# Patent

## Title
Electroluminescent device

## Abstract

Disclosed are electroluminescent devices that comprise organic layers that contain dibenzofuran compounds. The compounds are suitable components of, for example, blue-emitting, durable, organo-electroluminescent layers. The electroluminescent devices may be employed for full color display panels in, for example, mobile phones, televisions and personal computer screens.

## Background
This is a divisional of copending U.S. application Ser. No. 13/164,016, filed on Jun. 20, 2011, which is a divisional of copending U.S. application Ser. No. 11/921,050, filed Nov. 26, 2007, which is a national stage application of international application No. PCT/EP06/062483, filed May 22, 2006.


The present invention relates to electroluminescent devices that comprise organic layers that contain dibenzofuran compounds. The compounds are suitable components of, for example, blue-emitting, durable, organo-electroluminescent layers. The electroluminescent devices may be employed for full color display panels in, for example, mobile phones, televisions and personal computer screens.
H. O. Wirth et al., Die Makromolekulare Chemie 86 (1965) 139-167 describes the synthesis and properties of oxydo-p-oligophenylenes. The following two dibenzofuran compounds are described therein:




JP9151182 discloses dibenzofurandiamine derivatives, which are suitable as a positive hole transporting agent, etc., in electrophotographic photoreceptor, solar cell, electroluminescence element etc. The dibenzofurandiamine derivatives are represented by the following formula




wherein R1 to R5 are each a halogen, a (substituted)alkyl, a (substituted)alkoxy, a (substituted)aryl or (substituted) aralkyl; (a), (b), (c) and (d) are each 0-5; (e) is 0-6. The following compounds are explicitly disclosed in JP9151182:








JP2004311404 discloses compounds having at least one biaryl part structure for use in OLED application. The dimeric dibenzofuran compound shown below is explicitly mentioned.




WO03105538 relates to benzotriazole compounds and their use in OLED application. The dimeric benzotriazole compound shown below is explicitly mentioned.




The compounds shown below are also known:




(J. Chem. Soc. (1962) 5291,





(J. Chem. Soc. (1962) 5291,





(J. Org. Chem. 46 (1981) 851-855),





(Bull. Chem. Soc. Japan 9 (1934) 55), and





(Bull. Chem. Soc. Japan 9 (1934) 55).

Surprisingly, it was found that luminescent devices, which are high durability besides high in the efficiency of electrical energy utilisation and high in luminance, can be obtained if specific benzofuran compounds are used, especially as light emitting substances.
Accordingly, the present invention relates to compounds of the formula




wherein R81, R82, R83, R84, R85, R86, R87, R88, R91, R92, R93, R94, R95, R96, R97, R91′, R92′, R93′, R94′, R95′, R96′ and R97′ are independently of each other H, —OR201, —SR202 and/or —NR203R204, C1-C24alkyl; C1-C24alkyl, which is substituted by E and/or interrupted by D; C2-C18alkenyl, C2-C18alkenyl, which is substituted by E, C3-C8cycloalkyl, C3-C8cycloalkyl, which is substituted by G, aryl, aryl, which is substituted by G, heteroaryl, or heteroaryl, which is substituted by G, silyl, SiR62R63R64, —CN, cyclic ether, —B(OR65)2 and/or halogen, especially fluorine, or

R81 and R82, R82 and R83, R83 and R84, R85 and R86, R86 and R87, R87 and R88, R97 and R96, R96 and R95, R95 and R94, R97′ and R96′, R96′ and R95′, R95′ and/or R94′, and/or two of the groups R91, R92 and R93 or R91′, R92′ and R93′, which are in neighbourhood to each other, together form a group





wherein A41, A42, A43, A44, A45, A46 and A47 are independently of each other H, halogen, hydroxy, C1-C24alkyl, C1-C24alkyl which is substituted by E and/or interrupted by D, C1-C24 perfluoroalkyl, C5-C12cycloalkyl, C5-C12cycloalkyl which is substituted by G and/or interrupted by S—, —O—, or —NR5—, C5-C12cycloalkoxy, C5-C12cycloalkoxy which is substituted by E, C6-C24aryl, C6-C24aryl which is substituted by G, C2-C20heteroaryl, C2-C20heteroaryl which is substituted by G, C2-C24alkenyl, C2-C24alkynyl, C1-C24alkoxy, C1-C24alkoxy which is substituted by E and/or interrupted by D, C7-C25aralkyl, C7-C25aralkyl, which is substituted by G, C7-C25aralkoxy, C7-C25aralkoxy which is substituted by E, or —CO—R8,

M is a bonding group, such as a single (direct) bond, —CO—, —COO—; —S—; —SO—; —SO2—; —O—; C12alkylene, C2-C12alkenylene, or C2-C12alkinylene, which are optionally interrupted by one or more —O—, or —S—; or a group [M1]n, wherein n is an integer 1 to 20, M1 is arylene, or heteroarylene, which is optionally substituted by G, especially naphthylene, biphenylene, styrylene, anthrylene, or pyrenylene, which are optionally substituted by C1-C12alkyl, halogen, —OR201, —SR202 and/or —NR203R204, wherein

R201 is hydrogen, C1-C24alkyl, C1-C24alkyl, which is substituted by E and/or interrupted by D; alkenyl, C3-C6alkenoyl, C3-C8cycloalkyl, or benzoyl, each of which may optionally be substituted by one or more groups C1-C6alkyl, halogen, —OH and/or C1-C4alkoxy; C6-C14aryl, especially phenyl, naphthyl, phenanthryl, anthranyl, or pyrenyl, each of which may optionally be substituted by halogen, —OH, C1-C12alkyl, C1-C12alkoxy, phenoxy, C1-C12alkylsulfanyl, phenylsulfanyl, —N(C1-C12alkyl)2 and/or diphenylamino;

R202 is C1-C24alkyl, C1-C24alkyl, which is substituted by E and/or interrupted by D; C2-C12alkenyl, C1-C8alkanoyl, C2-C12alkenyl, C3-C6alkenoyl; C3-C8cycloalkyl, or benzoyl, each of which may optionally be substituted by one or more groups C1-C6alkyl, halogen, —OH, C1-C4alkoxy or C1-C4alkylsulfanyl;

C6-C14aryl, especially phenyl, naphthyl, phenanthryl, anthranyl, or pyrenyl, each of which may optionally be substituted by halogen, C1-C12alkyl, C1-C12alkoxy, phenyl-C1-C3alkyloxy, phenoxy, C1-C12alkylsulfanyl, phenylsulfanyl, —N(C1-C12alkyl)2, diphenylamino, —(CO)O(C1-C8alkyl), —(CO)—C1-C8alkyl, or (CO)N(C1-C8alkyl)2;

R203 and R204 are independently of each other hydrogen, C1-C24alkyl, C1-C24alkyl, which is substituted by E and/or interrupted by D; C2-C5alkenyl, C3-C8cycloalkyl, or benzoyl, each of which may optionally be substituted by one or more groups C1-C6alkyl, halogen, —OH, or C1-C4alkoxy; phenyl-C1-C3alkyl, C1-C8alkanoyl, C3-C12alkenoyl, C6-C14aryl, especially phenyl naphthyl, phenanthryl anthranyl, or pyrenyl, each of which is optionally substituted by C1-C12alkyl, benzoyl or C1-C12alkoxy; or R203 and R204 together are C2-C8alkylene, or branched C2-C8alkylene optionally interrupted by —O—, —S—, or —NR205— and/or optionally substituted by hydroxyl, C1-C4alkoxy, C2-C4alkanoyloxy, or benzoyloxy, wherein the ring formed by R203 and R204 can optionally be condensed one or two times by phenyl which can be substituted one to three times with C1-C8-alkyl, C1-C8-alkoxy, halogen, or cyano;

R205 is hydrogen, C1-C24alkyl, C1-C24alkyl, which is substituted by E and/or interrupted by D; C2-C5alkenyl, C3-C8cycloalkyl, phenyl-C1-C3alkyl, C1-C8alkanoyl, C3-C12alkenoyl, C8-C14aryl, especially benzoyl; phenyl, naphthyl, phenanthryl, anthranyl, or pyrenyl, each of which is optionally substituted by C1-C12alkyl, benzoyl, or C1-C12alkoxy;

D is —CO—, —COO—, —OCOO—, —S—, —SO—, —SO2—, —O—, —NR5—, —SiR61R62—, —POR5—, —CR63═CR64—, or —C≡C—;

E is halogen, C8-C14aryl, especially phenyl, naphthyl, phenanthryl, anthranyl, or pyrenyl, which may be substituted by —OR5, —SR5, —NR5R6, —SiR62R63R64, wherein R62, R63 and R64 are independently of each other a C1-C8alkyl group, a C6-C24aryl group or a C7-C12aralkyl group, —CN, cyclic ether and/or —B(OR65)2, wherein R65 is hydrogen, C1-C24alkyl, C3-C8cycloalkyl, C7-C24aralkyl, C2-C18alkenyl, C2-C24alkynyl, hydroxy, mercapto, C1-C24alkoxy, C1-C24alkylthio, C8-C38aryl, C2-C38heteroaryl, halogen, especially fluorine, haloalkane, silyl, siloxanyl, and an alicyclic ring formed with adjacent substituents R65; —OR5, —SR5, —NR5R6, —COR8, —COOR7, —CONR5R6, —CN, halogen, silyl, C1-C18alkyl, or heteroaryl,
G is E, or C1-C18alkyl, wherein R5 and R6 are independently of each other H, C8-C18aryl; C8-C18aryl which is substituted by C1-C18alkyl, C1-C18alkoxy, or silyl; C1-C18alkyl or C1-C18alkyl which is interrupted by —O—; or
R5 and R6 together form a five or six membered ring, in particular




R7 is H, C8-C18aryl, C7-C12alkylaryl, which are optionally substituted by C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl; or C1-C18alkyl which is interrupted by —O—;

R8 is C8-C18aryl; C8-C18aryl which is substituted by C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl, C7-C12alkylaryl, or C1-C18alkyl which is interrupted by —O—;

R61 and R62 are independently of each other C8-C18aryl; C8-C18aryl which is substituted by C1-C18alkyl, C1-C18alkoxy; or C1-C18alkyl which is interrupted by —O—, and

R63 and R64 are independently of each other H, C8-C18aryl; C8-C18aryl which is substituted by C1-C18alkyl, C1-C18alkoxy; or C1-C18alkyl which is interrupted by —O—; with the proviso that at least one of R81, R82, R83, R84, R85, R86, R87 and R88 is different from H, —OR201, —SR202 and C1-C24alkyl; and the further proviso that the following compounds are excluded:











Preferably, the compound or compounds of the present invention emit light below about 520 nm, in particular between about 380 nm and about 520 nm.
The compound or compounds of the present invention have especially a NTSC coordinate of between about (0.12, 0.05) and about (0.16, 0.10), very especially a NTSC coordinate of about (0.14, 0.08).
The compound or compounds of the present invention have a melting point above about 150° C., preferably above about 200° C. and most preferred above about 250° C.
To obtain organic layers of this invention with the proper Tg, or glass transition temperature, it is advantageous that the present organic compounds have a glass transition temperature greater than about 100° C., for example greater than about 110° C., for example greater than about 120° C., for instance greater than about 130° C.
In one embodiment of the present invention compounds of formula I, or II are preferred, wherein at least one of the groups R81, R82, R83, R84, R85, R86, R87, R88, R91, R92, R93, R94, R95, R96, R97, R91′, R92′, R93′, R84′, R95′, R96′ and R97′ is a C7-C30aryl group, especially a polycyclic C8-C30aryl group. Compounds of formula I, or II are even more preferred, wherein at least two of the groups R81, R82, R83, R84, R85, R86, R87, R88, R91, R92, R93, R94, R95, R96, R97, R91′, R92′, R93′, R94′, R95′, R96′ and R97′ are a C7-C30aryl group, especially a polycyclic C8-C30aryl group.
In a further embodiment of the present invention compounds of formula are preferred, wherein M is a single bond, —CO—, —COO—, —S—, —SO—, —SO2—, —O—,




especially





especially





especially





especially





especially





especially





wherein

n1, n2, n3, n4, n5, n6 and n7 are integers of 1 to 10, in particular 1 to 3,

A6 and A7 are independently of each other H, C1-C18alkyl, C1-C18alkyl which is substituted by E′ and/or interrupted by D′, C6-C24aryl, C6-C24aryl which is substituted by G′, C2-C20heteroaryl, C2-C20heteroaryl which is substituted by G′, C2-C18alkenyl, C2-C18alkynyl, C1-C18alkoxy, C1-C18alkoxy which is substituted by E′ and/or interrupted by D′, C7-C25aralkyl, or —CO-A28,

A8 is C1-C18alkyl, C1-C18alkyl which is substituted by E′ and/or interrupted by D′, C6-C24 aryl, or C7-C25aralkyl,

A9 and A10 are independently of each other C1-C18alkyl, C1-C18alkyl which is substituted by E′ and/or interrupted by D′, C6-C24aryl, C6-C24aryl which is substituted by G′, C2-C20heteroaryl, C2-C20heteroaryl which is substituted by G′, C2-C18alkenyl, C2-C18alkynyl, C1-C18alkoxy, C1-C18alkoxy which is substituted by E′ and/or interrupted by D′, or C7-C25aralkyl, or

A9 and A10 form a ring, especially a five- or six-membered ring, which can optionally be substituted by one or more C1-C18 alkyl groups;

A14 and A15 are independently of each other H, C1-C18alkyl, C1-C18alkyl which is substituted by E′ and/or interrupted by D′, C6-C24aryl, C6-C24aryl which is substituted by G′, C2-C20heteroaryl, or C2-C20heteroaryl which is substituted by G′,

D′ is —CO—; —COO—; —S—; —SO—; —SO2—; —O—; —NA25-; —SiA30A31-; —POA32-; —CA23=CA24-; or —C≡C—; and

E′ is —OA29; —SA29; —NA25A26; —COA28; —COOA27; —CONA26A26; —CN; —OCOOA27; or halogen; G′ is E′, or C1-C18alkyl; wherein A23, A24, A25 and A26 are independently of each other H; C6-C18aryl; C6-C18aryl which is substituted by C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl, or C1-C18alkyl which is interrupted by —O—; or A25 and A26 together form a five or six membered ring, in particular





A27 and A28 are independently of each other H; C6-C18aryl; C6-C18aryl which is substituted by C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl, or C1-C18alkyl which is interrupted by —O—,

A29 is H; C6-C18aryl; C6-C18aryl, which is substituted by C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl; or C1-C18alkyl which is interrupted by —O—,

A30 and A31 are independently of each other C1-C18alkyl, C6-C18aryl, or C6-C18aryl, which is substituted by C1-C18alkyl, and

A32 is C1-C18alkyl, C6-C18aryl, or C6-C18aryl, which is substituted by C1-C18alkyl.

Preferably, A6 and A7 are independently of each other H, C1-C18alkyl, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, sec-butyl, t-butyl, 2-methylbutyl, n-pentyl, isopentyl, n-hexyl, 2-ethylhexyl, or n-heptyl, C1-C18alkyl which is substituted by E′ and/or interrupted by D′, such as —CH2OCH3, —CH2OCH2CH3, —CH2OCH2CH2OCH3, or —CH2OCH2CH2OCH2CH3, C6-C24aryl, such as phenyl, naphthyl, or biphenyl, C6-C24aryl which is substituted by G′, such as —C6H4OCH3, —C6H4OCH2CH3, —C6H3(OCH3)2, or —C6H3(OCH2CH3)2, —C6H4CH3, —C6H3(CH3)2, —C6H2(CH3)3, or —C6H4tBu.
A8 is preferably H, C1-C18alkyl, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, sec-butyl, t-butyl, 2-methylbutyl, n-pentyl, isopentyl, n-hexyl, 2-ethylhexyl, n-heptyl, or C6-C24aryl, such as phenyl, naphthyl, or biphenyl.
Preferably, A9 and A10 are independently of each other H, C1-C18alkyl, such as n-butyl, sec-butyl, hexyl, octyl, or 2-ethyl-hexyl, C1-C18alkyl which is substituted by E′ and/or interrupted by D′, such as —CH2(OCH2CH2)wOCH3, w=1, 2, 3, or 4, C6-C24aryl, such as phenyl, naphthyl, or biphenyl, C6-C24aryl which is substituted by G′, such as —C6H4OCH3, —C6H4OCH2CH3, —C6H3(OCH3)2, —C6H3(OCH2CH3)2, —C6H4CH3, —C6H3(CH3)2, —C6H2(CH3)3, or —C6H4tBu, or A9 and A10 together form a 4 to 8 membered ring, especially a 5 or 6 membered ring, such as cyclohexyl, or cyclopentyl.
Preferably, A14 and A15 are independently of each other H, C1-C18alkyl, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, or sec-butyl, or C6-C24aryl, such as phenyl, naphthyl, or biphenyl.
D′ is preferably —CO—, —COO—, —S—, —SO—, —SO2—, —O—, —NA25-, wherein A25 is C1-C18alkyl, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, or sec-butyl, or C6-C24aryl, such as phenyl, naphthyl, or biphenyl.
E′ is preferably —OA29; —SA29; —NA25A25; —COA28; —COOA27; —CONA25A25; or —CN; wherein A25, A27, A28 and A29 are independently of each other C1-C18alkyl, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, sec-butyl, hexyl, octyl, or 2-ethyl-hexyl, or C6-C24 aryl, such as phenyl, naphthyl, or biphenyl.
Among the above-mentioned groups M the following groups are preferred:







Examples of especially preferred groups M are:





wherein A8 and A9 are independently of each other C1-C18alkyl, or cyclohexan;





wherein A6 and A7 are independently of each other H, or C1-C18alkyl; or





Groups M having a polycyclic C8-C30arylen group, or a polycyclic C4-C26heteroarylen group, wherein polycyclic ring system comprises at least 8 atoms, are preferred,





are most preferred.

Among the compounds of formula II compounds of formula




are preferred.

Compounds of formula




are even more preferred, wherein R95 and R95′ are independently of each other C1-C24alkyl, or C6-C18aryl, especially phenyl, naphthyl, phenanthryl, anthranyl, or pyrenyl, which may be substituted by one, or more C1-C8alkyl, or C1-C8alkoxy groups, such as a group of formula





especially





wherein

R41, R41′, R42 and R42′ are independently of each other is hydrogen, C1-C8alkyl, or C1-C8alkoxy,

R45′ is hydrogen, phenyl, or 1-naphthyl, which can be substituted by one, or more C1-C8alkyl, or C1-C8alkoxy groups; or C1-C8alkyl, or C1-C8alkoxy.

In another embodiment compounds of formula IIb are preferred, wherein M is a single bond,
R96 and R96′ are a group




especially





and R91, R92, R93, R94, R95, R96, R97, R91′, R92′, R93′, R94′, R95′, R96′ and R97′ are hydrogen.

Examples of especially preferred compounds are:










In further preferred embodiment of the present invention at least one, preferably two of the groups R81, R82, R83, R84, R85, R86, R87, R88, R91, R92, R93, R94, R95, R96, R97, R91′, R92′, R93′, R94′, R95′, R96′ and R97′ are a group




wherein A14′ and A15′ are independently of each other H, C1-C18alkyl, C1-C18alkyl which is substituted by E and/or interrupted by D, C6-C24aryl, C6-C24aryl which is substituted by G, C2-C20heteroaryl, or C2-C20heteroaryl which is substituted by G, and A16′ is H, C1-C18alkyl, C1-C18alkyl which is substituted by E and/or interrupted by D, C6-C24aryl, C6-C24aryl which is substituted by G, C2-C20heteroaryl, or C2-C20heteroaryl which is substituted by G; or a polycyclic aryl group, especially pentalenyl, indenyl, azulenyl, naphthyl, biphenylenyl, as-indacenyl, s-indacenyl, acenaphthylenyl, fluorenyl, phenanthryl, anthracenyl, fluoranthenyl, acephenanthrylenyl, aceanthrylenyl, triphenylenyl, pyrenyl, chrysenyl, naphthacenyl, picenyl, perylenyl, pentacenyl, pentaphenyl, hexacenyl, or hexaphenyl, which can optionally be substituted by G, wherein D, E and G are as defined above.

Examples of particularly preferred groups are:




wherein R300 is C1-C8alkyl, phenyl, which can be substituted by one, or more C1-C8alkyl, or C1-C8alkoxy groups, R14 is hydrogen, C1-C8alkyl, phenyl, or 1-naphthyl, which can be substituted by one, or more C1-C8alkyl, or C1-C8alkoxy groups; or C1-C8alkoxy, and

R18 and R19 are independently of each other C1-C8alkyl, or cyclohexan.

Compounds of formula Ia, Ib and Ic are preferred, wherein R82, R87, R83, R88, R83′ and R86′ are independently of each other one of the above groups. R82 and R87, R83 and R86, R83′ and R86′ can be the same or different.
In a further preferred embodiment of the present invention at least one, especially two of the groups R81, R82, R83, R84, R85, R86, R87, R88, R91, R92, R93, R94, R95, R96, R97, R91′, R92′, R93′, R94′, R95′, R98′ and R97′ are independently of each other a group the formula —(W1)a—(W2)b—W3(Y1), wherein
a and b are 0, or 1,
W1 and W2 are independently of each other a group of formula




especially





and

W3 is a group of formula





especially





wherein

R11, R11′, R12, R12′, R13, R13′, R15, R15′, R16, R16′, R17, R17′, R41, R41′, R42, R42′, R44, R44′, R45, R45′, R46, R46′, R47 and R47′ are independently of each other H, E, silyl, such as tri(C1-C8alkyl)silyl, C6-C18aryl; C6-C18aryl which is substituted by G; C1-C18alkyl; C1-C18alkyl which is substituted by E and/or interrupted by D; C1-C18alkoxy; or C1-C18alkoxy which is substituted by E and/or interrupted by D; C7-C18aralkyl; or C7-C18aralkyl which is substituted by G;

R14 is H, silyl, such as tri(C1-C8alkyl)silyl, C1-C18alkyl; or C1-C18alkyl which is substituted by E and/or interrupted by D; C1-C18alkoxy; or C1-C18alkoxy which is substituted by E and/or interrupted by D;





R18 and R19 are independently of each other C1-C18alkyl; C1-C18alkoxy, C6-C18aryl; C7-C18aralkyl; or

R18 and R19 together form a ring especially a five- or six-membered ring, which can optionally be substituted by C1-C8alkyl,

R21, R22, R23, R24, R25, R26 and R27 are independently of each other H, E, C1-C18alkyl; C1-C18alkyl which is substituted by E and/or interrupted by D; C7-C18aralkyl; C7-C18aralkyl which is substituted by G; or

W3 is a group of formula











wherein

R315 and R316 are independently of each other a hydrogen atom, a C1-C18alkyl group, a C1-C18alkoxy group, a group of formula





wherein R318, R319 and R320 independently from each other stand for hydrogen, C1-C8-alkyl, C1-C8-alkoxy, or phenyl, and

R317 stands for is a hydrogen atom, a C1-C25alkyl group, which might be interrupted by —O—, a cycloalkyl group, a C7-C18aralkyl group, a C6-C18aryl group, or a heterocyclic group, which may be substituted by G; wherein

D is —CO—, —COO—, —OCOO—, —S—, —SO—, —SO2—, —O—, —NR8—, SiR61R62—, —POR5—, —CR63═CR64—, or —C≡C—;

E is —OR5, —SR5, —NR5R6, —COR8, —COOR7, —OCOOR7, —CONR5R6, —CN, or halogen;

G is E, or C1-C18alkyl; wherein R5 and R6 are independently of each other C6-C18aryl; C6-C18aryl which is substituted by C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl, or C1-C18alkyl which is interrupted by —O—; or

R5 and R6 together form a five or six membered ring, in particular





R7 is C7-C12alkylaryl; C1-C18alkyl; or C1-C18alkyl which is interrupted by —O—;

R8 is C6-C18aryl; C6-C18aryl which is substituted by C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl; C7-C12alkylaryl, or C1-C18alkyl which is interrupted by —O—;

R61 and R62 are independently of each other C6-C18aryl; C6-C18aryl which is substituted by C1-C18alkyl, or C1-C18alkoxy; or C1-C18alkyl which is interrupted by —O—, and

R63 and R64 are independently of each other H, C6-C18aryl; C6-C18aryl which is substituted by C1-C18alkyl, C1-C18alkoxy; or C1-C18alkyl which is interrupted by —O—.

If W3 is derived from a heteroaromatic group, it is preferably a group of formula




wherein R317 is C1-C18alkyl.

Examples of preferred groups W1 and W2 are




wherein R11 is hydrogen, or C1-C8alkyl.

Examples of preferred groups W3 are




wherein R14, R41′ and R44 are hydrogen, phenyl, tri(C1-C8alkyl)silyl, or C1-C8alkyl, R18 and R19 are independently of each other C1-C8alkyl, or cyclohexan.

Examples of preferred groups —(W1)a—(W2)b—W3 are




wherein R11, R14, R18 and R19 are independently of each other hydrogen, or C1-C8alkyl.

Among the compounds of formula I compounds of formula




are more preferred, wherein R82, R83, R86 and R87 are independently of each other a group the formula —(W1)a—(W2)b—W3. R82, R83, R86 and R87 can be different, but are preferably the same; and R81 and R88 are as defined above.

In a preferred embodiment of the present invention at least one, preferably two of the substituents R82, R83, R86, R87, R81 and R88 are




especially





Compounds of formula Ia are even more preferred, wherein R83 and R86 are




especially





In a further preferred embodiment of the present invention compounds of formula




are preferred,

wherein R81, R83 and R83 a group the formula —(W2)—W3, wherein

W2 is a group





wherein R13′ and R17 are independently of each other C1-C18alkyl, or C1-C18alkoxy,

W3 is a group




A further preferred embodiment of the present invention is directed to compounds of formula Ia and Ib, wherein at least R82 and at least R83 are a group of formula




wherein A14′ and A15′ are independently of each other H, C1-C18alkyl, C6-C24aryl, or phenyl, which is substituted by one, or more C1-C8alkyl, or C1-C8alkoxy groups and the other, and R87 and R86 are a group of formula





or a group of formula —(W1)a—(W2)b—W3.

A further preferred embodiment of the present invention is directed to compounds of formula




wherein R83′ and R86′ are independently of each other H, C1-C18alkyl,





wherein R14 is hydrogen, phenyl, tri(C1-C8alkyl)silyl, or C1-C8alkyl, R18 and R19 are independently of each other C1-C8alkyl, or cyclohexan.

Examples of especially preferred compounds are given below:




















































Particularly suitable dibenzo-, dinaphthofurans are compounds A-1, A-2, A-4, A-5, A-10, A-11, A-16, A-19, B-1 and B-2.
In another preferred embodiment at least one, preferably two of the substituents R81, R82, R83, R84, R85, R86, R87, R88, R91, R92, R93, R94, R95, R96, R97, R91′, R92′, R93′, R94′, R95′, R96′ and R97′ are independently of each other a group of the formula —W1—(W2)b—W3(Y2), wherein b is 0, or, 1, W1 and W2 are as defined above and are preferably independently of each other a group of formula




especially





W3 is a group of formula —NR70R71, wherein R70 and R71 are independently of each other a group of formula





wherein R72, R73 and R74 are independently of each other hydrogen, C1-C8alkyl, a hydroxyl group, a mercapto group, C1-C8alkoxy, C1-C8alkylthio, halogen, halo-C1-C8alkyl, a cyano group, an aldehyde group, a ketone group, a carboxyl group, an ester group, a carbamoyl group, an amino group, a nitro group, a silyl group or a siloxanyl group, or R70 and R71 together with the nitrogen atom to which they are bonded form a five or six membered heterocyclic ring, such as





which can be condensed by one or two optionally substituted phenyl groups, such as





wherein R216 and R217 independently from each other stands for hydrogen, C1-C8alkyl, C1-C8alkoxy, or phenyl, and

X1 stands for hydrogen, or C1-C8alkyl;

R75, R76, R77 and R78 are independently of each other H, E, C6-C18aryl; C6-C18aryl which is substituted by E; C1-C18alkyl; C1-C18alkyl which is substituted by G and/or interrupted by D; C7-C18aralkyl; or C7-C18aralkyl which is substituted by E; wherein D, E, G, R11, R11′, R12′, R16, R16′, R17, R17′, R18, R19, R30, R31, R32 and R33 are as defined above, and R30′, R31′, R32′ and R33′ independently of each other have the meaning of R30.

If R70 and R71 are independently of each other a group of formula




b is preferably 1.

In said embodiment groups of the formula —W1—(W2)b—W3 are more preferred, wherein b is 0, or 1,
W1 and W2 are independently of each other a group of formula




W3 is a group of formula





or —NR70R71, wherein R70 and R71 are independently of each other a group of formula





wherein R72 is C1-18alkyl.

In said embodiment of the present invention compounds of formula Ia and Ib are preferred, wherein R82 and R87 and R83 and R86 are independently of each other a group of formula —(W2)b—W3. The groups —(W2)b—W3 can be different, but are preferably the same.
Examples of preferred compounds are given below:




In another preferred embodiment the present invention is directed to compounds of formula I wherein at least one of R81, R82, R83, R84, R85, R86, R87 and R88 is a group Y1 and at least one of R81, R82, R83, R84, R85, R86, R87 and R88 is a group Y2.
In said embodiment compounds of formula Ia are preferred, wherein R81 is H, R88 is Y2 and R83 and R86 are Y1; or R81 and R88 are H, R83 is Y2 and R86 are Y1.




Examples of preferred compounds are given below:




The present benzofuran compounds show a high solid state fluorescence in the desired wavelength range and can be prepared according to or analogous to known procedures (see, for example, WO99/47474, WO2004039786 and WO2004077885).
The benzofuran compounds of the present invention of the formula:




wherein W3 is as defined above,

can, for example, be prepared according to a process, which comprises reacting a derivative of formula





wherein R100 stands for halogen such as chloro or bromo, preferably bromo, or E having the meaning of





wherein a is 2 or 3,

with boronic acid derivative E-W3, or—in case R100 is not halogen -Hal-W3,

wherein Hal stands for halogen, preferably for bromo, in the presence of an allylpalladium catalyst of the μ-halo(triisopropylphosphine)(η3-allyl)palladium(II) type (see for example WO99/47474).

Preferably, the reaction is carried out in the presence of an organic solvent, such as an aromatic hydrocarbon or a usual polar organic solvent, such as benzene, toluene, xylene, tetrahydrofurane, or dioxane, or mixtures thereof, most preferred toluene. Usually, the amount of the solvent is chosen in the range of from 1 to 10 l per mol of boronic acid derivative. Also preferred, the reaction is carried out under an inert atmosphere such as nitrogen, or argon.
Further, it is preferred to carry out the reaction in the presence of an aqueous base, such as an alkali metal hydroxide or carbonate such as NaOH, KOH, Na2CO3, K2CO3, Cs2CO3 and the like, preferably an aqueous K2CO3 solution is chosen. Usually, the molar ratio of the base to compound III is chosen in the range of from 0.5:1 to 50:1.
Generally, the reaction temperature is chosen in the range of from 40 to 180° C., preferably under reflux conditions.
Preferred, the reaction time is chosen in the range of from 1 to 80 hours, more preferably from 20 to 72 hours.
In a preferred embodiment a usual catalyst for coupling reactions or for polycondensation reactions is used, preferably Pd-based catalyst such as known tetrakis(triarylphosphonium)-palladium, preferably (Ph3P)4Pd and derivatives thereof. Usually, the catalyst is added in a molar ratio from inventive DPP polymer to the catalyst in the range of from 100:1 to 10:1, preferably from 50:1 to 30:1.
Also preferred, the catalyst is added as in solution or suspension. Preferably, an appropriate organic solvent such as the ones described above, preferably benzene, toluene, xylene, THF, dioxane, more preferably toluene, or mixtures thereof, is used. The amount of solvent usually is chosen in the range of from 1 to 10 l per mol of boronic acid derivative.
The obtained inventive polymer can be isolated by well-known methods. Preferably, after cooling down the reaction mixture to room temperature, it is poured into acetone and the obtained precipitation is filtered off, washed and dried.
C1-C18Alkyl is a branched or unbranched radical such as for example methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, 2-ethylbutyl, n-pentyl, isopentyl, 1-methylpentyl, 1,3-dimethyl-butyl, n-hexyl, 1-methylhexyl, n-heptyl, isoheptyl, 1,1,3,3-tetramethylbutyl, 1-methylheptyl, 3-methyl-heptyl, n-octyl, 2-ethylhexyl, 1,1,3-trimethylhexyl, 1,1,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1-methylundecyl, dodecyl, 1,1,3,3,5,5-hexamethylhexyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, or octadecyl.
C1-C18Alkoxy radicals are straight-chain or branched alkoxy radicals, e.g. methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, amyloxy, isoamyloxy or tert-amyloxy, heptyloxy, octyloxy, isooctyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tetradecyloxy, pentadecyloxy, hexadecyloxy, heptadecyloxy and octadecyloxy.
C2-C18Alkenyl radicals are straight-chain or branched alkenyl radicals, such as e.g. vinyl, allyl, methallyl, isopropenyl, 2-butenyl, 3-butenyl, isobutenyl, n-penta-2,4-dienyl, 3-methyl-but-2-enyl, n-oct-2-enyl, n-dodec-2-enyl, isododecenyl, n-dodec-2-enyl or n-octadec-4-enyl.
C2-24Alkynyl is straight-chain or branched and preferably C2-8alkynyl, which may be unsubstituted or substituted, such as, for example, ethynyl, 1-propyn-3-yl, 1-butyn-4-yl, 1-pentyn-5-yl, 2-methyl-3-butyn-2-yl, 1,4-pentadiyn-3-yl, 1,3-pentadiyn-5-yl, 1-hexyn-6-yl, cis-3-methyl-2-penten-4-yn-1-yl, trans-3-methyl-2-penten-4-yn-1-yl, 1,3-hexadiyn-5-yl, 1-octyn-8-yl, 1-nonyn-9-yl, 1-decyn-10-yl or 1-tetracosyn-24-yl.
C4-C18cycloalkyl is preferably C5-C12cycloalkyl, such as, for example, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cyclododecyl. Cyclohexyl and cyclododecyl are most preferred.
The term “aryl group” is typically C6-C30aryl, such as phenyl, indenyl, azulenyl, naphthyl, biphenyl, terphenylyl or quadphenylyl, as-indacenyl, s-indacenyl, acenaphthylenyl, phenanthryl, fluoranthenyl, triphenlenyl, chrysenyl, naphthacen, picenyl, perylenyl, pentaphenyl, hexacenyl, pyrenyl, or anthracenyl, preferably phenyl, 1-naphthyl, 2-naphthyl, 9-phenanthryl, 2- or 9-fluorenyl, 3- or 4-biphenyl, which may be unsubstituted or substituted. Examples of C6-C18aryl are phenyl, 1-naphthyl, 2-naphthyl, 3- or 4-biphenyl, 9-phenanthryl, 2- or 9-fluorenyl, which may be unsubstituted or substituted.
C7-C24aralkyl radicals are preferably C7-C18aralkyl radicals, which may be substituted, such as, for example, benzyl, 2-benzyl-2-propyl, β-phenyl-ethyl, α,α-dimethylbenzyl, ω-phenyl-butyl, ω,ω-dimethyl-ω-phenyl-butyl, ω-phenyl-dodecyl, ω-phenyl-octadecyl, ω-phenyl-eicosyl or ω-phenyl-docosyl, preferably C7-C18aralkyl such as benzyl, 2-benzyl-2-propyl, β-phenyl-ethyl, α,α-dimethylbenzyl, ω-phenyl-butyl, ω,ω-dimethyl-ω-phenyl-butyl, ω-phenyl-dodecyl or ω-phenyl-octadecyl, and particularly preferred C7-C12aralkyl such as benzyl, 2-benzyl-2-propyl, β-phenyl-ethyl, α,α-dimethylbenzyl, ω-phenyl-butyl, or ω,ω-dimethyl-ω-phenyl-butyl, in which both the aliphatic hydrocarbon group and aromatic hydrocarbon group may be unsubstituted or substituted.
C7-C12alkylaryl is, for example, a phenyl group substituted with one, two or three C1-C6alkyl groups, such as, for example, 2-, 3-, or 4-methylphenyl, 2-, 3-, or 4-ethylphenyl, 3-, or 4-isopropylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, or 3,4,5-trimethylphenyl.
The term “heteroaryl group”, especially C2-C30heteroaryl, is a ring, wherein nitrogen, oxygen or sulfur are the possible hetero atoms, and is typically an unsaturated heterocyclic radical with five to 18 atoms having at least six conjugated π-electrons such as thienyl, benzo[b]thienyl, dibenzo[b,d]thienyl, thianthrenyl, furyl, furfuryl, 2H-pyranyl, benzofuranyl, isobenzofuranyl, 2H-chromenyl, xanthenyl, dibenzofuranyl, phenoxythienyl, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, bipyridyl, triazinyl, pyrimidinyl, pyrazinyl, 1H-pyrrolizinyl, isoindolyl, pyridazinyl, indolizinyl, isoindolyl, indolyl, 3H-indolyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinnolinyl, indazolyl, purinyl, quinolizinyl, chinolyl, isochinolyl, phthalazinyl, naphthyridinyl, chinoxalinyl, chinazolinyl, cinnolinyl, pteridinyl, carbazolyl, 4aH-carbazolyl, carbolinyl, benzotriazolyl, benzoxazolyl, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl, isoxazolyl, furazanyl or phenoxazinyl, preferably the above-mentioned mono- or bicyclic heterocyclic radicals, which may be unsubstituted or substituted.
Halogen is fluorine, chlorine, bromine and iodine.
The terms “haloalkyl” mean groups given by partially or wholly substituting the above-mentioned alkyl group, with halogen, such as trifluoromethyl etc. The “aldehyde group, ketone group, ester group, carbamoyl group and amino group” include those substituted by an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or a heterocyclic group, wherein the alkyl group, the cycloalkyl group, the aryl group, the aralkyl group and the heterocyclic group may be unsubstituted or substituted. The term “silyl group” means a group of formula —SiR62R63R64, wherein R62, R63 and R64 are independently of each other a C1-C8alkyl group, in particular a C1-C4alkyl group, a C6-C24aryl group or a C7-C12aralkyl group, such as a trimethylsilyl group. The term “siloxanyl group” means a group of formula —O—SiR62R63R64, wherein R62, R63 and R64 are as defined above, such as a trimethylsiloxanyl group.
Possible substituents of the above-mentioned groups are C1-C8alkyl, a hydroxyl group, a mercapto group, C1-C8alkoxy, C1-C8alkylthio, halogen, halo-C1-C8alkyl, a cyano group, an aldehyde group, a ketone group, a carboxyl group, an ester group, a carbamoyl group, an amino group, a nitro group or a silyl group.
As described above, the aforementioned radicals may be substituted by E and/or, if desired, interrupted by D. Interruptions are of course possible only in the case of radicals containing at least 2 carbon atoms connected to one another by single bonds; C6-C18aryl is not interrupted; interrupted arylalkyl or alkylaryl contains the unit D in the alkyl moiety. C1-C18alkyl substituted by one or more E and/or interrupted by one or more units D is, for example, (CH2CH2O)n—Rx, where n′ is a number from the range 1-9 and Rx is H or C1-C10alkyl or C2-C10alkanoyl (e.g. CO—CH(C2H5)C4H9), CH2—CH(ORy′)—CH2—O—Ry, where Ry is C1-C18alkyl, C5-C12cycloalkyl, phenyl, C7-C15-phenylalkyl, and Ry′ embraces the same definitions as Ry or is H; C1-C8alkylene-COO—Rz, e.g. CH2COORz, CH(CH3)COORz, C(CH3)2COORz, where Rz is H, C1-C18alkyl, (CH2CH2O)1-9—Rx, and Rx embraces the definitions indicated above;
CH2CH2—O—CO—CH═CH2; CH2CH(OH)CH2—O—CO—C(CH3)═CH2.
The electroluminescent devices may be employed for full color display panels in, for example, mobile phones, televisions and personal computer screens.
The electroluminescent devices of the present invention are otherwise designed as is known in the art, for example as described in U.S. Pat. Nos. 5,518,824, 6,225,467, 6,280,859, 5,629,389, 5,486,406, 5,104,740, 5,116,708 and 6,057,048, the relevant disclosures of which are hereby incorporated by reference.
For example, organic EL devices contain one or more layers such as:
substrate; base electrode; hole-injecting layer; hole transporting layer; emitter layer; electron-transporting layer; electron-injecting layer; top electrode; contacts and encapsulation.
This structure is a general case and may have additional layers or may be simplified by omitting layers so that one layer performs a plurality of tasks. For instance, the simplest organic EL device consists of two electrodes which sandwich an organic layer that performs all functions, including the function of light emission.
A preferred EL device comprises in this order:
(a) an anode,
(b) a hole injecting layer and/or a hole transporting layer,
(c) a light-emitting layer,
(d) optionally an electron transporting layer and
(e) a cathode.
The benzofuran compounds of the present invention can, in principal be used for any organic layer, such as, for example, hole transporting layer, light emitting layer, or electron transporting layer, but are preferably used as the light emitting material in the light emitting layer, optionally as a host or guest component, or electron transporting layer.
In particular, the present organic compounds function as light emitters and are contained in the light emission layer or form the light-emitting layer.
The light emitting compounds of this invention exhibit intense fluorescence in the solid state and have excellent electric-field-applied light emission characteristics. Further, the light emitting compounds of this invention are excellent in the injection of holes from a metal electrode and the transportation of holes; as well as being excellent in the injection of electrons from a metal electrode and the transportation of electrons. They are effectively used as light emitting materials and may be used in combination with other hole transporting materials, other electron transporting materials or other dopants.
The organic compounds of the present invention form uniform thin films. The light emitting layers may therefore be formed of the present organic compounds alone.
Alternatively, the light-emitting layer may contain a known light-emitting material, a known dopant, a known hole transporting material or a known electron transporting material as required. In the organic EL device, a decrease in the brightness and life caused by quenching can be prevented by forming it as a multi-layered structure. The light-emitting material, a dopant, a hole-injecting material and an electron-injecting material may be used in combination as required. Further, a dopant can improve the light emission brightness and the light emission efficiency, and can attain the red or blue light emission. Further, each of the hole transporting zone, the light-emitting layer and the electron transporting zone may have the layer structure of at least two layers. In the hole transporting zone in this case, a layer to which holes are injected from an electrode is called “hole-injecting layer”, and a layer which receives holes from the hole-injecting layer and transport the holes to a light-emitting layer is called “hole transporting layer”. In the electron transporting zone, a layer to which electrons are injected from an electrode is called “electron-injecting layer”, and a layer which receives electrons from the electron-injecting layer and transports the electrons to a light-emitting layer is called “electron transporting layer”. These layers are selected and used depending upon factors such as the energy level and heat resistance of materials and adhesion to an organic layer or metal electrode.
The light-emitting material or the dopant which may be used in the light-emitting layer together with the organic compounds of the present invention includes for example anthracene, naphthalene, phenanthrene, pyrene, tetracene, coronene, chrysene, fluorescein, perylene, phthaloperylene, naphthaloperylene, perinone, phthaloperinone, naphthaloperinone, diphenylbutadiene, tetraphenylbutadiene, coumarine, oxadiazole, aldazine, bisbenzoxazoline, bisstyryl, pyrazine, cyclopentadiene, quinoline metal complex, aminoquinoline metal complex, benzoquinoline metal complex, imine, diphenylethylene, vinyl anthracene, diaminocarbazole, pyran, thiopyran, polymethine, merocyanine, an imidazole-chelated oxynoid compound, quinacridone, rubrene, and fluorescent dyestuffs for a dyestuff laser or for brightening.
It is also possible to use the compounds of the present invention with phosphorescent materials as a dopant in the light-emitting layer. Examples of the phosphorescent materials are, for example, metal complexes of Ir, Pt, Eu, Ru, Rh, Pd, Ag, Re, Os and Au and are described, for example, in JP2005-11804 and WO2004/034751.
Examples of typical structures of the metal complex are shown below:

























In that case the electroluminescent device may comprise in this order
(a) an anode, such as, for example, ITO,
(b1) a hole injecting layer, such as, for example, CuPc,
(b2) a hole transporting layer, such as, for example, such as, for example, N,N′-Di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPD), or TCTA,
(c) a light-emitting layer, comprising a phosphorescent compound and a dibenzofuran compound of the present invention, especially a compound A-1 to A-66, B-1 to B-18, C-1 and C-2.
a positive hole inhibiting layer, such as, for example, BCP, or BAlq,
(d) an electron transporting layer, such as, for example, Alq3, and
an inorganic compound layer, such as, for example, LiF,
(e) a cathode, such as, for example, Al.
If the dibenzofuran compounds of the present invention are used as host together with guest compounds, such, as for example, 2,5,8,11-tetra-t-butylperylene (Jiaumin Shi Ching W. Tang, Appl. Phys. Lett. 80, 3201 (2002), or the compounds, described, for example, in WO03/105538, such as, for example,




the electroluminescent device may comprise in this order

(a) an anode, such as, for example, ITO,

(b1) a hole injecting layer, such as, for example, CuPc,

(b2) a hole transporting layer, such as, for example, NPD, or TCTA,

(c) a light-emitting layer, comprising a fluorescent guest compound and a dibenzofuran host compound of the present invention, especially a compound A-1 to A-66, B-1 to B-18, C-1 and C-2, optionally a positive hole inhibiting layer, such as, for example, BCP,

(d) an electron transporting layer, such as, for example, Alq3, or TPBI and an inorganic compound layer, such as, for example, LiF,

(e) a cathode, such as, for example, Al.

The weight ratio of compound of the formula I to the dopant in general 50:50 to 99.99:0.01, preferably 90:10 to 99.99:0.01, more preferably 95:5 to 99.9:0.1. If the guest is a phosphorescent compound, its concentration is normally 5-10%.
Accordingly, the present invention also relates to compositions comprising a compound of the present invention.
The compounds of the present invention and the above compound or compounds that can be used in a light-emitting layer may be used in any mixing ratio for forming a light-emitting layer. That is, the organic compounds of the present invention may provide a main component for forming a light-emitting layer, or they may be a doping material in another main material, depending upon a combination of the above compounds with the organic compounds of the present invention.
The hole-injecting material is selected from compounds which are capable of transporting holes, are capable of receiving holes from the anode, have an excellent effect of injecting holes to a light-emitting layer or a light-emitting material, prevent the movement of excitons generated in a light-emitting layer to an electron-injecting zone or an electron-injecting material and have the excellent capability of forming a thin film. Suitable hole-injecting materials include for example a phthalocyanine derivative, a naphthalocyanine derivative, a porphyrin derivative, oxazole, oxadiazole, triazole, imidazole, imidazolone, imidazolthione, pyrazoline, pyrazolone, tetrahydroimidazole, oxazole, oxadiazole, hydrazone, acylhydrazone, polyarylalkane, stilbene, butadiene, benzidine type triphenylamine, styrylamine type triphenylamine, diamine type triphenylamine, derivatives of these, and polymer materials such as polyvinylcarbazole, polysilane and an electroconducting polymer.
In the organic EL device of the present invention, the hole-injecting material which is more effective is an aromatic tertiary amine derivative or a phthalocyanine derivative. Although not specially limited, specific examples of the tertiary amine derivative include triphenylamine, tritolylamine, tolyldiphenylamine, N,N′-diphenyl-N,N′-(3-methylphenyl)-1,1-biphenyl-4,4′-diamine, N,N,N′,N′-tetra(4-methylphenyl)-1,1′-phenyl-4,4′-diamine, N,N,N′,N′-tetra(4-methylphenyl)-1,1′-biphenyl-4,4′-diamine, N,N′-diphenyl-N,N′-di(1-naphthyl)-1,1′-biphenyl-4,4′-diamine, N,N′-di(methylphenyl)-N,N′-di(4-n-butylphenyl)-phenanthrene-9,10-diamine, 4,4′,4′′-tris(3-methylphenyl)-N-phenylamino)triphenylamine, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, and oligomers or polymers having aromatic tertiary amine structures of these.
Although not specially limited, specific examples of the phthalocyanine (Pc) derivative include phthalocyanine derivatives or naphthalocyanine derivatives such as H2Pc, CuPc, CoPc, NiPc, ZnPc, PdPc, FePc, MnPc, ClAlPc, ClGaPc, ClInPc, ClSnPc, Cl2SiPc, (HO)AlPc, (HO)GaPc, VOPc, TiOPc, MoOPc, and GaPc-O—GaPc.
The hole transporting layer can reduce the driving voltage of the device and improve the confinement of the injected charge recombination within the light emitting layer, comprising the compounds of the present invention. Any conventional suitable aromatic amine hole transporting material described for the hole-injecting layer may be selected for forming this layer.
A preferred class of hole transporting materials is comprised of 4,4′-bis(9-carbazolyl)-1,1′-biphenyl compounds of the formula




wherein R61 and R62 is a hydrogen atom or an C1-C3alkyl group; R63 through R66 are substituents independently selected from the group consisting of hydrogen, a C1-C6alkyl group, a C1-C6alkoxy group, a halogen atom, a dialkylamino group, a C6-C30aryl group, and the like. Illustrative examples of 4,4′-bis(9-carbazolyl)-1,1′-biphenyl compounds include 4,4′-bis(9-carbazolyl)-1,1′-biphenyl and 4,4′-bis(3-methyl-9-carbazolyl)-1,1′-biphenyl, and the like; or 4,4′,4′′-tri-(N-carbazoyl)triphenylamine (TCTA).

In addition, polymeric material can be used as a hole injection material and a hole transporting material, such as poly(N-vinylcarbazole) (PVK), polythiophenes, polypyrrole, polyaniline, and copolymers such as poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate), also called PEDOT/PSS.
The electron transporting layer is not necessarily required for the present device, but is optionally and preferably used for the primary purpose of improving the electron injection characteristics of the EL devices and the emission uniformity. Illustrative examples of electron transporting compounds, which can be utilized in this layer, include the metal chelates of 8-hydroxyquinoline as disclosed in U.S. Pat. Nos. 4,539,507, 5,151,629, and 5,150,006, the disclosures of which are totally incorporated herein by reference.
Examples of suitable electron transporting materials are metal complex compounds and nitrogen-containing five-membered ring derivatives.
Although not specially limited, specific examples of the metal complex compound include lithium 8-hydroxyquinolinate, zinc bis(8-hydroxyquinolinate), copper bis(8-hydroxyquinolinate), manganese bis(8-hydroxyquinolinate), aluminum tris(8-hydroxyquinolinate), aluminum tris(2-methyl-8-hydroxyquinolinate), gallium tris(8-hydroxyquinolinate), beryllium bis(10-hydroxybenzo[h]quinolinate), zinc bis(10-hydroxybenzo[h]quinolinate), chlorogallium bis(2-methyl-8-quinolinate), gallium bis(2-methyl-8-quinolinate)(o-cresolate), aluminum bis(2-methyl-8-quinolinate)(1-naphtholate), gallium bis(2-methyl-8-quinolinate)(2-naphtholate), gallium bis(2-methyl-8-quinolinate)phenolate, zinc bis(o-(2-benzooxazolyl)phenolate), zinc bis(o-(2-benzothiazolyl)phenolate) and zinc bis(o-(2-benzotrizolyl)phenolate). The nitrogen-containing five-membered derivative is preferably an oxazole, thiazole, thiadiazole, or triazole derivative. Although not specially limited, specific examples of the above nitrogen-containing five-membered derivative include 2,5-bis(1-phenyl)-1,3,4-oxazole, 1,4-bis(2-(4-methyl-5-phenyloxazolyl)benzene, 2,5-bis(1-phenyl)-1,3,4-thiazole, 2,5-bis(1-phenyl)-1,3,4-oxadiazole, 2-(4′-tert-butylphenyl)-5-(4′′-biphenyl)1,3,4-oxadiazole, 2,5-bis(1-naphthyl)-1,3,4-oxadiazole, 1,4-bis[2-(5-phenyloxadiazolyl)]benzene, 1,4-bis[2-(5-phenyloxadiazolyl)-4-tert-butylbenzene], 2-(4′-tert-butylphenyl)-5-(4′′-biphenyl)-1,3,4-thiadiazole, 2,5-bis(1-naphthyl)-1,3,4-thiadiazole, 1,4-bis[2-(5-phenylthiazolyl)]benzene, 2-(4′-tert-butylphenyl)-5-(4′′-biphenyl)-1,3,4-triazole, 2,5-bis(1-naphthyl)-1,3,4-triazole and 1,4-bis[2-(5-phenyltriazolyl)]benzene. Another class of electron transport materials are oxadiazole metal chelates, such as bis[2-(2-hydroxyphenyl)-5-phenyl-1,3,4-oxadiazolato]zinc; bis[2-(2-hydroxyphenyl)-5-phenyl-1,3,4-oxadiazolato]beryllium; bis[2-(2-hydroxyphenyl)-5-(1-naphthyl)-1,3,4-oxadiazolato]zinc; bis[2-(2-hydroxyphenyl)-5-(1-naphthyl)-1,3,4-oxadiazolato]beryllium; bis[5-biphenyl-2-(2-hydroxyphenyl)-1,3,4-oxadiazolato]zinc; bis[5-biphenyl-2-(2-hydroxyphenyl)-1,3,4-oxadiazolato]beryllium; bis(2-hydroxyphenyl)-5-phenyl-1,3,4-oxadiazolato]lithium; bis[2-(2-hydroxyphenyl)-5-p-tolyl-1,3,4-oxadiazolato]zinc; b is 2-(2-hydroxyphenyl)-5-p-tolyl-1,3,4-oxadiazolato]beryllium; bis[5-(p-tert-butylphenyl)-2-(2-hydroxyphenyl)-1,3,4-oxadiazolato]zinc; bis[5-(p-tert-butylphenyl)-2-(2-hydroxyphenyl)-1,3,4-oxadiazolato]beryllium; bis[2-(2-hydroxyphenyl)-5-(3-fluorophenyl)-1,3,4-oxadiazolato]zinc; bis[2-(2-hydroxyphenyl)-5-(4-fluorophenyl)-1,3,4-oxadiazolato]zinc; bis[2-(2-hydroxyphenyl)-5-(4-fluorophenyl)-1,3,4-oxadiazolato]beryllium; bis[5-(4-chlorophenyl)-2-(2-hydroxyphenyl)-1,3,4-oxadiazolato]zinc; bis[2-(2-hydroxy phenyl)-5-(4-methoxyphenyl)-1,3,4-oxadiazolato]zinc; bis[2-(2-hydroxy-4-methylphenyl)-5-phenyl-1,3,4-oxadiazolato]zinc; bis[2-.alpha.-(2-hydroxynaphthyl)-5-phenyl-1,3,4-oxadiazolato]zinc; bis[2-(2-hydroxyphenyl)-5-p-pyridyl-1,3,4-oxadiazolato]zinc; bis[2-(2-hydroxyphenyl)-5-p-pyridyl-1,3,4-oxadiazolato]beryllium; bis[2-(2-hydroxyphenyl)-5-(2-thiophenyl)-1,3,4-oxadiazolato]zinc; bis[2-(2-hydroxyphenyl)-5-phenyl-1,3,4-thiadiazolato]zinc; bis[2-(2-hydroxyphenyl)-5-phenyl-1,3,4-thiadiazolato]beryllium; bis[2-(2-hydroxyphenyl)-5-(1-naphthyl)-1,3,4-thiadiazolato]zinc; and bis[2-(2-hydroxyphenyl)-5-(1-naphthyl)-1,3,4-thiadiazolato]beryllium, and the like.
Other suitable compounds for the electron transporting material are hetero-cyclic compounds such as benzimidazole derivatives, benzoxazole derivatives, oxadiazole derivatives, thiadiazole derivative, triazole derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, quinoline derivatives, benzoquinoline derivatives, oligo-pyridine derivatives, e.g. bipyridine derivatives and terpyridine derivatives, naphthylidine derivatives, indole derivatives and naphthalimide derivatives; silole derivatives; and phosphineoxide derivatives.
The property of charge injection can be improved by adding an electron-accepting compound to the hole injection layer and/or the hole transporting layer and electron-donating material to the electron transporting layer.
It is possible to add reducing dopant to the electron transporting layer to improve the EL device property. The reducing dopant is a material that can reduce the electron transporting material. Examples of the reducing dopant are alkaline metals, e.g. Na, K, Rb and Cs, and alkaline earth metals, e.g. Ca, Sr, and Ba.
The organic EL device of the present invention may comprise an inorganic compound layer between at least one of the electrodes and the above organic thin layer. Examples of the inorganic compound used for the inorganic compound layer include various types of oxides, nitrides and oxide nitrides such as alkali metal oxides, alkaline earth metal oxides, rare earth oxides, alkali metal halides, alkaline earth metal halides, rare earth halides, SiOx, AlOx, SiNx, SiON, AlON, GeOx, LiOx, LiON, TiOx, TiON, TaOx, TaON, TaNx and C. In particular, as the component contacting the anode, SiOx, AlOx, SiNx, SiON, AlON, GeOx and C are preferred since a suitable interface layer of injection is formed. As the component contacting the cathode LiF, MgF2, CaF2 and NaF are preferred.
In the organic EL device of the present invention, the light-emitting layer may contain, in addition to the light-emitting organic material of the present invention, at least one of other light-emitting material, other dopant, other hole-injecting material and other electron-injecting material. For improving the organic EL device of the present invention in the stability against temperature, humidity and ambient atmosphere, a protective layer may be formed on the surface of the device, or the device as a whole may be sealed with a silicone oil, or the like.
The electrically conductive material used for the anode of the organic EL device is suitably selected from those materials having a work function of greater than 4 eV. The electrically conductive material includes carbon, aluminum, vanadium, iron, cobalt, nickel, tungsten, silver, gold, platinum, palladium, alloys of these, metal oxides such as tin oxide and indium oxide used for ITO substrates or NESA substrates, and organic electroconducting polymers, such as polythiophene and polypyrrole.
The electrically conductive material used for the cathode is suitably selected from those having a work function of smaller than 4 eV. The electrically conductive material includes magnesium, calcium, tin, lead, titanium, yttrium, lithium, ruthenium, manganese, aluminum and alloys of these, while the electrically conductive material shall not be limited to these. Examples of the alloys include magnesium/silver, magnesium/indium and lithium/aluminum, while the alloys shall not be limited to these. Each of the anode and the cathode may have a layer structure formed of two layers or more as required.
For the effective light emission of the organic EL device, at least one of the electrodes is desirably sufficiently transparent in the light emission wavelength region of the device. Further, the substrate is desirably transparent as well. The transparent electrode is produced from the above electrically conductive material by a deposition method or a sputtering method such that a predetermined light transmittance is secured. The electrode on the light emission surface side has for instance a light transmittance of at least 10%. The substrate is not specially limited so long as it has adequate mechanical and thermal strength and has transparency. For example, it is selected from glass substrates and substrates of transparent resins such as a polyethylene substrate, a polyethylene terephthalate substrate, a polyether sulfone substrate and a polypropylene substrate.
In the organic EL device of the present invention, each layer can be formed by any one of dry film forming methods such as a vacuum deposition method, a sputtering method, a plasma method and an ion plating method and wet film forming methods such as a spin coating method, a dipping method and a flow coating method. The thickness of each layer is not specially limited, while each layer is required to have a proper thickness. When the layer thickness is too large, inefficiently, a high voltage is required to achieve predetermined emission of light. When the layer thickness is too small, the layer is liable to have a pinhole, etc., so that sufficient light emission brightness is hard to obtain when an electric field is applied. The thickness of each layer is for example in the range of from about 5 nm to about 10 μm, for instance about 10 nm to about 0.2 μm.
In the wet film forming method, a material for forming an intended layer is dissolved or dispersed in a proper solvent, such as toluene, ethanol, chloroform, tetrahydrofuran and dioxane, and a thin film is formed from the solution or dispersion. The solvent shall not be limited to the above solvents. For improving the film formability and preventing the occurrence of pinholes in any layer, the above solution or dispersion for forming the layer may contain a proper resin and a proper additive. The resin that can be used includes insulating resins such as polystyrene, polycarbonate, polyarylate, polyester, polyamide, polyurethane, polysulfone, polymethyl methacrylate, polymethyl acrylate and cellulose, copolymers of these, photoconductive resins such as poly-N-vinylcarbozole and polysilane, and electroconducting polymers such as polythiophene and polypyrrole. The above additive includes an antioxidant, an ultraviolet absorbent and a plasticizer.
When the light-emitting organic material of the present invention is used in a light-emitting layer of an organic EL device, an organic EL device can be improved in organic EL device characteristics such as light emission efficiency and maximum light emission brightness. Further, the organic EL device of the present invention is remarkably stable against heat and electric current and gives a usable light emission brightness at a low actuation voltage. The problematic deterioration of conventional devices can be remarkably decreased.
The organic EL device of the present invention has significant industrial values since it can be adapted for a flat panel display of an on-wall television set, a flat light-emitting device, a light source for a copying machine or a printer, a light source for a liquid crystal display or counter, a display signboard, lighting application and a signal light.
The material of the present invention can be used in the fields of an organic EL device, an electrophotographic photoreceptor, a photoelectric converter, a solar cell, and an image sensor.
Various features and aspects of the present invention are illustrated further in the examples that follow. While these examples are presented to show one skilled in the art how to operate within the scope of this invention, they are not to serve as a limitation on the scope of the invention where such scope is only defined in the claims. Unless otherwise indicated in the following examples and elsewhere in the specification and claims, all parts and percentages are by weight.


EXAMPLES
Example 1
Synthesis of 2,8-Bis-((E)-styryl)-dibenzofuran




1a) 2,8-Dibromodibenzofuran

Bromine (92.6 g, 0.58 mol) in acetic acid (54 g) is added at 75° C. to a solution of dibenzofuran (23.2 g, 0.14 mol) in acetic acid (232 g). The mixture is then stirred at 75° C. for 3 hours. The reaction mixture is cooled to room temperature and poured into H2O. The orange solid is washed with Na2S2O3 aq. and H2O. The crude product is then purified by recrystallization from n-hexane, wherein the pure product is obtained as a white solid (38% yield; mp.: 226° C.).
1H-NMR (CDCl3, ppm): 7.65 (d, 2H), 7.59 (dd, 2H), 8.03 (d, 2H).
1b) 2,8-Bis-((E)-styryl)-dibenzofuran
Tetrethylamine hydroxide (13.6 g, 18.4 mmol), tetrakis(triphenylphosphine)palladium(0) (142 mg) and trans-2-phenylvinylboronic acid (2.3 g, 15.3 mmol) are added to a solution of the product from example 1a) (2.00 g, 6.14 mmol) in N,N′-Dimethylacetamide (DMA) (30 ml). The mixture is then stirred at 110° C. for 24 hours. The reaction mixture is cooled to room temperature and poured into H2O. A gray crude product is obtained after filtration and washing with n-hexane. The crude product is purified by silicagel column chromatography with CH2Cl2, which result in a white solid (71% yield, mp.: 226° C.).
1H-NMR (CDCl3, ppm): 7.26-7.30 (m, 6H), 7.39 (t, 4H), 7.54-7.58 (m, 6H), 7.65 (dd, 2H), 8.12 (d, 2H)
Example 2
Synthesis of 1,5-dibenzofuranyl-3,7-di-tert-butylnaphthalene




2a) 1,5-dibromo-3,7-di-tert-butylnaphthalene

Fe (212 mg) and bromine (18.3 g, 0.11 mol) in carbontetrachloride (75 ml) are added at 0° C. to a solution of 2,6-di-tert-butylnaphthalene (25 g, 0.1 mol) in carbontetrachloride (300 ml). The mixture is then stirred at 0° C. for 3.5 hours. The reaction mixture is poured into H2O and then the organic layer is washed with Na2S2O3 aq. and H2O. The organic layer is dried over MgSO4 and concentrated by evaporation. The crude product is then purified by silicagel column chromatography with n-hexane, which result in a white solid (31% yield; mp.: 226° C.).
1H-NMR (CDCl3, ppm): 1.41 (s, 18H), 7.88 (d, 2H), 8.11 (d, 2H).
2b) 1,5-Dibenzofuranyl-3,7-di-tert-butylnaphthalene
Tetrethylaminehydroxide (3.5 g, 14.2 mmol), tetrakis(triphenylphosphine)palladium(0) (100 mg) and 4-denzofuranboronic acid (3 g, 14.0 mmol) are added to a solution of the product from example 2a) (1.88 g, 4.72 mmol) in DMA (30 ml). The mixture is stirred at 110° C. for 1 hour, then cooled to room temperature, whereby a yellow solid product is obtained which is isolated by filtration and washed with H2O. The yellow solid is then dissolved in CH2Cl2 and dried over MgSO4. Concentration by evaporation and silicagel column chromatography with ethylacetate/hexane=1/30 as eluent afforded a pure yellow solid product (65% yield; mp.: 226° C.).
1H-NMR (CDCl3, ppm): 1.98 (s, 18H), 7.38-7.58 (m, 8H), 7.67 (d, 2H), 7.77 (d, 2H), 7.82 (d, 2H), 8.08 (dd, 2H), 8.11 (dd, 2H).
The compounds shown below (examples 3-10) are prepared in analogues manner using the appropriate educts.












Example
Structure
Mp. [° C.]







3




247


 


4




290


 


5




255


 


6







 


7




230


 


8







 


9







 


10 













Example 11
Synthesis of 2-Phenanthren-9-yl-8-pyren-1-yl-dibenzofuran
11a) 2-Bromodibenzofuran
Bromine (23.8 g, 0.156 mol) in acetic acid (5 g) is added at 50° C. to a solution of dibenzofuran (25 g, 0.149 mol) in acetic acid (230 g). The mixture is then stirred at 50° C. for 4 hours. The reaction mixture is cooled to room temperature and poured into H2O. The orange solid is washed with Na2S2O3 aq. and H2O. The crude product is then purified by recrystallization from toluene/CH2Cl2, wherein the pure product is obtained as a white solid (13% yield).
1H-NMR (CDCl3, ppm): 7.59-7.73 (m, 5H), 7.90 (d, 1H), 8.70 (d, 1H)
11b) 2-Bromo-8-iododibenzofuran
2-Bromodibenzofuran (2.5 g, 10.1 mmol), orthoperiodic acid (0.49 g, 2.15 mmol), iodine (1.02 g, 4.02 mmol), sulfuric acid, H2O (2 ml) and acetic acid (10 ml) are put into a reaction vessel and the mixture is stirred at 70° C. for 3 hours. After cooling to room temperature the reaction mixture is poured into water and filtered. The white solid is washed by methanol and the desired product is obtained (1.92 g, 51%).
1H-NMR (CDCl3, ppm): 7.34 (d, 1H), 7.44 (d, 1H), 7.57 (dd, 1H), 7.75 (dd, 1H), 8.01 (d, 1H), 8.22 (d, 1H)
11c) 2-Bromo-8-pyren-1-yl-dibenzofuran




20% aq. solution of tetraethylammoninm hydroxide (5.33 g, 7.24 mmol), tetrakis-(triphenylphosphine)palladium(0) (200 mg) and 1-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl) pyrene (1.74 g, 5.3 mmol) are added to a solution of the product of example 11b) (1.81 g, 4.83 mmol) in N,N′-dimethylacetamide (DMA) (70 ml). The mixture is then stirred at 120° C. for 3 hours. The reaction mixture is cooled down to room temperature and poured into H2O. A gray crude product is obtained after filtration and washing with n-hexane. The crude product is purified by silicagel column chromatography with hexane/CH2Cl2—, which result in a white solid (71% yield).
1H-NMR (CDCl3, ppm): 7.53 (d, 1H), 7.61 (dd, 1H), 7.75 (d, 2H), 8.01-8.28 (m, 12H)




11d) 2-Phenanthren-9-yl-8-pyren-1-yl-dibenzofuran (A-17) is prepared in analogy to example 2b) using the compound obtained in step 11c) and 9-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl) phenanthrene.

1H-NMR (CDCl3, ppm): 7.53-7.57 (m, 1H), 7.60-7.70 (m, 4H), 7.74-7.83 (m, 4H), 7.90-8.00 (m, 2H), 8.01-8.09 (m, 3H), 8.15 (d, 2H), 8.15-8.26 (m, 6H), 8.74 (d, 1H), 8.80 (d, 1H)
The compounds of examples 12 and 13, which are shown below, are prepared in analogues manner to example 11 using the appropriate educts.
Example 12
Diphenyl-[4-(8-pyren-1-yl-di benzofuran-2-yl)-phenyl]-amine




1H-NMR (CDCl3, ppm): 7.00-7.06 (m, 2H), 7.12-7.18 (m, 6H), 7.24-7.28 (m, 3H), 7.54-7.58 (d, 2H), 7.64-7.78 (m, 4H), 8.01-8.28 (m, 12H)
Example 13
2-Naphthalen-2-yl-8-pyren-1-yl-dibenzofuran




1H-NMR (CDCl3, ppm): 7.46-7.53 (m, 2H), 7.73-7.96 (m, 8H), 8.01-8.15 (m, 6H), 8.17-8.29 (m, 5H), 8.32 (d, 1H)
Example 14
9,10-Bis-di benzofuran-4-yl-2,6-di-tert-butyl-anthracen




Compound B-14 is prepared in analogues manner to example 2 using the appropriate educts.
1H-NMR (CDCl3, ppm): 1.15 (s, 18H), 7.35-7.43 (m, 8H), 7.58-7.67 (m, 8H), 8.08-8.12 (m, 2H), 8.18 (dd, 2H)
Example 15
Synthesis of 4-(2,6-Di-tert-butyl-10-naphthalen-2-yl-anthracen-9-yl)-dibenzofuran
15a) 9-Bromo-2,6-di-tert-butyl-anthracene
Bromine (3.02 g, 18.9 mmol) is added at 0° C. to a solution of 2,6-di-tert-butylanthracene (5.0 g, 17.2 mol) in carbontetrachloride (200 ml). The mixture is then stirred at 0° C. for 15 hours. After allowing to heat up to room temperature, half the amount of solvent is evaporated and the resulting mixture is poured into methanol. The precipitate is collected by filtration, recrystallized from n-hexane/methanol and the desired product is obtained as a white solid (1.13 g).
1H-NMR (CDCl3, ppm): 1.47 (s, 9H), 1.48 (s, 9H), 7.58 (dd, 1H), 7.67 (dd, 1H), 7.85 (d, 1H), 7.91 (d, 1H), 8.33 (s, 1H), 8.38 (d, 1H), 8.43 (d, 1H)
15b) 9-Bromo-2,6-di-tert-butyl-10-iodo-anthracene
Iodination is done in the same manner as described in example 11b) using the compound obtained in example 15a) as starting material.
1H-NMR (CDCl3, ppm): 1.48 (2s, 18H), 7.65-7.72 (m, 2H), 8.42-8.52 (m, 4H)
15c) 4-(10-Bromo-2,6-di-tert-butyl-anthracen-9-yl)-dibenzofuran




The compound shown above is prepared in the same manner as described in example 11c) using the compound obtained in example 15b) and 1-dibenzofuranylboronic acid as starting materials.
1H-NMR (CDCl3, ppm): 1.18 (s, 9H), 1.46 (s, 9H), 7.29-7.33 (m, 1H), 7.35-7.42 (m, 3H), 7.48-7.59 (m, 4H), 7.68 (dd, 1H), 8.07 (m, 1H), 8.15 (dd, 1H), 8.53 (d, 1H), 8.58 (d, 1H)




15d) 4-(2,6-Di-tert-butyl-10-naphthalen-2-yl-anthracen-9-yl)-dibenzofuran (A-35) is prepared in the same manner as described in example 2b) using the compound obtained in step 15c) and 2-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl) naphthalene as starting materials.
1H-NMR (CDCl3, ppm): 1.16 (s, 9H), 1.21 (s, 9H), 7.35-7.42 (m, 5H), 7.55-7.73 (m, 9H), 7.92-7.97 (m, 1H), 8.01-8.11 (m, 4H), 8.16-8.19 (m, 1H)
Example 16
4-(2,6-Di-tert-butyl-10-pyren-1-yl-anthracen-9-yl)-dibenzofuran




Example 15 is repeated except using 1-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl) pyrene in the last step.
1H-NMR (CDCl3, ppm): 1.05 (s, 9H), 1.14 (s, 9H), 7.24-8.44 (m, 22H)
Example 17
2,6-Di-pyren-1-yl-dibenzofuran
17a) 6-Bromo-2-iodo-dibenzofuran




6-Bromo-2-iodo-dibenzofuran is prepared in the same manner as described in example 11b), except using 4-bromodibenzofurane as a starting material.
1H-NMR (CDCl3, ppm): 7.22-7.27 (t, 1H), 7.42-7.45 (d, 1H), 7.62-7.66 (dd, 1H), 7.75-7.79 (dd, 1H), 7.82-7.85 (dd, 1H), 8.26 (d, 1H)
17b) 6-Bromo-2-pyren-1-yl-dibenzofuran




6-Bromo-2-pyren-1-yl-dibenzofuran is prepared in the same manner as described in example 11c), except using 6-Bromo-2-iodo-dibenzofuran as a starting material.
1H-NMR (CDCl3, ppm): 7.24-7.28 (t, 1H), 7.65-7.68 (dd, 1H), 7.74-7.77 (dd, 1H), 7.82-7.85 (d, 1H), 7.91-7.94 (dd, 1H), 8.01-8.06 (m, 3H), 8.12-8.27 (m, 7H)
17c) 2,6-Di-pyren-1-yl-dibenzofuran (A-58)




A-58 is prepared in analogy to A-17 using the appropriate educts.
1H-NMR (CDCl3, ppm): 7.58-7.62 (m, 2H), 7.67-7.74 (m, 2H), 8.02-8.10 (m, 6H), 8.13-8.30 (m, 13H), 8.35-8.38 (d, 1H)
Example 18
6-Phenanthren-9-yl-2-pyren-1-yl-dibenzofuran




A-59 is prepared in analogy to A-58 using the appropriate educts.
1H-NMR (CDCl3, ppm): 7.52-7.61 (m, 3H), 7.63-7.80 (m, 6H), 7.95-8.28 (m, 13H), 8.80-8.83 (d, 1H), 8.84-8.88 (d, 1H)
Example 19




A-60 is prepared in analogy to A-17 using the appropriate educts.
1H-NMR (CDCl3, ppm): 6.64-6.89 (m, 5H), 7.04-7.46 (m, 11H), 8.0-8.26 (m, 14H)
Example 20




A-61 is prepared in analogy to A-58 using the appropriate educts.
1H-NMR (CDCl3, ppm): 6.62-6.86 (m, 5H), 7.02-7.14 (m, 5H), 7.30-7.40 (m, 5H), 7.58 (s, 1H), 7.66-8.26 (m, 14H)
Application Examples
Application Example 1
Compounds A-1, B-1, C-1, C-2, A-9, A-10 and A-7, respectively are deposited under vacuum on a glass plate in a thickness of 60 nm. Fluorescence spectra of the deposited films are measured by fluorescence spectrophotometer (F-4500, HITACHI). The emission λmax is shown below.














Compound
Emission λmax [nm]









A-1
421



B-1
383



C-1
420



C-2
387



A-9
364



A-10
474



A-7
454










Application Example 2
The following device structure is prepared: ITO/CuPC/TCTA/Compound B-1/TPBI/LiF/Al where ITO is indium tin oxide, CuPC is copper phthalocyanine, TCTA is 4,4′,4′′-tri-(N-carbazoyl)triphenylamine and TPBI is 1,3,5-tris-(N-phenyl-benzimidazol-2-yl)benzene. Using this device structure, a brightness of 50 cd/m2 is observed at 100 mA/cm2.
Application Example 3
The following device structure is prepared: ITO/CuPC/TCTA/Compound B-1+Compound G-1 (1.1% by weight)/TP131/LiF/Al. Using this device structure, a brightness of 500 cd/m2 is observed at 100 mA/cm2.




Application Example 4
The following device structure is prepared: ITO/CuPC/TCTA/Compound C-2/TPBI/LiF/Al. Using this device structure, a brightness of 120 cd/m2 is observed at 100 mA/cm2.
Application Example 5
The following device structure is prepared: ITO/CuPC/TCTA/Compound C-2+Compound G-1 (1.9% by weight)/TP131/LiF/Al. Using this device structure, a brightness of 70 cd/m2 is observed at 100 mA/cm2.
Application Example 6
The following device structure is prepared: ITO/CuPC/NPD/Compound B-1/TPBI/LiF/Al where NPD is N,N′-Di(naphthalene-1-yl)-N,N′-diphenyl-benzidine. Using this device structure, a brightness of 370 cd/m2 is observed at 100 mA/cm2.
Application Example 7
The following device structure is prepared: ITO/CuPC/NPD/Compound B-1+TBPe (1.4%)/TPBI/LiF/Al where TPBe is 2,5,8,11-tetra-t-butylperylene. Using this device structure, a brightness of 680 cd/m2 is observed at 88 mA/cm2.
Application Example 8
The following device structure is prepared: ITO/CuPC/NPD/Compound A-10/TPBI/LiF/Al. Using this device structure, a brightness of 3,800 cd/m2 is observed at 111 mA/cm2.
Application Example 9
The following device structure is prepared: ITO/CuPC/NPD/Compound A-10+TBPe (1.5%)/TPBI/LiF/Al. Using this device structure, a brightness of 2,030 cd/m2 is observed at 90 mA/cm2.
Application Examples 10 to 21
The following device structure is prepared: ITO/CuPC/NPD/Emitting layer (dibenzofuran of the present invention as a host+TBPe as a guest)/TPBI/LiF/Al. Using this device structure, bright blue EL emission is observed. The EL properties of the devices are summarized in Table 1.







TABLE 1







EL properties obtained in application exampleS 10 TO 21















Guest 








(TBPe)






Appli-

Concen- 

Current

Emission 


cation

tration
Brightness
Efficiency
Voltage
peak


Example
Host
(%)
(cd/m2)
(cd/A)
(V)
(nm)
















10
C-2
2.4
158
2.5
10
467, 493


11
C-1
1.7
99
1.1
7
462, 489


12
A-17
—
133
3.3
7.4
465


13
A-17
1.6
79
4.0
7.2
467, 492


14
B-14
—
86
2.2
7.6
459


15
B-14
1.8
97
4.9
7.1
462, 490


16
A-57
—
108
2.7
8.3
460


17
A-57
1.6
95
2.4
8.1
464, 489


18
A-43
—
120
3.0
5.1
461


19
A-43
1.5
96
4.8
4.7
465, 491


20
A-50
—
139
3.5
6.8
466


21
A-50
1.5
88
4.4
6.4
467, 492


22 
A-35
—
86
4.3 
7.6
467


23
A-35
1.3
98
4.9
7.4
461, 488


24 
A-58
—
104
5.2 
6.4 
465


25 
A-58
2.1
89
4.4 
6.7
467, 490









Application Example 26
The following device structure is prepared: ITO/CuPC/NPD/Emitting layer (dibenzofuran of the present invention as a host+dibenzofuran of the present invention as a guest)/TPBI/LiF/Al. Using this device structure, bright blue EL emission is observed. The EL properties of the device is summarized in Table 2.







TABLE 2







EL properties obtained in application example 26

















Current

Emission


Application


Brightness
Efficiency 
Voltage
Peak


Example
Host
Guest
(cd/m2)
(cd/A)
(V)
(nm)
















26
A-17
B-14
83
2.1
7.5
462




(5.1%)

## Claims

1. An electroluminescent device, comprising in the light emitting layer a compound of the formula




and a phosphorescent metal complex of Ir, Pt, Eu, Ru, Rh, Pd, Ag, Re, Os and Au as dopant, wherein R81 and R88 are independently of each other H, —OR201, —SR202 and/or —NR203R204, C1-C24alkyl; C1-C24alkyl, which is substituted by E and/or interrupted by D; C2-C18alkenyl, C2-C18alkenyl, which is substituted by E, C3-C8cycloalkyl, C3-C8cycloalkyl, which is substituted by G, aryl, aryl, which is substituted by G, heteroaryl, or heteroaryl, which is substituted by G, silyl, SiR62R63R64, —CN, cyclic ether, —B(OR65)2 and/or halogen, wherein
R201 is hydrogen, C1-C24alkyl, C1-C24alkyl, which is substituted by E and/or interrupted by D; C2-C12alkenyl, C3-C6alkenoyl, C3-C8cycloalkyl, or benzoyl, each of which may optionally be substituted by one or more groups C1-C6alkyl, halogen, —OH and/or C1-C4alkoxy; phenyl, naphthyl, phenanthryl, anthranyl, or pyrenyl, each of which may optionally be substituted by halogen, —OH, C1-C12alkyl, C1-C12alkoxy, phenoxy, C1-C12alkylsulfanyl, phenylsulfanyl, —N(C1-C12alkyl)2 and/or diphenylamino;
R202 is C1-C24alkyl, C1-C24alkyl, which is substituted by E and/or interrupted by D; C2-C12alkenyl, C1-C8alkanoyl, C2-C12alkenyl, C3-C6alkenoyl; C3-C8cycloalkyl, or benzoyl, each of which may optionally be substituted by one or more groups C1-C6alkyl, halogen, —OH, C1-C4alkoxy or C1-C4alkylsulfanyl; phenyl, naphthyl, phenanthryl, anthranyl, or pyrenyl, each of which may optionally be substituted by halogen, C1-C12alkyl, C1-C12alkoxy, phenyl-C1-C3alkyloxy, phenoxy, C1-C12alkylsulfanyl, phenylsulfanyl, —N(C1-C12alkyl)2, diphenylamino, —(CO)O(C1-C8alkyl), —(CO)—C1-C8alkyl, or (CO)N(C1-C8alkyl)2;
R203 and R204 are independently of each other hydrogen, C1-C24alkyl, C1-C24alkyl, which is substituted by E and/or interrupted by D; C2-C2alkenyl, C3-C8cycloalkyl, or benzoyl, each of which may optionally be substituted by one or more groups C1-C6alkyl, halogen, —OH, or C1-C4alkoxy; phenyl-C1-C3alkyl, C1-C8alkanoyl, C3-C12alkenoyl; phenyl naphthyl, phenanthryl, anthranyl, or pyrenyl, each of which is optionally substituted by C1-C12alkyl, benzoyl or C1-C12alkoxy; or R203 and R204 together are C2-C8alkylene, or branched C2-C8alkylene optionally interrupted by —O—, —S—, or —NR205— and/or optionally substituted by hydroxyl, C1-C4alkoxy, C2-C4alkanoyloxy, or benzoyloxy, wherein the ring formed by R203 and R204 can optionally be condensed one or two times by phenyl which can be substituted one to three times with C1-C8-alkyl, C1-C8-alkoxy, halogen, or cyano;
R205 is hydrogen, C1-C24alkyl, C1-C24alkyl, which is substituted by E and/or interrupted by D; C2-C5alkenyl, C3-C8cycloalkyl, phenyl-C1-C3alkyl, C1-C8alkanoyl, C3-C12alkenoyl; benzoyl; phenyl, naphthyl, phenanthryl, anthranyl, or pyrenyl, each of which is optionally substituted by C1-C12alkyl, benzoyl, or C1-C12alkoxy;
D is —CO—, —COO—, —OCOO—, —S—, —SO—, —SO2—, —O—, —NR5—, —SiR61R62—, —POR5—, —CR63═CR64—, or —C≡—;
E is halogen, C6-C14aryl, which may be substituted by —OR5, —SR5, —NR5R6, SiR62′R63′R64′, wherein R62′, R63′ and R64′ are independently of each other a C1-C8alkyl group, a C6-C24aryl group or a C7-C12aralkyl group, —CN, cyclic ether and/or —B(OR65)2, wherein R65 is hydrogen, C1-C24alkyl, C3-C8cycloalkyl, C7-C24aralkyl, C2-C18alkenyl, C2-C24alkynyl, hydroxy, mercapto, C1-C24alkoxy, C1-C24alkylthio, C6-C30aryl, C2-C30heteroaryl, halogen, haloalkane, silyl, siloxanyl, and an alicyclic ring formed with adjacent substituents R65; —OR5, —SR5, —NR5R6, —COR8, —COOR7, —CONR5R6, —CN, halogen, silyl, C1-C18alkyl, or heteroaryl,
G is E, or C1-C18alkyl, wherein R5 and R6 are independently of each other H, C6-C18aryl; C6-C18aryl which is substituted by C1-C18alkyl, C1-C18alkoxy, or silyl; C1-C18alkyl or C1-C18alkyl which is interrupted by —O—; or
R5 and R6 together form a five or six membered ring,
R7 is H, C6-C18aryl, C7-C12alkylaryl, which are optionally substituted by C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl; or C1-C18alkyl which is interrupted by —O—;
R8 is C6-C18aryl; C6-C18aryl which is substituted by C1-C18alkyl, or C1-C18alkoxy; C1-C18alkyl, C7-C12alkylaryl, or C1-C18alkyl which is interrupted by —O—;
R61 and R62 are independently of each other C6-C18aryl; C6-18aryl which is substituted by C1-C18alkyl, C1-C18alkoxy; or C1-C18alkyl which is interrupted by —O—,
R63 and R64 are independently of each other H, C6-C18aryl; C6-18aryl which is substituted by C1-C18alkyl, C1-C18alkoxy; or C1-C18alkyl which is interrupted by —O—,
wherein
R82, R83, R86 and R87 are independently of each other a group of the formula —(W1)a—(W2)b—W3,
a and b are 0, or 1,
W1 and W2 are independently of each other a group of formula





and
R11, R11′, R12, R12′, R13, R13′, R15, R15′, R16, R16′, R17 and R17′ are independently of each other H, E, tri(C1-C8alkyl)silyl, C6-C18aryl; C6-C18aryl which is substituted by G; C1-C18alkyl; C1-C18alkyl which is substituted by E and/or interrupted by D; C1-C18alkoxy; or C1-C18alkoxy which is substituted by E and/or interrupted by D; C7-C18aralkyl; or C7-C18aralkyl which is substituted by G;
R18 and R19 are independently of each other C1-C18alkyl; C1-C18alkoxy, C6-C18aryl; C7-C18aralkyl; or R18 and R19 together form a ring, which can optionally be substituted by C1-C8alkyl,
W3 is a group of formula —NR70R71, wherein R70 and R71 are independently of each other a group of formula





wherein R72, R73 and R74 are independently of each other hydrogen, C1-C8alkyl, a hydroxyl group, a mercapto group, C1-C8alkoxy, C1-C8alkylthio, halogen, halo-C1-C8alkyl, a cyano group, an aldehyde group, a ketone group, a carboxyl group, an ester group, a carbamoyl group, an amino group, a nitro group, a silyl group or a siloxanyl group, or R70 and R71 together with the nitrogen atom to which they are bonded form a five or six membered heterocyclic ring, which can be condensed by one or two optionally substituted phenyl groups; with the proviso that b is 1, if R70 and R71 are independently of each other a group of formula

2. The electroluminescent device according to claim 1, wherein the light emitting layer comprises a compound of formula




wherein R81, R83, R86 and R88 are as defined in claim 1.

3. The electroluminescent device according to claim 1, wherein the light emitting layer comprises a compound of formula




wherein
R81 and R83 are independently of each other H, or NR203R204,
R203 and R204 together form a five membered ring, wherein the ring formed by R203 and R204 can optionally be condensed one or two times by phenyl;
R86 and R88 are independently of each other a group of the formula —(W1)a—(W2)b—W3,
a and b are 0, or 1,
W1 and W2 are independently of each other a group of formula




R11, R11′, R12 and R12′ R are H; and
W3 is a group of formula —NR70R71, wherein R70 and R71 together with the nitrogen atom to which they are bonded form a five or six membered heterocyclic ring, which can be condensed by one or two optionally substituted phenyl groups.

4. The electroluminescent device according to claim 1, wherein the compound of formula (Ia) is a compound of formula

5. A method of forming a light emitting layer of an electroluminescent device by incorporating the compounds of formula (Ia), (Ib), or (Ic) according to claim 1 with phosphorescent metal complexes of Ir, Pt, Eu, Ru, Rh, Pd, Ag, Re, Os and Au as a dopant therein.