Indole derivative, material for light-emitting device and light-emitting device using the same

1. A compound represented by the following formula (II):

wherein L 12 represents one of a from 2- to 6-valent connecting group having a heteroaryl group and a from 2- to 6-valent connecting group comprising a non-conjugate connecting group having an arylene group; n 2 represents an integer of from 2 to 6; R represents one of an alkyl group having from 1 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, a heteroaryl group having from 2 to 20 carbon atoms and a silyl group having from 3 to 20 carbon atoms; and m represents an integer of from 0 to 6.

2. A light-emitting device comprising:

a pair of electrodes formed on a substrate; and

at least one organic compound layer containing a light-emitting layer provided between the electrodes,

wherein the at least one organic compound layer comprises at least one compound represented by the following formula (II):

wherein L 12 represents one of a from 2- to 6-valent connecting group having a heteroaryl group and a from 2- to 6-valent connecting group comprising a non-conjugate connecting group having an arylene group; n 2 represents an integer of from 2 to 6; R represents one of an alkyl group having from 1 to 20 carbon atoms, an aryl group having from 6 to 20 carbon atoms, a heteroaryl group having from 2 to 20 carbon atoms and a silyl group having from 3 to 20 carbon atoms; and m represents an integer of from 0 to 6.

3. The light-emitting device of claim 2 , wherein the light-emitting layer comprises the at least one compound represented by the formula (II) and at least one luminescent material.

4. The light-emitting device of claim 3 , wherein the luminescent material is a transition metal complex.

5. The light-emitting device of claim 4 , wherein the transition metal complex is capable of generating luminescence by a transition from a triplet excitation state thereof.

6. The light-emitting device of claim 2 , wherein the light-emitting layer comprises a high molecular compound.

7. The light-emitting device of claim 2 , wherein the light-emitting layer has a thickness of from 1 nm to 5 μm.

8. The light-emitting device of claim 4 , wherein the transition metal complex is an ortho-metalated metal complex.

9. The light-emitting device of claim 4 , wherein the transition metal complex is an ortho-metalated iridium complex.

10. The light-emitting device of claim 3 , wherein the at least one compound represented by the formula (II) is from 0.1 to 95% by weight based on the luminescent material.

11. The compound of claim 1 , wherein the heteroaryl group in L 12 is selected from the group consisting of pyridine, piperidine, pyrazine, triazine, thiophene, quinoline and quinoxaline, when L 12 represents one of a from 2- to 6-valent connecting group having a heteroaryl group.

12. The compound of claim 11 , wherein the heteroaryl group in L 12 is selected from the group consisting of pyridine, piperidine, pyrazine and triazine.

13. The compound of claim 1 , wherein the arylene group in L 12 is selected from the group consisting of phenylene, naphthylene, anthracenylene, phenanthrylene, pyrenylene and triphenylene, when L 12 represents one of a from 2- to 6-valent connecting group comprising a non-conjugate connecting group having an arylene group.

14. The compound of claim 13 , wherein the aryl group in L 12 is phenylene.

15. The compound of claim 1 , wherein the non-conjugate connecting group in L 12 is selected from the group consisting of an arylene group bonded at a meta position, an alkylene group, a silyl group, —O— and —N═.

16. The compound of claim 1 , wherein L 12 is selected from the group consisting of:

wherein p represents 1 to 500.

17. The compound of claim 1 , wherein n 2 is 2.

18. The compound of claim 1 , wherein n 2 is 3.