Treatment of a series of dinuclear Ir(III) complexes [(fnazo)(2)Ir(μ-Cl](2), [(fpiq)(2)Ir(μ-Cl](2), and [(fppy)(2)Ir(μ-Cl](2) with diphenyl(1-naphthyl)phosphine (dpnH) in decalin at 100 °C afforded the simple adducts, trans-N,N'-[(fnazo)(2)Ir(dpnH)Cl] (1a), trans-N,N'-[(fpiq)(2)Ir(dpnH)Cl] (1b), and trans-N,N'-[(fppy)(2)Ir(dpnH)Cl] (1c), for which the C(∧)N cyclometalating reagents, that is, fnazoH, fpiqH and fppyH, stands for 4-(4-fluorophenyl)quinazoline, 1-(4-fluorophenyl)isoquinoline and 4-fluorophenylpyridine, respectively. Single crystal X-ray diffraction study on 1a revealed existence of two trans-N,N' cyclometalates, with both chloride and dpnH donors located at the positions opposite to the phenyl substituents. Subsequent heating of 1a-1c at higher temperature afforded the second isomer (2a-2c), showing formation of cis-N,N' orientation for the aforementioned cyclometalates. Further thermolysis of either trans or cis-Ir(III) complexes 1 or 2 in presence of sodium acetate, which serves as both activator and chloride scavenger, gave successful isolation of a mixture of two fully cyclometalated Ir(III) complexes trans-N,N'-[(C(∧)N)(2)Ir(dpn)] (3a-3c) and cis-N,N'-[(C(∧)N)(2)Ir(dpn)] (4a-4c). Structural and photophysical properties of complexes 3a-3c and 4a-4c were measured and compared. Time-dependent density functional theory (DFT) studies suggested that, upon changing the C(∧)N cyclometalates from quinazolinyl, isoquinolinyl, and, finally, to pyridyl fragment, the lowest unoccupied molecular orbitals (LUMOs) are gradually shifted from the cyclometalating nitrogen heterocycles to the 1-naphthyl group of the phosphine chelate and, concomitantly altered the photophysical properties. An organic light-emitting diode (OLED) using orange-red phosphors 4a and 4b has been successfully fabricated. At the practical brightness of 500 cd·m(-2), decent external quantum efficiency of 10.6% and 12.5% could be reached for 4a and 4b, respectively, revealing the usefulness of relevant molecular architecture in designing triplet OLED emitters.

Preparation and characterization of a new class of emissive Os(II) complexes ( 1 -5 ) have been achieved using 3-(thiazol-2-yl), 3-(benzothiazol-2-yl), 3-(imidazol-2-yl) and 3-(benzimidazol-2-yl) azole chelates, together with the incorporation of one diphosphine ancillary for satisfying the octahedral coordination arrangement. The resulting Os(II) complexes, except for 5 , all show bright emission spanning visible region from green to saturated red, and their structural versus spectroscopic properties have been comprehended by absorption/emission together with computational approaches. Subsequently, a series of solution-processed OLEDs using 1 -4 as the dopant were successfully fabricated, demonstrating excellent device performances with external quantum effi ciency (EQE) of 15%, current effi ciency exceeding 48 cd/A, and power conversion effi ciency up to 50 lm/W. Complex 4 is the only Os(II) based phosphor so far suitable for the fabrication of highly effi cient green-emitting OLEDs.

A series of Os(II) sensitizers (TFOS-x, in which x=1, 2, or 3) with a single 4,4'-dicarboxy-2,2'-dipyridine (H2 dcbpy) anchor and two chelating 2-pyridyl (or 2-pyrimidyl) triazolate ancillaries was successfully prepared. Single-crystal X-ray structural analysis showed that the core geometry of the Os(II) -based sensitizers consisted of one H2 dcbpy unit and two eclipsed cis-triazolate fragments; this was notably different from the Ru(II) -based counterparts, in which the azolate (both pyrazolate and triazolate) fragments are located at the mutual trans-positions. The basic properties were extensively probed by using spectroscopic and electrochemical methods as well as time-dependent density functional theory (TD-DFT) calculations. Fabrication of dye-sensitized solar cells (DSCs) was then attempted by using the I(-) /I3 (-) -based electrolyte solution. One such DSC device, which utilized TFOS-2 as the sensitizer, showed promising performance characteristics with a short-circuit current density (JSC ) of 15.7 mA cm(-2) , an open-circuit voltage of 610 mV, a fill factor of 0.63, and a power conversion efficiency of 6.08 % under AM 1.5G simulated one-sun irradiation. Importantly, adequate incident photon-to-current conversion efficiency performances were observed for all TFOS derivatives over the wide spectral region of 450 to 950 nm, showing a panchromatic light harvesting capability that extended into the near-infrared regime. Our results underlined a feasible strategy for maximizing JSC and increasing the efficiency of DSCs.

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A new partial fluorinated polymer shows excellent charge storage capability. The electrets materials can be employed in consumer electronic products widely, aided with the flexible, extremely light and thin property. Applications on speakers and electrets touch panels will be discussed in this paper.