J. Ramon Vargas

52.2: Hybrid Tandem White OLEDs with High Efficiency and Long Life‐time for AMOLED Displays and Solid‐State Lighting

Excellent performance (61 cd/A efficiency, 27% EQE, 6.2 V, 6500 K white point, 35,000 h half-life) was obtained using 2-stack hybrid tandem white OLED. This is >70% EQE improvement over the all-fluorescent tandem white resulting in >30% reduction in power consumption for a 32″ AMOLED HDTV. Hybrid Tandems for lighting show EQE between 28.4 and − 30.6%, and lifetime between 70,000 and 125,000 h without outcoupling.

P-169: Efficient, Long-Lifetime OLED Host and Dopant Formulations for Full-Color Displays

We report developments in materials and formulations for blue, green, and red fluorescent OLEDs that provide lifetimes exceeding 15,000 h for a model display operating at 200 cd/m2 with a polarizer. In addition, we describe improvements in electron transport and injection that result in a reduction in display power consumption of up to 55%.

30.2: Improving Operating Lifetime of Organic Light‐Emitting Diodes with Perylene and Derivatives as Aggregating Light‐Emitting‐Layer Additives

Aggregating PAHs of the perylene class are useful as LEL additives. They greatly improve the device operating half-life up to 1,000,000 h at the initial luminance of 1540 cd/m2 (20 mA/cm2). There appear to be at least three factors in the lifetime increase: takeover of the LEL functions by the PAHs, aggregation, and an expansion of the recombination and/or emission zone.

Chapter 5.4 Five-membered ring systems: With more than one N atom

Publisher Summary This chapter provides information on five-membered ring systems with more than one N atom. The chapter discusses the following: (1) pyrazoles and ring fused derivatives, (2) imidazoles and ring fused derivatives, (3) 1,2,3-triazoles and ring fused derivatives, (4) 1,2,4-triazoles and ring fused derivatives, and (5) tetrazoles and ring fused derivatives. Among the more interesting reports of pyrazole ring formation is the treatment of cis -aziridinyl ketone tosylhydrazones with sodium ethoxide to afford the pyrazoles, while treatment of the trans -aziridinyl ketones with tosyl hydrazine and polyphosphoric acid provides 2-pyrazolines. Favorski-like ring contraction of oxadiazinone followed by dimerization provides bimane. Imidazoles were incorporated as key elements in the structures of potential antihypertensive agents, a derivative of the antitumor agent temozolomide, the α 2 -adrenoceptor agonist dexmedetomidine, and selective histamine H 3 receptor antagonists. The inexpensive and efficient preparation of imidazole-1-sulfonates from alcohols was reported. Benzimidazoles could be prepared by the condensation of 1,2-diaminobenzenes and orthoesters using KSF clay catalysis under microwave irradiation (MW) without solvent, or at reflux in toluene. Triazoles have been useful reagents in synthesis.