Thermally Activated Delayed Fluorescence Materials Based on Homoconjugation Effect of Donor–Acceptor Triptycenes

Donor–acceptor triptycences, TPA-QNX(CN)2 and TPA-PRZ(CN)2, were synthesized and their emissive properties were studied. They exhibited a blue-green fluorescence with emission lifetimes on the order of a microsecond in cyclohexane at room temperature. The long lifetime emission is quenched by O[subscript 2] and is attributed to thermally activated delayed florescence (TADF). Unimolecular TADF is made possible by the separation and weak coupling due to homoconjugation of the HOMO and LUMO on different arms of the three-dimensional donor–acceptor triptycene. Organic light emitting devices (OLEDs) were fabricated using TPA-QNX(CN)2 and TPA-PRZ(CN)2 as emitters which displayed electroluminescence with efficiencies as high as 9.4% EQE.Samsung (Firm)Japan Society for the Promotion of Scienc

Pd(OAc)₂/<i>o</i>-Chloranil/M(OTf)_<i>n</i>: A Catalyst for the Direct C–H Arylation of Polycyclic Aromatic Hydrocarbons with Boryl-, Silyl-, and Unfunctionalized Arenes

Pd(OAc)₂/<i>o</i>-chloranil/M(OTf)_<i>n</i> can effectively promote the C–H arylation of fluoranthene with arylboron compounds or arylsilanes. The reaction takes place with high regioselectivity at the C3 position of fluoranthene. Moreover, the new catalytic system allows the use of unfunctionalized arenes as coupling partners in the arylation of polycyclic aromatic hydrocarbons

Pd(OAc)₂/<i>o</i>-Chloranil/M(OTf)_<i>n</i>: A Catalyst for the Direct C–H Arylation of Polycyclic Aromatic Hydrocarbons with Boryl-, Silyl-, and Unfunctionalized Arenes

Pd(OAc)₂/<i>o</i>-chloranil/M(OTf)_<i>n</i> can effectively promote the C–H arylation of fluoranthene with arylboron compounds or arylsilanes. The reaction takes place with high regioselectivity at the C3 position of fluoranthene. Moreover, the new catalytic system allows the use of unfunctionalized arenes as coupling partners in the arylation of polycyclic aromatic hydrocarbons

Palladium-Catalyzed C–H Activation Taken to the Limit. Flattening an Aromatic Bowl by Total Arylation

All 10 C–H positions on the rim of corannulene can be arylated by repetitive palladium-catalyzed C–H activation. To relieve congestion among the 10 tightly packed aryl substituents in the product, the central corannulene adopts a nearly planar geometry

Palladium-Catalyzed C–H Activation Taken to the Limit. Flattening an Aromatic Bowl by Total Arylation

All 10 C–H positions on the rim of corannulene can be arylated by repetitive palladium-catalyzed C–H activation. To relieve congestion among the 10 tightly packed aryl substituents in the product, the central corannulene adopts a nearly planar geometry