Luminescent lanthanide complexes with imine ligands and devices made with such complexes

1. A lanthanide compound having Formula III-B below:

Ln(β-enolate) 3 (mono-imine) 2   (III-B)

wherein the mono-imine is selected from 3-cyanopyridine; 2-dimethylaminopyridine; isoquinoline; 4-tertbutyl-pyridine; 4-phenylpyridine; and 2-(2-thienyl)pyridine.

2. The compound of claim 1 wherein Ln is selected from Eu, Tb and Tm.

3. The compound of claim 1 wherein the β-enolate is selected from 2,4-pentanedionate; 1,3-diphenyl- 1,3-propanedionate; 2,2,6,6-tetramethyl-3 ,5-heptanedionate; 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedionate; 7,7-dimethyl-1,1,1,2,2,3,3-heptafluoro-4,6-octanedionate; 1,1,1,5,5,5-hexaflouro-2,4-pentanedionate; 1-phenyl-3-methyl-4-i-butyryl-pyrazolinonate; and 1,1,1,3,5,5,5-heptafluoro-2,4-pentanedionate.

4. An electronic device comprising a photoactive layer, wherein the photoactive layer comprises the lanthanide compound of claim 1 .

5. The device of claim 4 wherein the lanthanide compound is present in an amount of up to about 85% by volume based on the total volume of the photoactive layer.

6. The device of claim 4 wherein the photoactive layer further comprises (b) a charge transport material.

7. The device of claim 6 wherein the charge transport material (b) is a hole transport material selected from N,N′-diphenyl-N,N′-bis(3 -methylphenyl)-[1,1′-biphenyl]-4,4′-diamine and bis[4-(N,N-diethylamino)-2-methylphenyl](4-methylphenyl)methane.

8. The device of claim 6 wherein the charge transport material (b) is an electron and hole transporting material selected from 4,4′-N,N′-dicarbazole biphenyl; chelated oxinoid compounds of aluminum; and cyclometalated iridium complexes with 2-phenylpyridines.

9. The device of claim 4 , further comprising a hole transport layer, wherein the hole transport layer comprises a hole transport material selected from N,N′-diphenyl-N,N′-bis(3 -methylphenyl)-[1,1′-biphenyl]-4,4′-diamine; 1,1-bis[(di-4-tolylamino) phenyl]cyclohexane; N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine; tetrakis-(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine; α-phenyl-4-N,N-diphenylaminostyrene; p-(diethylamino)benzaldehyde diphenylhydrazone; triphenylamine; bis[4-(N,N-diethylamino)-2-methylphenyl](4-methylphenyl)methane; 1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl] pyrazoline; 1,2-trans-bis(9H-carbazol-9-yl)cyclobutane; N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine; porphyrinic compounds; and combinations thereof.

10. The device of claim 4 , further comprising an electron transport layer, wherein the electron transport layer comprises an electron transport material selected from tris(8-hydroxyquinolato)aluminum; 2,9-dimethyl-4,7-diphenyl- 1,10-phenanthroline; 4,7-diphenyl- 1,10-phenanthroline; 2-(4-biphenylyl)-5 -(4-t-butylphenyl)- 1,3,4-oxadiazole; 3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole; and combinations thereof.

11. A lanthanide compound having Formula III-B

Ln(β-enolate) 3 (mono-imine) 2   (III-B)

and having a structure selected from compounds as provided in the below table,

TABLE 1

Compound

Ln

β-enolate

mono-imine

Formula

1-a

Eu

TTFA

4-CNpy

III-B

1-c

Eu

TTFA

isoq

III-B

1-d

Eu

TTFA

4-tbpy

III-B

1-e

Eu

TTFA

4-phpy

III-B

1-g

Tb

Acac

4-CNpy

III-B

1-i

Tb

Acac

isoq

III-B

1-j

Tb

Acac

4-tbpy

III-B

1-k

Tb

Acac

4-phpy

III-B

wherein TTFA is 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedionate; Acac is 2,4-pentanedionate; 4-CNpy is 4-cyanopyridine; isoq is isoquinoline; 4-tbpy is 4-tertbutyl-pyridine; and 4-phpy is 4-phenylpyridine.