic light-emitting devices. However, a limited number of luminescent tpy materials, other than metal complexes, have been reported. This study introduces a series of π-conjugated tpy derivatives that exhibit strong thermally activated delayed fluorescence (TADF). We have observed that a blue tpy emitter outperforms conventional fluorescent emitters. Additionally, a green tpy emitter has exhibited a performance that is almost comparable to that of its green phosphorescent counterparts, realizing an external quantum efficiency close to 25 % and a power efficiency exceeding 80 lm W with an exceptionally low efficiency roll-off. This study demonstrates the first example of highly luminescent tpy-based TADF emitters.

Perspective on carbazole-based organic compounds as emitters and hosts in TADF applications

“…Both materials exhibit higher than 25% singlet exciton formation, which could not be attributed to TTA, TADF or higher-level RISC, yet a triplet polaron-interaction-induced upconversion involving one-electron transfer mechanism was proposed. 134 Sasabe et al 135 introduced a terpyridine unit in combination with an acridine core for TADF applications. When modulated with carbazole units, TADF material AcCz-2TP was prepared with a singlet triplet gap of 0.23 eV, Fig.…”

Nitroxide–nitroxide and nitroxide–metal distance measurements in transition metal complexes with two or three paramagnetic centres give access to thermodynamic and kinetic stabilities

“…The tridentate 2,2′:6′,2′′-terpyridine (tpy) ligand, its derivatives and coordination complexes have played a key role in the synthesis of self-assembled (supra)molecules. Tpy-metal ion complexes exhibit unique electronic, [3][4][5] chemical, [6][7][8] optical, 3,8,9 photovoltaic, 10 and catalytic 6 properties and have been extensively used in medicinal chemistry, 11 materials science 12 and as catalysts. 6 Specifically, tpy-metal complexes are a vivid field of study with wide range of applications such as i) DNA intercalators, 13,14 ii) catalysts in artificial photosynthesis, 5 in Pulsed electron-electron double resonance spectroscopy PELDOR (pulsed electron-electron double resonance or synonymously double electron-electron resonance, DEER) is a pulse EPR technique commonly performed at cryogenic temperatures that allows measurement of distances between unpaired electrons with angstrom resolution.…”

Synthesis of the diketopyrrolopyrrole/terpyridine substituted carbazole derivative based polythiophenes for photovoltaic cells

“…terpyridine moieties also have potential applications in chemical sensors for detecting metal ions and in light-emitting diodes. [16][17][18][19]55 Further modications of the conjugated PTs containing terpyridine moieties and an investigation of their performance are currently underway.…”