A convenient approach to a series of star-shaped

Indium mediates the coupling of β-bromocrotylbromide with carbonyl compounds in saturated ammonium chloride in the presence of lanthanide triflate under sonication to give the corresponding compouads in good yield and moderate to high syn diastereoselectivity.

A series of novel extended π-conjugated twin molecules based on 10,15-dihydro-5H-diindeno[1,2-r;1´,2´-c]fluorene (truxene) have been prepared via Pd(0)-catalyzed Suzuki coupling, Sonogashira coupling, and McMurry reactions, respectively. 9,9´-Spirobifluorenylene, ethynylene, and vinylene groups as the bridge are introduced to connect both truxene moieties to understand the effect of the large steric chromophores on the properties of the desired materials. The investigation of optical properties of TM1-3 by UV-vis and photoluminescent spectroscopy demonstrates that the optical properties of the twin molecules are strongly affected by the ð-linkages.

Deep blue photoluminescence and electroluminescence are demonstrated from a soluble conjugated polymer, poly (9,9-dihexylfluorene-alt-co-2,5-didecyloxy-para-phenylene). The PL quantum efficiency is approximately 40%. Cyclic voltammetry measurements indicate that the highest occupied molecular orbital and lowest unoccupied molecular orbital energies are 5.66 and 2.62 eV below vacuum, respectively. Single-layer and multilayer light-emitting diodes emit deep blue light (peak at; 420nm).