Materials for organic electroluminescent devices
The present invention describes dibenzofuran derivatives substituted by electron-deficient heteroaryl groups, and electronic devices, especially organic electroluminescent devices, comprising these compounds as triplet matrix materials.
1 . A compound of formula (1)
where the symbols used are as follows:
Y is O or S;
Z is the same or different at each instance and is CR or N, with the proviso that at least two Z are N;
Ar 1 is the same or different at each instance and is an aromatic ring system which has 6 to 40 aromatic ring atoms and may be substituted by one or more R radicals, or a heteroaromatic ring system containing at least one nitrogen atom which has 5 to 40 aromatic ring atoms and which is bonded to the dibenzofuran or dibenzothiophene via the at least one nitrogen atom and which may be substituted by one or more R radicals, or a dibenzofuran or dibenzothiophene group which may be substituted by one or more R radicals;
Ar 2 is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted by one or more R radicals;
R is the same or different at each instance and is H, D, F, Cl, Br, I, N(Ar′) 2 , N(R 1 ) 2 , OAr′, SAr′, CN, NO 2 , OR 1 , SR 1 , COOR 1 , C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R 1 radicals, where one or more nonadjacent CH 2 groups may be replaced by Si(R 1 ) 2 , C↑O, NR 1 , O, S or CONR 1 , or an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms, preferably 5 to 40 aromatic ring atoms, and may be substituted in each case by one or more R 1 radicals; at the same time, two R radicals together may also form a ring system;
Ar′ is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted by one or more R 1 radicals; at the same time, two Ar′ radicals bonded to the same nitrogen atom may also be bridged to one another by a single bond or a bridge selected from N(R 1 ), C(R 1 ) 2 , O and S;
R is the same or different at each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , OR 2 , SR 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may each be substituted by one or more R 2 radicals, where one or more nonadjacent CH 2 groups may be replaced by Si(R 2 ) 2 , C═O, NR 2 , O, S or CONR 2 and where one or more hydrogen atoms in the alkyl, alkenyl or alkynyl group may be replaced by D, F, Cl, Br, I or CN, or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted in each case by one or more R 2 radicals; at the same time, two or more R 1 radicals together may form an aliphatic ring system;
R 2 is the same or different at each instance and is H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical, especially a hydrocarbyl radical, having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F;
p, q are the same or different at each instance and are 0, 1, 2 or 3;
r is 0, 1, 2, 3 or 4, with the proviso that r is not more than (4-j);
S is 0, 1, 2 or 3, with the proviso that s is not more than (3-k);
j, k are the same or different at each instance and are 0, 1, 2 or 3, with the proviso that j+k≥1.
2 . The compound according to claim 1 , wherein all three Z groups are N, or in that two Z groups are N and the third Z group is CH.
3 . The compound according to claim 1 , wherein the compound is selected from the compounds of the formula (4)
where the symbols and indices used have the definitions given in claim 1 .
4 . The compound according to claim 1 , wherein the compound is compounds of the formula (5)
where the symbols and indices used have the definitions given in claim 1 .
5 . The compound according to claim 1 , wherein the compound is selected from the compounds of the formulae (6a) and (6b)
where the symbols and indices used have the definitions given above.
6 . The compound according to claim 1 , wherein the compound is selected from the compounds of the formulae (7a) and (7b)
where the symbols used have the definitions given in claim 1 .
7 . The compound according to claim 1 , wherein, when j=1, the Ar 1 group is bonded in the 7 or 8 position of the dibenzofuran or dibenzothiophene, and in that, when k=1, the Ar 1 group is bonded in the 3 or 4 position of the dibenzofuran or dibenzothiophene.
8 . The compound according to claim 1 , wherein Ar 2 is the same or different at each instance and represents an aromatic or heteroaromatic ring system which has 6 to 30 aromatic ring atoms and may be substituted by one or more nonaromatic R radicals.
9 . The compound according to claim 1 , wherein Ar 1 is an aromatic ring system which has 6 to 30 aromatic ring atoms and may be substituted by one or more nonaromatic R radicals, or N-carbazolyl which may be substituted by one or more R radicals, or dibenzofuran or dibenzothiophene, each of which may be substituted by one or more R radicals.
10 . A formulation comprising at least one compound according to claim 1 and at least one further compound and/or solvent.
11 . An electronic device comprising at least one compound according to claim 1 .
12 . An organic electroluminescent device (OLED) comprising the compound according to claim 1 is used as matrix material for a phosphorescent emitter in an emitting layer.
13 . An organic electroluminescent device (OLED) comprising the compound according to claim 1 is used in combination with a further matrix material for a phosphorescent emitter in an emitting layer, where the further matrix material is a compound of formula (9)
where R 1 , R 2 and Ar′ have the definitions detailed in claim 1 and the further symbols and indices used are as follows:
R A is H, -L 3 -Ar 5 or -L 1 -N(Ar′) 2 ;
R B is Ar 4 or -L 2 -N(Ar′) 2 ;
L 1 , L 2 are the same or different at each instance and are a single bond or an aromatic or heteroaromatic ring system which has 5 to 30 aromatic ring atoms and may be substituted by one or more R 1 radicals;
L 3 is a single bond or an aromatic or heteroaromatic ring system which has 5 to 30 aromatic ring atoms and may be substituted by one or more R 2 radicals, where one substituent R 1 may form a ring with a substituent R on the carbazole;
Ar 4 is an aromatic ring system having 6 to 40 aromatic ring atoms or a heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may be substituted by one or more R 1 radicals;
Ar 5 is the same or different at each instance and is an unsubstituted or substituted 9-arylcarbazolyl or unsubstituted or substituted carbazol-9-yl, which may be substituted by one or more R 1 radicals, and where one or more instances each of two R 1 radicals or one R 1 radical together with one R radical may independently form a monocyclic or polycyclic, aliphatic, aromatic or heteroaromatic ring, where aryl is an aromatic or heteroaromatic ring system which has 5 to 30 aromatic ring atoms and may be substituted by R 1 ;
u at each instance is independently 0, 1, 2 or 3;
v at each instance is independently 0, 1, 2, 3 or 4.