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• 95950-20-2 4,7-bis-(p-methoxyphenyl)-1,10-phenanthroline 

Relevant academic research and scientific papers

Crystal structures and luminescence properties of osmium complexes of cis-1,2-vinylenebis(diphenylarsine) and pyridyl ligands: Possible evidence for metal d, ligand d backbonding

Divalent osmium complexes of the form [Os(N-N)2L-L](PF6-)2 where N-N was a polypyridyl, and L-L was either cis-1,2-bis(diphenylphosphino)ethene (dppene) or cis-1,2-vinylenebis(diphenylarsine) (dpaene) have been synthesized and characterized. X-ray structures were determined for three complexes and for the free dpaene molecule. It was observed that the P-C bond lengths, and C-P-C bond angles do not change significantly when complexed to osmium. It was observed the As-C bond lengths shorten by 2.3 pm and the C-As-C bond angles broaden by 5.6°when dpaene was complexed to osmium. These changes in the arsine structure may indicate a different method of backbonding between arsenic and osmium. It was found that the arsine complexes had absorption and emission that were to the red of analogous phosphine complexes. In violation of "energy gap law", the dpaene complexes were found to have higher quantum yields. This may be due to the way that the arsenic atoms bond to osmium.

Divalent osmium complexes: Synthesis, characterization, strong red phosphorescence, and electrophosphorescence

We report new divalent osmium complexes that feature strong red metal-to-ligand-charge-transfer (MLCT) phosphorescence and electrophosphorescence. The general formula of the complexes is Os(II)(N-N)2L-L, where N-N is either a bipyridine or a phenanthroline and L-L is either a phosphine or an arsine. New polypyridyl ligands synthesized are 4,4′-di(biphenyl)-2,2′-bipyridine (15) and 4,4′-di(diphenyl ether)-2,2′-bipyridine (16), and the 1,10-phenanthroline derivatives synthesized are 4,7-bis(p-methoxyphen-yl)-1,10-phenanthroline (17), 4,7-bis(p-bromophenyl)-1,10-phenanthroline (18), 4,7-bis(4′-phenoxybiphen-4-yl)-1,10-phenanthroline (19), and 4,7-bis(4-naphth-2-ylphenyl)-1,10-phenanthroline (20). 4,4′-Diphenyl-2,2′-bipyridine (21) and 4,7-diphenyl-1,10-phenanthroline (22) were also used in these studies. Strong π-acid ligands used were 1,2-bis(diphenylarseno) ethane (23), cis- 1,2-bis(diphenylphosphino)ethylene (24), and cis-1,2-vinylenebis(diphenylarsine) (25). Ligand 25 is used for the first time in these types of luminescent osmium complexes. These compounds feature strong MLCT absorption bands in the visible region and strong red phosphorescent emission ranging from 611 to 651 nm, with quantum efficiency up to 45% in ethanol solution at room temperature. Red organic light-emitting diodes (OLEDs) were successfully fabricated by doping the Os(II) complexes into blend of poly(N-vinylcarbazole) (PVK) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PBD). Brightness over 1400 cd/m2 for a double-layer device has been reached, with a turn-on voltage of 8 V. The maximum external quantum efficiency was 0.64%. Commission Internationale de I'Eclairage (CIE) chromaticity coordinates (x, y) of the red electrophosphorescence from the complexes are (0.65, 0.34), which indicates pure red emission.