Material for organic electroluminescent elements, and organic electroluminescent element using same
View Patent ↗Provided are an organic electroluminescent device (organic EL device) that is improved in luminous efficacy, sufficiently secures driving stability, and has a simple construction, and a material for organic EL devices to be used in the organic EL device. The material for organic EL devices is a material for organic EL devices formed of an ortho-carborane compound having a structure in which a silyl group (—SiR 3 ) is bonded to a divalent ortho-carborane group represented by C 2 B 10 H 10 through an aromatic group. In addition, the organic electroluminescent device is an organic electroluminescent device having a structure in which an anode, an organic layer, and a cathode are laminated on a substrate, the device having an organic layer containing the ortho-carborane compound, and the organic layer being a light-emitting layer, an electron-transporting layer, a hole-blocking layer, or an exciton-blocking layer.
1. A material for organic electroluminescent devices, comprising an ortho-carborane compound represented by the general formula (1):
where ring A represents a divalent ortho-carborane group C 2 B 10 H 10 represented by the formula (1a), L 1 and L 2 each independently represent a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 carbon atoms, or a linked aromatic group formed by linking 2 to 6 aromatic rings selected from the aromatic hydrocarbon group and the aromatic heterocyclic group, when L 1 or L 2 represents the linked aromatic group, the group may be linear or branched, and the aromatic rings to be linked may be identical to or different from each other, and L 1 represents a p+1-valent group and L 2 represents a q+1-valent group, R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 each independently represent an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, R 7 and R 8 each independently represent hydrogen, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, p represents an integer of from 1 to 5, q represents an integer of from 0 to 5, and r represents an integer of from 1 to 4.
2. A material for organic electroluminescent devices according to claim 1 , wherein the ortho-carborane compound represented by the general formula (1) comprises an ortho-carborane compound represented by the general formula (2):
where L 1 , L 2 , R 1 to R 8 , p, q, and r are identical in meaning to those in the general formula (1).
3. A material for organic electroluminescent devices according to claim 2 , wherein in the general formula (2), L 1 and L 2 each independently represent a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a linked aromatic group formed by linking 2 to 6 aromatic rings selected from the aromatic hydrocarbon group and the aromatic heterocyclic group.
4. A material for organic electroluminescent devices according to claim 3 , wherein in the general formula (2), R 1 to R 6 each independently represent an aliphatic hydrocarbon group having 1 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms.
5. An organic electroluminescent device having a structure in which an anode, an organic layer, and a cathode are laminated on a substrate, wherein the organic layer comprises an organic layer containing the material for organic electroluminescent devices of claim 1 .
6. An organic electroluminescent device according to claim 5 , wherein the organic layer containing the material for organic electroluminescent devices comprises at least one layer selected from the group consisting of a light-emitting layer, an electron-transporting layer, a hole-blocking layer, and an exciton-blocking layer.
7. An organic electroluminescent device according to claim 5 , wherein the organic layer containing the material for organic electroluminescent devices comprises an electron-transporting layer, a hole-blocking layer, or an exciton-blocking layer.