J. Ramon Vargas

Tukaram K. Hatwar; Jeffrey P. Spindler; Marina E. Kondakova; David J. Giesen; Joseph C. Deaton; J. Ramon Vargas

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.

Michele Lee Ricks; J. Ramon Vargas; Kevin P. Klubek; Viktor V. Jarikov; Liang-Sheng Liao; Margaret Jones Helber; William James Begley; Tukaram K. Hatwar; Scott Robert Conley; Lelia Cosimbescu; Christopher T. Brown

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%.

Viktor V. Jarikov; J. Ramon Vargas; Denis Y. Kondakov; Ralph H. Young; Kevin P. Klubek; Liang-Sheng Liao; Christopher T. Brown

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.

Michael A. Walters; J. Ramon Vargas

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.

Viktor V. Jarikov; J. Ramon Vargas

Kevin P. Klubek; Liang-Sheng Liao; Ching Wan Tang; J. Ramon Vargas

Liang-Sheng Liao; Tukaram K. Hatwar; Kevin P. Klubek; J. Ramon Vargas; Dustin L. Comfort

Viktor V. Jarikov; Ralph H. Young; J. Ramon Vargas; Christopher T. Brown; Kevin P. Klubek; Liang-Sheng Liao

Tukaram K. Hatwar; J. Ramon Vargas; Viktor V. Jarikov

Keith B. Kahen; J. Ramon Vargas; Denis Y. Kondakov; Christopher T. Brown; Lelia Cosimbescu; Viktor V. Jarikov