Heteroleptic transition metal-carbene complexes and their use in organic light-emitting diodes (OLEDS)
The present invention relates to heteroleptic carbene complexes comprising at least two different carbene ligands, to a process for preparing the heteroleptic carbene complexes, to the use of the heteroleptic carbene complexes in organic light-emitting diodes, to organic light-emitting diodes comprising at least one inventive heteroleptic carbene complex, to a light-emitting layer comprising at least one inventive heteroleptic carbene complex, to organic light-emitting diodes comprising at least one inventive light-emitting layer, and to devices which comprise at least one inventive organic light-emitting diode.
1. A heteroleptic carbene complex of the general formula (Ii) comprising two different carbene ligands (IIa) and (IIb),
wherein the ligand (IIa)
is
and
wherein, in the carbene ligand (IIb)
Do 1 is a donor atom selected from the group consisting of C, P, N and Si;
Do 2 is a donor atom selected from the group consisting of C, N, P, O and S;
r is 2 when Do 1 is C or Si, is 1 when Do 1 is N or P;
s is 2 when Do 2 is C, 1 when Do 2 is N or P, and are each 0 when Do 2 is O or S;
X is a spacer selected from the group consisting of silylene, alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 13 , PR 14 , BR 15 , O, S, SO, SO 2 , CO, CO—O, O—CO and (CR 16 R 17 ) w , where one or more nonadjacent (CR 16 R 17 ) groups may be replaced by NR 13 , PR 14 , BR 15 , O, S, SO, SO 2 , CO, CO—O, or O—CO;
w is from 2 to 10;
R 13 , R 14 , R 15 , R 16 , and R 17 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl;
p is 0 or 1;
q is 0 or 1;
p′ is 0;
q′ is 0;
Y 1 and Y 2 are each independently hydrogen, a carbon group selected from the group consisting of alkyl, aryl, heteroaryl, alkynyl and alkenyl groups, or together form a bridge between the donor atom Do 1 and the nitrogen atom N which has at least two atoms, of which at least one is a carbon atom;
R 1 and R 2 are each independently hydrogen, an alkyl, an aryl, a heteroaryl, an alkynyl, an alkenyl, or R 1 and R 2 together form a bridge having a total of from three to five atoms, of which 1 to 5 atoms may be heteroatoms and the remaining atoms are carbon atoms, so that the group
forms a five- to seven-membered ring which optionally—in addition to the double bond already present—may have one further double bond or—in the case of a six- or seven-membered ring—two further double bonds, and may optionally be substituted by alkyl or aryl groups and/or groups with donor or acceptor action, and may optionally comprise at least one heteroatom, and the five- to seven-membered ring may optionally be fused to one or more further rings;
Y 1 and R 1 or Y 2 and R 1′ may be bonded to one another via a bridge where the bridge is a group selected from the group consisting of alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, O—CO and (CR 21 R 22 ) x , where one or more nonadjacent (CR 21 R 22 ) groups may be replaced by NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, or O—CO, where
x is from 2 to 10, and
R 18 , R 19 , R 20 , R 21 , R 22 , R 30 and R 31 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl;
R 3 is selected from the group consisting of hydrogen, an alkyl, aryl, heteroaryl, alkynyl and alkenyl radical;
Y 3 is a hydrogen, an alkyl, alkynyl, or alkenyl radical; and
in the carbene ligand (IIb) has the structure
wherein one occurrence of Z′ in an o-position relative to the bonding site with Do 1 is CH, the other occurrence of Z′ in an o-position relative to the bonding site with Do 1 is CR 12′ , each occurrence of Z′ in an m- or p-position relative to the bonding site with Do 1 is independently CR 12′ or N, provided 0 or only 1 Z′ is N, and
R 12′ in the Z′ groups are each independently selected from the group consisting of H, an alkyl, aryl, heteroaryl, alkynyl, alkenyl radical and a radical with donor or acceptor action, where 2 R 12′ radicals optionally form a fused ring, wherein the fused ring may optionally comprise at least one heteroatom;
wherein, the aromatic base of the structure
or one of the R 12′ radicals is optionally bonded to Y 2 via a bridge,
wherein the bridge is selected from the group consisting of alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, O—CO and (CR 21 R 22 ) x , where one or more nonadjacent (CR 21 R 22 ) groups may be replaced by NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, or O—CO, where
x is from 2 to 10, and
R 18 , R 19 , R 20 , R 21 , R 22 , R 30 , R 31 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl.
2. An organic light-emitting diode comprising at least one heteroleptic carbene complex according to claim 1 .
3. A device selected from the group consisting of stationary visual display units and mobile visual display units comprising at least one organic light-emitting diode according to claim 2 .
4. A light-emitting layer comprising at least one heteroleptic carbene complex according to claim 1 .
5. An organic light-emitting diode comprising an anode and a cathode and at least one light-emitting layer according to claim 4 between the anode and the cathode.
6. A device selected from the group consisting of stationary visual display units and mobile visual display units comprising at least one organic light-emitting diode according to claim 5 .
7. The organic light-emitting diode according to claim 5 , wherein the organic light-emitting diode further comprises a hole transporting layer between the anode and the light-emitting layer, wherein the hole transporting layer comprises a carbene complex.
8. The organic light-emitting diode according to claim 7 , wherein the carbene complex is a homoleptic carbene complex.
9. An organic light-emitting diode comprising an anode and a cathode and at least one light-emitting layer between the anode and the cathode, wherein the light-emitting layer comprises
and at least one heteroleptic carbene complex of the general formula (Ii) comprising two different carbene ligands (IIa) and (IIb),
wherein, in the ligand (IIa)
Do 1 is a donor atom selected from the group consisting of C, P, N, O, S and Si;
Do 2 is a donor atom selected from the group consisting of C, N, P, O and S;
r is 2 when Do 1 is C or Si, is 1 when Do 1 is N or P, and is 0 when Do 1 is O or S;
s is 2 when Do 2 is C, 1 when Do 2 is N or P, and is 0 when Do 2 is O or S;
X is a spacer selected from the group consisting of silylene, alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 13 , PR 14 , BR 15 , O, S, SO, SO 2 , CO, CO—O, O—CO and (CR 16 R 17 ) w , where one or more nonadjacent (CR 16 R 17 ) groups may be replaced by NR 13 , PR 14 , BR 15 , O, S, SO, SO 2 , CO, CO—O, or O—CO;
w is from 2 to 10;
R 13 , R 14 , R 15 , R 16 , and R 17 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl;
p is 0 or 1;
q is 0 or 1;
Y 1 and Y 2 are each independently hydrogen, a carbon group selected from the group consisting of alkyl, aryl, heteroaryl, alkynyl and alkenyl groups, or together form a bridge between the donor atom Do 1 and the nitrogen atom N which has at least two atoms, of which at least one is a carbon atom;
R 1 and R 2 are each independently hydrogen, an alkyl, an aryl, a heteroaryl, an alkynyl, an alkenyl, or R 1 and R 2 together form a bridge having a total of from three to five atoms, of which 1 to 5 atoms may be heteroatoms and the remaining atoms are carbon atoms, so that the group
forms a five- to seven-membered ring which optionally—in addition to the double bond already present—may have one further double bond or—in the case of a six- or seven-membered ring—two further double bonds, and may optionally be substituted by alkyl or aryl groups and/or groups with donor or acceptor action, and may optionally comprise at least one heteroatom, and the five- to seven-membered ring may optionally be fused to one or more further rings;
Y 1 and R 1 may be bonded to one another via a bridge, where the bridge is a group selected from the group consisting of alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, O—CO and (CR 21 R 22 ) x , where one or more nonadjacent (CR 21 R 22 ) groups may be replaced by NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, or O—CO, where
x is from 2 to 10;
R 18 , R 19 , R 20 , R 21 , R 22 , R 30 and R 31 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl;
R 3 is selected from the group consisting of hydrogen, an alkyl, aryl, heteroaryl, alkynyl and alkenyl radical; and
Y 3 is an alkyl radical;
wherein, in the carbene ligand (IIb)
Do 1 is a donor atom selected from the group consisting of C, P, N and Si;
Do 2 is a donor atom selected from the group consisting of C, N, P, O and S;
r is 2 when Do 1 is C or Si, is 1 when Do 1 is N or P;
s is 2 when Do 2 is C, 1 when Do 2 is N or P, and are each 0 when Do 2 is O or S;
X is a spacer selected from the group consisting of silylene, alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 13 , RP 14 , BR 15 , O, S, SO, SO 2 , CO, CO—O, O—CO and (CR 16 R 17 ), where one or more nonadjacent (CR 16 R 17 ) groups may be replaced by NR 13 , PR 14 , BR 15 , O, S, SO, SO 2 , CO, CO—O, or O—CO;
w is from 2 to 10;
R 13 , R 14 , R 15 , R 16 , and R 17 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl;
p is 0 or 1;
q is 0 or 1;
p′ is 0;
q′ is 0;
Y 1 and Y 2 are each independently hydrogen, a carbon group selected from the group consisting of alkyl, aryl, heteroaryl, alkynyl and alkenyl groups, or together form a bridge between the donor atom Do 1 and the nitrogen atom N which has at least two atoms, of which at least one is a carbon atom;
R 1 and R 2 are each independently hydrogen, an alkyl, an aryl, a heteroaryl, an alkynyl, an alkenyl, or R 1 and R 2 together form a bridge having a total of from three to five atoms, of which 1 to 5 atoms may be heteroatoms and the remaining atoms are carbon atoms, so that the group
forms a five- to seven-membered ring which optionally—in addition to the double bond already present—may have one further double bond or—in the case of a six- or seven-membered ring—two further double bonds, and may optionally be substituted by alkyl or aryl groups and/or groups with donor or acceptor action, and may optionally comprise at least one heteroatom, and the five- to seven-membered ring may optionally be fused to one or more further rings;
Y 1 and R 1 or Y 2 and R 1′ may be bonded to one another via a bridge where the bridge is a group selected from the group consisting of alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, O—CO and (CR 21 R 22 ) x , where one or more nonadjacent (CR 21 R 22 ) groups may be replaced by NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, or O—CO, where
x is from 2 to 10, and
R 18 , R 19 , R 20 , R 21 , R 22 , R 30 and R 31 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl;
R 3 is selected from the group consisting of hydrogen, an alkyl, aryl, heteroaryl, alkynyl and alkenyl radical;
Y 3 is a hydrogen, an alkyl, alkynyl, or alkenyl radical; and
in the carbene ligand (IIb) has the structure
wherein one occurrence of Z′ in an o-position relative to the bonding site with Do 1 is CH, the other occurrence of Z′ in an o-position relative to the bonding site with Do 1 is CR 12′ , each occurrence of Z′ in an m- or p-position relative to the bonding site with Do 1 is independently CR 12′ or N, provided 0 or only 1 Z′ is N, and
R 12′ in the Z′ groups are each independently selected from the group consisting of H, an alkyl, aryl, heteroaryl, alkynyl, alkenyl radical and a radical with donor or acceptor action, wherein 2 R 12′ radicals optionally form a fused ring, wherein the fused ring may optionally comprise at least one heteroatom;
wherein, the aromatic base of the structure
or one of the R 12′ radicals is optionally bonded to Y 2 via a bridge,
wherein the bridge is selected from the group consisting of alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, O—CO and (CR 21 R 22 ) x , where one or more nonadjacent (CR 21 R 22 ) groups may be replaced by NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, or O—CO, where
x is from 2 to 10; and
R 18 , R 19 , R 20 , R 21 , R 22 , R 30 , R 31 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl.
10. A device selected from the group consisting of stationary visual display units and mobile visual display units comprising at least one organic light-emitting diode according to claim 9 .
11. The organic light-emitting diode according to claim 9 , wherein the organic light-emitting diode further comprises a hole transporting layer between the anode and the light-emitting layer, wherein the hole transporting layer comprises a carbene complex.
12. The organic light-emitting diode according to claim 11 , wherein the carbene complex is a homoleptic carbene complex.
13. A light-emitting layer comprising
and at least one heteroleptic carbene complex of the general formula (Ii) comprising two different carbene ligands (IIa) and (IIb),
wherein, in the ligand (IIa)
Do 1 is a donor atom selected from the group consisting of C, P, N, O, S and Si;
Do 2 is a donor atom selected from the group consisting of C, N, P, O and S;
r is 2 when Do 1 is C or Si, is 1 when Do 1 is N or P, and is 0 when Do 1 is O or S;
s is 2 when Do 2 is C, 1 when Do 2 is N or P, and is 0 when Do 2 is O or S;
X is a spacer selected from the group consisting of silylene, alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 13 , RP 14 , BR 15 , O, S, SO, SO 2 , CO, CO—O, O—CO and (CR 16 R 17 ) w , where one or more nonadjacent (CR 16 R 17 ) groups may be replaced by NR 13 , PR 14 , BR 15 , O, S, SO, SO 2 , CO, CO—O, or O—CO;
w is from 2 to 10;
R 13 , R 14 , R 15 , R 16 and R 17 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl;
p is 0 or 1;
q is 0 or 1;
Y 1 and Y 2 are each independently hydrogen, a carbon group selected from the group consisting of alkyl, aryl, heteroaryl, alkynyl and alkenyl groups, or together form a bridge between the donor atom Do 1 and the nitrogen atom N which has at least two atoms, of which at least one is a carbon atom;
R 1 and R 2 are each independently hydrogen, an alkyl, an aryl, a heteroaryl, an alkynyl, an alkenyl, or R 1 and R 2 together form a bridge having a total of from three to five atoms, of which 1 to 5 atoms may be heteroatoms and the remaining atoms are carbon atoms, so that the group
forms a five- to seven-membered ring which optionally—in addition to the double bond already present—may have one further double bond or—in the case of a six- or seven-membered ring—two further double bonds, and may optionally be substituted by alkyl or aryl groups and/or groups with donor or acceptor action, and may optionally comprise at least one heteroatom, and the five- to seven-membered ring may optionally be fused to one or more further rings;
Y 1 and R 1 may be bonded to one another via a bridge, where the bridge is a group selected from the group consisting of alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, O—CO and (CR 21 R 22 ) x , where one or more nonadjacent (CR 21 R 22 ) groups may be replaced by NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, or O—CO, where
x is from 2 to 10;
R 18 , R 19 , R 20 , R 21 , R 22 , R 30 and R 31 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl;
R 3 is selected from the group consisting of hydrogen, an alkyl, aryl, heteroaryl, alkynyl and alkenyl radical; and
Y 3 is an alkyl radical;
wherein, in the carbene ligand (IIb)
Do 1 is a donor atom selected from the group consisting of C, P, N and Si;
Do 2 is a donor atom selected from the group consisting of C, N, P, O and S;
r is 2 when Do 1 is C or Si, is 1 when Do 1 is N or P;
s is 2 when Do 2 is C, 1 when Do 2 is N or P, and are each 0 when Do 2 is O or S;
X is a spacer selected from the group consisting of silylene, alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 13 , PR 14 , BR 15 , O, S, SO, SO 2 , CO, CO—O, O—CO and (CR 16 R 17 ) w , where one or more nonadjacent (CR 16 R 17 ) groups may be replaced by NR 13 , PR 14 , BR 15 , O, S, SO, SO 2 , CO, CO—O, or O—CO;
w is from 2 to 10;
R 13 , R 14 , R 15 , R 16 , and R 17 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl;
p is 0 or 1;
q is 0 or 1;
p′ is 0;
q′ is 0;
Y 1 and Y 2 are each independently hydrogen, a carbon group selected from the group consisting of alkyl, aryl, heteroaryl, alkynyl and alkenyl groups, or together form a bridge between the donor atom Do 1 and the nitrogen atom N which has at least two atoms, of which at least one is a carbon atom;
R 1 and R 2 are each independently hydrogen, an alkyl, an aryl, a heteroaryl, an alkynyl, an alkenyl, or R 1 and R 2 together form a bridge having a total of from three to five atoms, of which 1 to 5 atoms may be heteroatoms and the remaining atoms are carbon atoms, so that the group
forms a five- to seven-membered ring which optionally—in addition to the double bond already present—may have one further double bond or—in the case of a six- or seven-membered ring—two further double bonds, and may optionally be substituted by alkyl or aryl groups and/or groups with donor or acceptor action, and may optionally comprise at least one heteroatom, and the five- to seven-membered ring may optionally be fused to one or more further rings;
Y 1 and R 1 or Y 2 and R 1′ may be bonded to one another via a bridge where the bridge is a group selected from the group consisting of alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, O—CO and (CR 21 R 22 ) x , where one or more nonadjacent (CR 21 R 22 ) groups may be replaced by NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, or O—CO, where
x is from 2 to 10, and
R 18 , R 19 , R 20 , R 21 , R 22 , R 30 and R 31 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl;
R 3 is selected from the group consisting of hydrogen, an alkyl, aryl, heteroaryl, alkynyl and alkenyl radical;
Y 3 is a hydrogen, an alkyl, alkynyl, or alkenyl radical; and
in the carbene ligand (IIb) has the structure
wherein one occurrence of Z′ in an o-position relative to the bonding site with Do 1 is CH, the other occurrence of Z′ in an o-position relative to the bonding site with Do 1 is CR 12′ , each occurrence of Z′ in an m- or p-position relative to the bonding site with Do 1 is independently CR 12′ or N, provided 0 or only 1 Z′ is N, and
R 12′ in the Z′ groups are each independently selected from the group consisting of H, an alkyl, aryl, heteroaryl, alkynyl, alkenyl radical and a radical with donor or acceptor action, wherein 2 R 12′ radicals optionally form a fused ring, wherein the fused ring may optionally comprise at least one heteroatom;
wherein, the aromatic base of the structure
or one of the R 12′ radicals is optionally bonded to Y 2 via a bridge,
wherein the bridge is selected from the group consisting of alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 18 , PR 19 , BR 20 , S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, O—CO and (CR 21 R 22 ) x , where one or more nonadjacent (CR 21 R 22 ) groups may be replaced by NR 18 , PR 19 , BR 20 , O, S, SO, SO 2 , SiR 30 R 31 , CO, CO—O, or O—CO, where
x is from 2 to 10; and
R 18 , R 19 , R 20 , R 21 , R 22 , R 30 , R 31 are each independently selected from the group consisting of H, alkyl, aryl, heteroaryl, alkenyl, and alkynyl.
14. An organic light-emitting diode comprising an anode and a cathode and at least one light-emitting layer according to claim 13 between the anode and the cathode.
15. A device selected from the group consisting of stationary visual display units and mobile visual display units comprising at least one organic light-emitting diode according to claim 14 .
16. The organic light-emitting diode according to claim 14 , wherein the organic light-emitting diode further comprises a hole transporting layer between the anode and the light-emitting layer, wherein the hole transporting layer comprises a carbene complex.
17. The organic light-emitting diode according to claim 16 , wherein the carbene complex is a homoleptic carbene complex.