Thermally activated delayed fluorescence materials with aggregation-induced emission properties: a QM/MM study

Abstract

Based on the quantum mechanics and molecular mechanics (QM/MM) method, theoretical studies reveal the aggregation effect induced TADF mechanism for a 4,4′-(6-(9,9-dimethylacridine-10(9H)-yl)quinoline-2,3-dibenzonitrile (DMAC-CNQ) emitter.

Carbonyl (CO)/N-based thermally activated delayed fluorescent materials with high efficiency and fast reverse intersystem crossing rate: a theoretical design and study

“…The (CT) (0–40%), hybrid local excitation and charge transfer (HLCT) (40–75%) and local excitation (LE) (75–100%) states are defined based on the different S r proportions of the LE component, respectively. 58,80 For the S 1 states, the LE components of these three molecules were below 25%, while the LE component of QAD-Cz was larger than those of the other two molecules. Thus, the holes are mainly distributed on the donor moieties, and the electrons are mainly distributed on the acceptor moieties.…”

Predicting and Designing Thermally Activated Delayed Fluorescence Molecules with Balanced ΔEST and Transition Dipole Moment

“…As a comparison, the experimental results [47] are listed. We predict the amorphous configurations based on the molecular dynamics (MD) simulations [26] with the Materials Studio software. In MD simulations, the Forcite module with the Universal force field [60] is used, while the ensemble of dynamics is NVT with the randomly chosen initial velocity.…”

“…By contrast, the intermolecular 𝜋-𝜋 stacking [24] interaction can be strengthened by the rigid plane structure of TADF molecules, [25] which is unfavorable for the reduction of exciton quenching in the aggregated states. [26] Therefore, it is still a challenge to design efficient OLED materials, on the basis of the photophysical performance dependency of TADF molecules on their geometrical and electronic structures, and aggregation effects. [27,28] Recently, many efforts have been devoted to design efficient TADF molecules by engineering molecular structures based on the structure-property relationships.…”

“…[9,10,[39][40][41] In order to effectively study the aggregation effects, the multiscale quantum mechanics and molecular mechanics (QM/MM) method [42,43] have been applied to investigate the aggregation-induced effect (AIE) [44,45] for efficient luminescent materials. [26] Based on these theoretical investigations, novel efficient TADF molecules (e.g., with considerable radiance rates and extremely fast RISC rates) can be designed. [25,46] In this work, we investigate newly proposed aggregationinduced delayed fluorescent molecules, PyB-DMAC, [47] by using the QM/MM method.…”

A meta-linkage strategy towards high-performance hosts for efficient blue thermally activated delayed fluorescence OLEDs

“…The frontier molecular orbitals and electronic states of m4PO and m3CzPO have been investigated by density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations at the PBE/6-311G(d,p) level. 52 The ground-state molecular geometries of both compounds were highly twisted after optimization. The DFT calculation results show that the HOMO and the LUMO of m4PO are distributed mostly over one of the peripheral diphenylphosphine oxide groups and the central TPPO unit, respectively (Fig.…”