Tröger's Base-Derived Thermally Activated Delayed Fluorescence Dopant for Efficient Deep-Blue Organic Light-Emitting Diodes.

The development of efficient deep-blue emitters with thermally activated delayed fluorescence (TADF) properties is a highly significant but challenging task in the field of organic light-emitting diode (OLED) applications. Herein, we report the design and synthesis of two new 4,10-dimethyl-6H,12H-5,11-methanodibenzo[][1,5]diazocine ()-derived TADF emitters, and , which feature distinct benzophenone ()-derived acceptors but share the same dimethylacridin () donors. Our comparative study reveals that the amide acceptor in exhibits a significantly weaker electron-withdrawing ability in comparison to that of the typical benzophenone acceptor employed in .

A New Species of (Myricaceae) from the Early Miocene of Central Inner Mongolia, China, and Phytogeographic History of Sweet-Fern.

(Myricaceae) is well known as a monotypic genus living only in eastern North America; however, fossils show that the genus occurred extensively in the Northern Hemisphere during the Cenozoic. We observed dozens of leaf fossils from the early Miocene in Zhuozi, China. The leaf architecture characteristics and epidermal features of the fossil specimens are described in detail here for the first time, and they were assigned to a new species: .