Polymorphism of derivatives of tert-butyl substituted acridan and perfluorobiphenyl as sky-blue OLED emitters exhibiting aggregation induced thermally activated delayed fluorescence

Abstract

Blue multi-functional emitters with a perfluorobiphenyl moiety exhibiting polymorphism and changing emission colour.

Thermally Activated Delayed Fluorescence Materials: Towards Realization of High Efficiency through Strategic Small Molecular Design

“…Up to now,t he mostc ommonly adopted EWGs that can potentially induce non-doped TADF are sulfone, [14b] triazine, [14a] benzimidazole, [20f] andc arbonyl-containing groups, [63] etc (Figure 13). The methyl-substituted acridan [64] donor is also Figure 13. Summary of several TADF emittersthat can be fabricated innondopedmanner.…”

Polymorph‐Dependent Thermally Activated Delayed Fluorescence Emitters: Understanding TADF from a Perspective of Aggregation State

“…The O‐crystal also have two conformation molecules, F_O1 and F_O2, which possess different torsion angles and are arranged alternately along the c axis through C−F⋅⋅⋅π, C−H⋅⋅⋅F, and C−H⋅⋅⋅N interactions (Figure d,e). The more crooked forms of DMAC moiety in O‐crystal is considered as the inner reason for its red shift of emission . In R‐crystal, four different conformations (namely, R 1 to R 4 ) can be observed (Figure g).…”

Rational Synthesis of Tetrahydrodibenzophenanthridine and Phenanthroimidazole as Efficient Blue Emitters and their Applications

“…To investigate the effect of the substitution pattern of the derivatives THDP and PI derivatives on their emission behavior, the dependence of their Stokes shifts vs. orientation polarizability of the chosen solvents (Δ f ) were linearly fitted (Figure d). The different slopes (ranging from 2633 to 8511 cm –1 ) of these linear dependencies demonstrated differences in dipole moments of excited singlet states of compounds 3a – j according to the Lippert–Mataga law (Table ) . Different electron‐donating or electron‐accepting substituents of phenyl group attached to PI moiety resulted in slightly different ICT behavior of compounds 3a – j .…”