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For efficient white organic light-emitting diodes (OLEDs), it's needed to cover a wide range of visible light area. For these needs, we synthesized new types of yellowish green phosphorescent iridium (III) complexes that have 4-(1-Naphtyl)thieno[3,2-c]pyridine (1-NTP), 4-(2-Naphthyl)thieno[3,2-c]pyridine (2-NTP) or 4-(p-biphenyl)thieno[3,2-c]pyridine (BTP) as main ligands, in addition to chelation with acetylacetonate (acac) as an ancillary ligand. We characterized these phosphors with 1H NMR, mass spectrometer and UV-Vis spectra. The photoluminescence (PL) maxima of iridium(III) complexes appeared at 514, 508 and 512 nm, respectively. Also, these complexes showed shoulder peaks in PL spectra at 550 to 560 nm. The overall luminescent ranges were about 50 nm of FWHM (full width at half maximum). As a result, emission colors of these complexes are closer to yellowish green, and consequently these complexes are good for application of white OLEDs. We also studied their HOMO and LUMO level with cyclic voltammetry (CV). The electroluminescence (EL) study of these complexes is in progress for the applications to white OLEDs. [ABSTRACT FROM AUTHOR]

The new iridium complexes chelated with isoquinoline derivatives as an ancillary ligand were synthesized. The iridium complex phorsphors contained 2-phenylquinoline (pq) or 1-phenylisoquinoline (piq) as main ligands to target orange to red luminescence for the application to two- or three-conponent white organic light-emitting diodes (OLEDs). We introduced 1-(1-Naphthyl)-isoquinoline (1-NAIQ) as an ancillary ligand for new iridium complexes. The photoabroption and photoluminescent (PL) properties were investigated. The PL peaks of (pq)2Ir(1-NAIQ) and (piq)2Ir(1-NAIQ) are shown at 585 and 620 nm, respectively. The ligh emitting wavelength ranges of the complexes were wide with the full widths at half maximum (FWHM) of 94 and 90 nm, respectively. We estimated the HOMO/LUMO levels of these complexes from cyclic voltammetry (CV) curves and the optical band gaps by the aborption spectra. We also compared the photophysical properties of these complexes with well-known red phosphors containing acetylacetonate (acac) as an ancillary ligand. [ABSTRACT FROM AUTHOR]

Two new cationic iridium(III) complexes were synthesized and characterized using oxazoline based ancillary ligand, namely, [Ir(dfppy)2(ibpo)]PF6(Complex 1) and [Ir(ppz)2(ibpo)]PF6(Complex 2), where dfppy is 2-(2,4-difluorophenyl)pyridine, ppz is 1-phenylpyrazole, and ibpo is (S,S)-2,2’-isopropylidene-bis(4-phenyl-2-oxazoline). The absorption, emission, and cyclic voltammetry of the complexes were investigated. Photoluminescence (PL) emission spectra of the complexes in acetonitrile solutions were measured which displays intense photoluminescence maxima in blue (Complex 1) and green (Complex 2) region of the visible spectrum. Light-emitting electrochemical cells (LECs) were fabricated utilizing these complexes and investigated their electroluminescent properties. The devices based on both complexes exhibit green electroluminescence with Commission Internationale de l'Eclairage (CIE) coordinates of (0.46, 0.49) and (0.38, 0.50) for Complexes 1 and 2, respectively. [ABSTRACT FROM PUBLISHER]

For the application to white organic light-emitting diodes (WOLEDs), new orange phosphorescent iridium complexes were designed and prepared. We introduced 1-(8-naphthyl)-isoquinoline ligands (8-NAIQ) to the iridium center along with the ancillary ligands, 2-phenylpyridine (ppy) and 2-phenylquinoline (pq). The resulting iridium complexes synthesized herein are (8-NAIQ)Ir(ppy)2and (8-NAIQ)Ir(pq)2. The photoabsorption, photoluminescence (PL), and electrochemical properties of the irdium complexes synthesized in this study were investigated. The PL spectra of (8-NAIQ)Ir(ppy)2and (8-NAIQ)Ir(pq)2exhibited the luminescence peaks at 536 and 583 nm with the full-width at half-Maximum of 115 and 90 nm, respectively. These complexes exhibited yellow to orange phosphorescence, covering rather wide luminescence wavelength range, which are desirable as orange emitters for two emitting component WOLEDs. [ABSTRACT FROM AUTHOR]

In this study, we report the design, synthesis and characterization of two new cationic iridium(III) complexes employing oxazole based ancillary ligand, namely, and [Ir(ppz)2(mbdiho)]PF6(Complex 1) and [Ir(dfppy)2(mbdiho)]PF6(Complex 2) and its use in light-emitting electrochemical cells (LECs). The design is based on 2-phenylpyrazole (ppz) and 2-(2,4-difluorophenyl)pyridine (dfppy) as cyclometalating ligands and 2,2-Methylenebis[3a,8a-dihydro-8H-indeno[1,2]oxazole] (mbdiho) as ancillary ligand. The effect of substituents in the cyclometalating ligands on the photophysical and electrochemical properties of the complexes has been investigated. The synthesized complexes were used for the fabrication of LEC devices and studied their electroluminescent properties. The complexes incorporated LECs resulted in a higher luminance of 2820 cd m−2and current efficiency of 1.04 cd A−1for Complex 2 than Complex 1. Our work suggests that the light emission of cationic iridium complexes can easily tuned by the substituents present on the cyclometalating ligands which resulted in yellow and green emission for LECs based on Complexes 1 and 2, respectively. [ABSTRACT FROM AUTHOR]