The effects of the rigidity of molecular recognition sites in fluorene-based conjugated polymers P1 and P2 on metal ion sensing have been investigated. The structures of polymers P1 and P2 have twisted 2,2

The novel biphenyl derivative 1, which has planar conformation in crystal at room temperature, is synthesized and investigated by X-ray diffraction. A hydrogen-bonding network, which may be the driving force for the formation of planar conformation, is observed in the crystal of 1. 1 exhibits a strong UV-fluorescent emission in the solid state at room temperature.

A series of

Red electrophosphorescence from light-emitting devices based on a ruthenium(II) complex [Ru(4,7-Ph2-phen)3]2+-doped wide-band-gap semiconductive polymers, e.g., poly(vinylcarbazole) (PVK), polydihexylfluorene (PF), and ladder-like polyphenylene (LPPP), as the emitting layer are reported. These polymers show the short-wavelength electroluminescence emission peaking ranged from 410 to 490 nm, which overlaps well with the absorption band of [Ru(4,7-Ph2-phen)3]2+; however, very efficient energy transfer was investigated in the PVK system, likely due to relative long excited-state lifetimes of PVK than that of PF and LPPP and good chemical compatibility of [Ru(4,7-Ph2-phen)3]2+ with PVK. The EL spectra show the characteristic spectrum of [Ru(4,7-Ph2-phen)3]2+, with a peak at 612nm and CIE of (0.62, 0.37) which is comparable with standard red color. The optimized device ITO/PVK 5wt % [Ru(4,7-Ph2-phen)3]2+/PBD/Alq3/LiF/Al shows the maximum luminance efficiency and power efficiency of 8.6 cd/A and 2.1lm/W, respectively.

The utilization of molecular phosphorescent dyes in polymer-based organic light emitting diodes (OLEDs) was investigated by codoping several phosphorescent dopants into poly(N-vinylcarbazole) (PVK)-based single layer light emitting diodes (LEDs). In particular, green fac-tris(2-phenylpyridine)iridium(III), [Ir(ppy)3], red tris(4,7-diphenyl-1,10-phenanthroline)rhenium dications, [Ru(4,7-Ph2-phen)3]2+, and (2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin)platinum(II) (PtOEP) were used. In the phosphorescence dye doubly doped PVK system ca. x wt % [Ru(4,7-Ph2-phen)3]2+:1wt % Ir(ppy)3:PVK(x) 0.5-5), the intensity ratio (Ri) of red emission vs green emission as a function of doping ratio (Rc) of [Ru(4,7-Ph2-phen)3]2+ vs Ir(ppy)3 is found according to a power-law function with the exponent of 2.0 (0.2 for photoluminescence, which obey the power law with Ri