Compound, composition and organic light-emitting device
A compound of formula (I) or (III) (Formulae (I), (III)) wherein: one Y is a substituent R 1 bound directly to the fluorene unit of formula (I) by an sp 3 -hybridised carbon atom; the other Y is an aryl or heteroaryl group Ar 1 that may be unsubstituted or substituted with one or more substituents; Ar 2 is an arylene or heteroarylene group; R 2 is a substituent; b is 0, 1, 2, 3 or 4; c is 0, 1, 2 or 3; and X is a group of formula (II): (Formula (II)) wherein Z is O or S; R 3 independently in each occurrence is a substituent; each x is independently 0, 1, 2 or 3; and * is a bond to the fluorene unit of formula (I). The compounds may be used as host materials for phosphorescent dopants in organic light-emitting devices.
1. A compound of formula (I)
wherein:
one Y is a substituent R 1 bound directly to the fluorene unit of formula (I) by an sp 3 -hybridised carbon atom, wherein R 1 is a C 1-20 alkyl group;
the other Y is a phenyl that may be unsubstituted or substituted with one or more substituents;
R 2 is a linear, branched or cyclic C 1-12 alkyl; or aryl or heteroaryl which is unsubstituted or substituted with one or more C 1-12 alkyl groups;
b is 0, 1, 2, 3 or 4;
c is 0, 1, 2 or 3; and
X is a group of formula (II):
wherein Z is O or S; R 3 independently in each occurrence is a substituent; each x is independently 0, 1, 2 or 3; and * is a bond to the fluorene unit of formula (I).
2. A compound according to claim 1 wherein the group of formula (II) has formula (IIa):
3. A compound according to claim 1 wherein the group of formula (II) has formula (IIb):
4. A composition comprising a compound according to claim 1 and at least one light-emitting dopant.
5. A composition according to claim 4 wherein the light-emitting dopant is a phosphorescent dopant.
6. A composition according to claim 5 wherein the light-emitting dopant is a blue light-emitting material.
7. A composition according to claim 6 wherein the light-emitting dopant is a metal complex comprising at least one unsubstituted or substituted phenylimidazole or phenyltriazole ligand.
8. A formulation comprising a compound according to claim 1 and one or more solvents.
9. An organic light-emitting device comprising an anode, a cathode and a light-emitting layer between the anode and the cathode wherein the light-emitting layer comprises a compound according to claim 1 .
10. An organic light-emitting device according to claim 9 wherein the organic light-emitting layer comprises a composition comprising the compound and at least one light-emitting dopant.
11. An organic light-emitting device comprising an anode, a cathode, a light-emitting layer between the anode and the cathode, and at least one further light-emitting layer, wherein the light-emitting layer comprises a compound of formula (I):
wherein:
one Y is a substituent R 1 bound directly to the fluorene unit of formula (I) by an sp 3 -hybridised carbon atom;
the other Y is a phenyl that may be unsubstituted or substituted with one or more substituents;
R 2 is a linear, branched or cyclic C 1-12 alkyl; or aryl or heteroaryl which is unsubstituted or substituted with one or more C 1-12 alkyl groups;
b is 0, 1, 2, 3 or 4;
c is 0, 1, 2 or 3; and
X is a group of formula (II):
wherein Z is O or S; R 3 independently in each occurrence is a substituent; each x is independently 0, 1, 2 or 3; and * is a bond to the fluorene unit of formula (I).
12. An organic light-emitting device comprising an anode, a cathode and a light-emitting layer between the anode and the cathode, wherein the device emits white light, and wherein the light-emitting layer comprises a compound of formula (I):
wherein:
one Y is a substituent R 1 bound directly to the fluorene unit of formula (I) by an sp 3 -hybridised carbon atom;
the other Y is a phenyl that may be unsubstituted or substituted with one or more substituents;
R 2 is a linear, branched or cyclic C 1-12 alkyl; or aryl or heteroaryl which is unsubstituted or substituted with one or more C 1-12 alkyl groups;
b is 0, 1, 2, 3 or 4;
c is 0, 1, 2 or 3; and
X is a group of formula (II):
wherein Z is O or S; R 3 independently in each occurrence is a substituent; each x is independently 0, 1, 2 or 3; and * is a bond to the fluorene unit of formula (I).
13. A method of forming an organic light-emitting device according to claim 9 comprising the step of forming the light-emitting layer over one of the anode and the cathode and forming the other of the anode and the cathode over the light-emitting layer.
14. A method according to claim 13 wherein the light-emitting layer is formed by depositing a formulation comprising the compound and one or more solvents and evaporating the one or more solvents.
15. An organic light-emitting device comprising an anode, a cathode and a light-emitting layer between the anode and the cathode wherein the light-emitting layer comprises a composition comprising at least one light-emitting dopant and a compound of formula (I)
wherein:
one Y is a substituent R 1 bound directly to the fluorene unit of formula (I) by an sp 3 -hybridised carbon atom;
the other Y is an aryl or heteroaryl group Ar 1 that may be unsubstituted or substituted with one or more substituents;
R 2 is a substituent;
b is 0, 1, 2, 3 or 4;
c is 0, 1, 2 or 3; and
X is a group of formula (II):
wherein Z is O or S; R 3 independently in each occurrence is a substituent; each x is independently 0, 1, 2 or 3; and * is a bond to the fluorene unit of formula (I);
wherein the device comprises at least one further light-emitting layer.
16. The compound according to claim 1 wherein b and c are each 0.
17. The organic light-emitting device according to claim 11 wherein b and c are each 0.
18. The organic light-emitting device according to claim 12 wherein b and c are each 0.