Efficient blue light-emitting diodes based on a classical "push-pull" architecture molecule 4,4 prime -di-(2-(2,5- dimethoxyphenyl)ethenyl)-2,2 prime -bipyridine

A novel, highly blue luminescent molecule containing donor and acceptor groups, 4,4 prime -di-(2-(2,5-dimethoxyphenyl)ethenyl)-2,2 prime -bipyridine, that shows photoluminescence emission at 450 nm with 43% quantum yield is designed and synthesized. Time dependent-DFT calculations show an excellent correlation between theoretical and experimental absorption spectra, thus allowing for a detailed description of the electronic structure and assignment of the main absorption features. An optimized organic light-emitting diode based on a 4,4 prime -di-(2-(2,5-dimethoxyphenyl)ethenyl)-2,2 prime -bipyridine blue emitting layer, with a 4,4 prime ,4 double prime -tris(carbazol-9-yl)-triphenylamine) hole transporting layer, a 2,9-dimethyl-4.7-diphenyl-phenatroline hole blocking layer, and a tris(8-hydroxyquinoline)aluminium electron transport layer exhibited 2.1% quantum efficiency.