A Donor–Acceptor Cage for Thermally Activated Delayed Fluorescence: toward a New Kind of TADF Exciplex Emitters

Abstract

We present the rational design of an organic cage combining an electron-donating (D) triazatruxene and electron-accepting (A) triphenyl triazine connected by three electronically inert pillars. This controlled architecture leads to a precise spatial separation and cofacial alignment of the D and A motifs. Such an architecture induces an efficient intramolecular through-space charge transfer (TSCT), providing a small singlet−triplet energy difference (ΔE ST ) of 0.049 eV, and thus gives rise to a thermally activated delayed fluorescence (TADF) macrocyclic exciplex emitter.

Nitrogen-rich porous organic cages with high acetylene storage and separation performance

“…[14][15][16] Since their inception in 2009 from Cooper's group, 17 research on the design and synthesis of different linkages, shapes, topologies, sizes, and functions of POCs has attracted much attention from chemists and materials scientists. [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] Our group focuses on using concave-shaped calix [4]resorcinarene (C4RA) as synthons in construction of novel C4RA-based POCs and their applications. [34][35][36][37][38][39][40] In this work, we designed and synthesized two robust nitrogen-rich POCs aiming at efficient storage and separation of C 2 H 2 , as the basic nitrogen groups have been veried to have strong interaction with acidic C 2 H 2 gas.…”

A donor–acceptor cage for circularly polarized TADF emission

“…[21][22][23][24] To design CP-TADF, both chirality for circularly polarized luminescence (CPL) and the prerequisite of the small energy difference between the lowest singlet (S 1 ) and triplet (T 1 ) excited states (DE ST ) for TADF 25 should be fulfilled. Ealier study 26 showed that organic cages composed of electron donor and acceptor moieties exhibit efficient TADF emission via intramolecular through-space charge transfer (TSCT). 27,28 By reasoning that molecular chirality and TSCT can be induced simultaneously by the spatial arrangement of achiral/prochiral donors and acceptors, we herein report the first example of an organic cage, denoted DA-2, that exhibits CP-TADF.…”

Thermally Activated Delayed Fluorescent Emitters Based on Cyanobenzene Exhibiting Fast Reverse Intersystem Crossing to Suppress the Efficiency Roll-Off

“…In the last two decades, organic light-emitting diodes (OLEDs) have attracted great attentions owing to the use of the triplet excited-available emitters. − As one promising type of these emitters, thermally activated delayed fluorescent (TADF) emitters are capable of pushing 75% triplet excitons to emit via the reverse intersystem crossing (RISC) process, and theoretically the 100% internal quantum efficiency (IQE) can be achieved. − However, the ultralong delayed lifetime usually leads to the serious fluorescence quenching in aggregate states. As a result, the luminescent efficiency is sharply compromised in OLEDs under high current density, which is called efficiency roll-off. , …”