A Facile Synthesis of the Unsymmetrically Methyl-Substituted 2-Hydroxybiphenyls by the Regioselective Cleavage of Dibenzofuran Derivatives with Lithium Metal
large solvent effect is observed in Friedel–Crafts acylation of 1,2,3,4-tetramethyldibenzofuran (TMD). 8-Acyl-TMD is by far the major product in nitrohydrocarbons while 7-acyl-TMD is favoured in chloro-hydrocarbons and is the major product in many cases. The influence of temperature, and the nature of the reaction medium, acylating agents, and added nitro-compounds on the isomerdistribution, are examined
COMPOUND, ELECTRON TRANSPORT MATERIAL, DISPLAY PANEL AND DISPLAY APPARATUS
申请人:Shanghai Tianma AM-OLED Co., Ltd.
公开号:US20210130355A1
公开(公告)日:2021-05-06
The present disclosure provides a compound having a structure represented by Formula 1, where X
1
-X
4
are each independently selected from a carbon atom or a nitrogen atom, and at least two of X
1
-X
4
are each a nitrogen atom; R
1
-R
4
are independently absent or selected from hydrogen, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkylthio, C1-C20 alkylamino, C6-C30 aryl, or C2-C30 heteroaryl; m is 1 or 2; n and q are each independently selected from 0, 1, or 2, n+q≥1, and m+n+q=3; Ar is C6-C30 aryl. The molecular structure of the compound has a nitrogen-containing multidentate ligand suitable to form complexes with metal Yb or LiQ to form a metal organic complex having multidentate bondings. When applied to an OLED device, it can effectively lower the turn-on voltage and operating voltage, improve the efficiency, and prolong lifetime of the OLED device.