1829-34-1Relevant articles and documents
Isomers of Coumarin-Based Cyclometalated Ir(III) Complexes with Easily Tuned Phosphorescent Color and Features for Highly Efficient Organic Light-Emitting Diodes
Feng, Zhao,Yu, Yue,Yang, Xiaolong,Zhong, Daokun,Song, Dongdong,Yang, Hua,Chen, Xi,Zhou, Guijiang,Wu, Zhaoxin
, p. 7393 - 7408 (2019)
Three Ir(CλN)2(acac)-type and one Ir(C1λN)(C2λN)(acac)-type coumarin-based cyclometalated Ir(III) complex isomers (IrC5, IrC7, IrC7-A, and IrC8) have been obtained using three coumarin-based isomers of 2-phenylpyridine (ppy)-type cyclometalating ligands (L-C5, L-C7, and L-C8). Two coordination isomers emerging as principal products (IrC7 and IrC7-A) are obtained in the synthesis of corresponding coumarin-based cyclometalated Ir(III) complexes because of two different coordination sites in ligand L-C7 to form a C-Ir bond. To the best of our knowledge, there are no such isomers reported to date. Interestingly, a broad range of phosphorescent color tuning from green (IrC8, λ = 516 nm) to red (IrC5, λ = 608 nm) has been realized through variation of the pyridyl substitution positions on the fused phenyl ring of the coumarin skeleton. In addition, based on natural transition orbital (NTO) analyses, features of the lowest triplet excited states (T1) from these coumarin-based cyclometalated Ir(III) complex isomers can be tuned easily by these ligand isomers as well. IrC5, IrC7, and IrC7-A show prevailing 3MLCT character associated with their T1 states which emit the phosphorescent signals, while the T1 state of IrC8 exhibits the dominant ligand-centered π-π? transition feature. Importantly, owing to the strong rigidity of the coumarin skeleton, all the coumarin-based cyclometalated Ir(III) complex isomers can show high phosphorescent quantum yields φp (ca. 0.4-1). Together with the improved electron-injection/electron-transport (EI/ET) ability, all the phosphorescent emitters display impressive electroluminescence (EL) performance. The device based on IrC8 gives the highest EL efficiencies of external quantum efficiency (ηext) 22.7%, current efficiency (ηL) 79.7 cd A-1, and power efficiency (ηP) 58.2 lm W-1, representing the most state-of-the-art EL ability ever achieved by coumarin-based phosphorescent emitters. All these encouraging data definitely suggest the great potential of the coumarin skeleton in both easy tuning of the photophysical properties of ppy-type Ir(III) phosphorescent complexes and developing high-performance phosphorescent emitters.
An Oxidative Dearomatization Approach to Tetrodotoxin via a Masked ortho-Benzoquinone
Robins, Jacob G.,Johnson, Jeffrey S.
supporting information, p. 559 - 563 (2022/01/20)
Progress toward a stereoselective synthesis of tetrodotoxin (TTX) is presented. Oxidative dearomatization of a tetrasubstituted guaiacol arene yielded a masked ortho-benzoquinone that intercepted an acyl nitroso species generated in situ by the copper-cat
Compound containing benzo five-membered heterocyclic structure and preparation method and application thereof
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Paragraph 0082-0086, (2021/08/14)
The invention relates to the field of medicinal chemistry, and discloses a compound containing a benzo five-membered heterocyclic structure as well as a preparation method and application thereof. The invention also discloses a composition containing the benzo five-membered heterocyclic compound or the pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier, and application of the composition in preparation of PARP-1 and ERK inhibitors. The compound can be used for treating diseases such as tumors.