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Utilizing 1,3,4-oxadiazole amide that possesses outstanding electron mobility to serve as auxiliary ligands, four novel iridium (III) complexes of Ir1 – Ir4 were prepared. Their structure, photophysical, and electrochemical characteristics were examined in detail, and quantum chemical calculations were used to interpret their photophysical behaviors. At room temperature, complexes Ir1 and Ir2 exhibit almost coincident green phosphorescence with peaks at 506 nm. Ir3 and Ir4 complexes produce greenish blue and greenish yellow light with a double-peak structure located at 496 and 531 nm. Organic light-emitting diodes utilizing Ir1 – Ir4 as emitters exert extremely moderate efficiency roll-off, which is caused by the emitters bearing CF 3 -substituted 1,3,4-oxadiazole amide possessing excellent electron mobility. [Display omitted] • Iridium complexes Ir1–Ir4 with CF 3 -substituted 1,3,4-oxadiazole amide ancillary ligands are synthesized. • Both Ir1 and Ir2 exhibit green phosphorescence, Ir3 and Ir4 produce greenish blue and greenish yellow light, respectively. • Complexes Ir1–Ir4 have excellent thermal and electrochemical stability. • The OLEDs based on Ir1–Ir4 exhibit very mild efficiency roll-off. [ABSTRACT FROM AUTHOR]

Three novel iridium(III) complexes bearing oxadiazol-substituted amide ligands have been synthesized and characterized, and the photophysical and electrochemical properties have been investigated. All the complexes exhibit blue light emission with major peaks at 472, 468 and 462 nm in acetonitrile solutions, respectively. Both photophysical properties and quantum chemical calculations demonstrate that photoluminescence of these complexes are mainly from cyclometalated ligand-based 3 π−π* excited states. Using these complexes as emitters, the organic light-emitting diodes with single- or double-emitting layers were fabricated. The devices with double-emitting layers exhibit good electroluminescence performances with the maximum current efficiencies of 10.5, 6.3 and 4.6 cd A −1 , respectively, and mild efficiency roll-off. [ABSTRACT FROM AUTHOR]

Two new cationic iridium complexes bearing cyclometalated carbene ligands have been prepared, and the photophysical and electrochemical properties have been investigated. In degassed acetonitrile solutions, these complexes exhibit yellow light emission with peaks at 591 and 579 nm, respectively. Both photophysical properties and quantum chemical calculations indicate that photoluminescence of these complexes are mainly from triplet charge-transfer excited states. Solution-processed organic light-emitting diodes based on these complexes exhibit yellow electroluminescences with the maximum current efficiencies of 17.42 and 6.36 cd A −1 and Commission Internationale d’Énclairage(x, y) coordinates (CIE x,y ) of (0.47, 0.51) and (0.51, 0.47), respectively. [ABSTRACT FROM AUTHOR]

Two new cationic iridium complexes with nonconjugated bis(pyrazole-1-yl)methane as the ancillary ligand have been prepared, and crystal structure, photophysical and electrochemical properties have been investigated. In degassed acetonitrile solutions, these complexes exhibit blue light emission with peaks at 456 and 453 nm, respectively. Both photophysical properties and quantum chemical calculations indicate that photoluminescence of these complexes are mainly from ligand-centered 3 π → π*. Solution-processed organic light-emitting diodes based on these complexes exibit blue light emission with the maximum current efficiencies of 7.34 and 5.36 cd A −1 , and maximum external quantum efficiencies of 4.06 and 2.66%, respectively. [ABSTRACT FROM AUTHOR]

With flexible 2-methylenesuccinate acid (H 2 MSA) and rigid 4, 4′-bipyridine (bpy) as mixed ligands, two three-dimensional (3D) metal−organic frameworks (MOFs), {[Zn 3 (μ 2 -OH) 2 (MSA) 2 (bpy) 2 ]·4H 2 O} n (1) and {[Cd(MSA)(bpy)]·2H 2 O} n (2), were obtained solvothermally. Complexes 1 and 2 both have a 3D framework structures, which include respectively a linear trinuclear [Zn 3 ] or a rare dinuclear [Cd 2 ] cluster node that consisting of two seven-coordinated Cd(II) ions. The adjacent [Zn 3 ] or [Cd 2 ] nodes in 1 and 2 are firstly linked together by the MSA2− ligand to form a 1D chain or a 2D layer unit respectively, which are further bridged by the bpy linkers to produce the 3D framework structures. If treating the [Zn 3 ] and [Cd 2 ] cluster as 4- and 6-connected nodes, the 3D frameworks of 1 and 2 can be simplified into a CdSO 4 topological network with a Schläfli symbol of (65.8) and a rob network with a Schläfli symbol of (48.66.8), respectively. The PXRD patterns suggest that 1 and 2 have good stability when soaked in water for at least 48 h. The fluorescence sensing properties of 1 and 2 toward different metal inorganic ions were investigated, and two complexes both could sense Fe3+, MnO 4 − and Cr 2 O 7 2− in aqueous solution with high sensitivity and selectivity (the LODs were 3.20 μM, 1.54 μM and 1.95 μM for 1 , 1.15 μM, 0.48 μM and 1.23 μM for 2 , respectively) as well as good recircularity. In addition, the mechanism of the selective luminescence quenching response for Fe3+, MnO 4 − and Cr 2 O 7 2− could be attributed to the energy competition between the excitation of complex 1 / 2 and the ultraviolet absorption of responsive substances. [Display omitted] • Two 3D luminescent MOFs were obtained by a strategy of rigid-flexible co-linkers. • The frameworks contain rare linear trinuclear [Zn 3 ] or dinuclear [Cd 2 ] cluster units respectively. • The complexes displayed good luminescent properties in water. • The complexes could behave as multi-target probes to sense Fe3+, MnO 4 − and Cr 2 O 7 2− with high sensitivity and selectivity. [ABSTRACT FROM AUTHOR]

Three new yellow-emitting cationic iridium complexes have been prepared, and the photophysical and electrochemical properties have been investigated. These cationic iridium complexes have excellent thermal stability and can be thermally vacuum-sublimed as phosphorescent dyes for the fabrication of efficient organic light-emitting diodes. The devices based on these complexes give yellow-green electroluminescences with Commission Internationale de L'Eclairage coordinates of (0.38, 0.58), (0.37, 0.58), (0.38, 0.58). The maximum current efficiencies of devices based on these complexes are 20.2, 23.7 and 21.5 cd A −1 that corresponds to maximum external quantum efficiencies of 6.3%, 6.8% and 6.5%, respectively. [ABSTRACT FROM AUTHOR]