Cyclometalated arylpyridine and arylisoquinoline transition metal complexes with pendant phosphino and phosphinyl groups as phosphorescent emitting materials for organic light-emitting devices.

Abstract

Cyclometalated phosphino- and phosphonyl-substituted metal complexes [MLnL1m] (1, HL, HL1 = same or different, preferably, 1-arylpyridine, 1-arylisoquinoline, 3-arylisoquinoline, 2-arylquinoline, etc., substituted in 3'- or 4'-positions by phosphino, phosphinyl or thiophosphinyl groups), useful as triplet-emitting phosphorescent materials for org. light-emitting devices (OLEDs), solar cells etc., featuring enhanced soly., efficiency and lifetime, were prepd. by palladium-catalyzed phosphination of the corresponding 4'- or 5'-bromoaryl N-heterocyclic cyclometalated complexes [M(L-Br)n(L1-Br)m] (2a) with secondary phosphines with subsequent oxidn. or sulfuration of the phosphine function. In an example, reaction of 4.8 mmol of tris[4-bromo-2-(1-isoquinolinyl)phenyl]iridium [2a, HL = HL1 = 1-(3-bromophenyl)isoquinoline] with 14.4 mmol of Ph2PH in the presence of 0.05 mmol of Pd(OAc)2 for 4 days at reflux in 100 mL of N,N-dimethylacetamide gave the phosphino-substituted complex tris[4-(diphenylphosphino)-2-(1-isoquinolinyl)phenyl]iridium [1a, HL = HL1 = 1-(3-diphenylphosphinophenyl)isoquinoline] with 80.7% yield. In another example, oxidn. of 1a (4.4 mmol) by 14.6 mmol of 3-phenyl-2-phenylsulfonyloxaziridine gave the corresponding phosphine oxide, tris[4-(diphenylphosphinyl)-2-(1-isoquinolinyl)phenyl]iridium (1b) with 25.4% yield. In another example, the complex 1b was used for manufg. of test OLED, exhibiting max. efficiency of 8 cd/A, operating voltage of 5.2 V at 100 cd/m2 and lifetime at 1000 cd/m2 of 15,000 h, yielding light of color coordinates CIE(x,y) of 0.67/0.33; the compd. 1b is readily processed by spin-coating process from its soln. in toluene. [on SciFinder(R)]