54110-33-7Relevant academic research and scientific papers
Color Tuning of Efficient Electroluminescence in the Blue and Green Regions Using Heteroleptic Iridium Complexes with 2-Phenoxyoxazole Ancillary Ligands
Benjamin, Helen,Liang, Jie,Liu, Yu,Geng, Yun,Liu, Xingman,Zhu, Dongxia,Batsanov, Andrei S.,Bryce, Martin R.
, p. 1810 - 1821 (2017)
A rational molecular design strategy for tuning the emission color of phosphorescent complexes by functionalization of the bis(2-phenylpyridine)(2-(2′-oxyphenyl)-2-oxazoline/oxazole)iridium(III) framework is reported. Five new complexes (2-6) have been synthesized in good yields and characterized by cyclic voltammetry, absorption, and photoluminescence studies, by time-dependent density functional theory (TD-DFT) calculations, and by single-crystal X-ray diffraction studies for complexes 2, 4, and 6. An interesting feature of the complexes is that the HOMO is localized on the Ir d-orbitals and the phenoxylate part of the “ancillary” ligand, while the LUMO is located on the pyridyl ring of the ppy ligands. A few other complexes containing 2′-oxyphenyl-2-oxazoline/oxazole ancillary ligands have been reported previously; however, until now there has not been a systematic investigation into manipulating this unusual frontier orbital distribution to tune the emissive properties. It is shown that exchanging the phenylpyridine (ppy) ligand for 2,4-difluoro-ppy gives a blue shift of 21-22 nm (from 1 to 2 and from 4 to 5), and the introduction of electron-withdrawing substituents (SO2Me, CF3) onto the phenoxylate ring of the (2′-oxyphenyl)-2-oxazole ligand results in a further blue shift of 13-20 nm. Combining these functionalizations gives sky-blue emission with λmaxPL 476 and 479 nm for complexes 5 and 6 in dichloromethane solution. The solution quantum yields of all the complexes are within the range ΦPL 0.42-0.73. The observed lifetimes (τobs = 1.52-3.01 μs) and spectral profiles are indicative of phosphorescence from a mixture of ligand-centered and MLCT excited states. (TD-)DFT calculations are in close agreement with the observed photophysical and electrochemical properties of the complexes. Phosphorescent organic light-emitting diodes have been fabricated using complexes 2, 3, 5, and 6 as the emitter, doped in a 4,4′-bis(N-carbazolyl)biphenyl host, giving efficient emission in the blue-green region. Notably, complex 5 gives λmaxEL 480 nm with a maximum brightness of 26150 cd m-2.
Rational approach to highly potent and selective apoptosis signal-regulating kinase 1 (ASK1) inhibitors
Lovering, Frank,Morgan, Paul,Allais, Christophe,Aulabaugh, Ann,Brodfuehrer, Joanne,Chang, Jeanne,Coe, Jotham,Ding, WeiDong,Dowty, Heather,Fleming, Margaret,Frisbie, Richard,Guzova, Julia,Hepworth, David,Jasti, Jayasankar,Kortum, Steve,Kurumbail, Ravi,Mohan, Shashi,Papaioannou, Nikolaos,Strohbach, Joseph W.,Vincent, Fabien,Lee, Katherine,Zapf, Christoph W.
, p. 606 - 621 (2018/01/19)
Many diseases are believed to be driven by pathological levels of reactive oxygen species (ROS) and oxidative stress has long been recognized as a driver for inflammatory disorders. Apoptosis signal-regulating kinase 1 (ASK1) has been reported to be activ
