Related Experiment Video
Updated: May 19, 2026

Scale-up Chemical Synthesis of Thermally-activated Delayed Fluorescence Emitters Based on the Dibenzothiophene-S,S-Dioxide Core
Published on: October 24, 2017
Chiral Through-Space Charge-Transfer Thermally Activated Delayed Fluorescent Emitter with Multiple Stereogenic
Minqiang Mai1, Zequan Tao1, Jianping Zhou1
1Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, China.
None:
The development of high-performance circularly polarized thermally activated delayed fluorescence (CP-TADF) emitters featuring through-space charge-transfer (TSCT) transitions is fascinating yet challenging due to the difficulty in balancing efficiency, dissymmetry factors, and structural diversity. Here, we report the first helical-configuration integrated TSCT-type CP-TADF emitter, which adopts a dual-spiro-locked face-to-face acceptor/donor/acceptor scaffold. This sandwiched design not only enables degenerate energy states via multi-channel TSCT transitions but also incorporates multiple stereogenic centers, resulting in an exceptionally small singlet-triplet energy gap of 0.04 eV, a high reverse intersystem crossing rate of >106 s- 1, and near-unity photoluminescence quantum yields (>93%), accompanied by a benchmark high photoluminescence dissymmetry factor (|gPL|) of 4.4 × 10- 3 among such TSCT-type emitters. When applied as an emitter in organic light-emitting diodes (OLEDs), this molecule achieves a maximum external quantum efficiency (EQEmax) of 27.4% with suppressed efficiency roll-off and strong electroluminescence dissymmetry (|gEL| ≈ 3.2 × 10- 3). When used as a sensitizer for a multiple-resonance TADF emitter, it enables an impressive maximum external quantum efficiency (EQEmax) of 38.4% while maintaining high |gEL| (≈ 3.0 × 10- 3). This work greatly diversifies the structural frameworks of TSCT-type CP-TADF emitter with improved performance.
Related Concept Videos
Molecules with Multiple Chiral Centers
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Chirality at Nitrogen, Phosphorus, and Sulfur
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Prochirality

