Delayed-fluorescence material and organic electroluminescence element using same

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

wherein, in the general formula (1′), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 each independently represent a hydrogen atom or an electron-donating group, and at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 or R 8 is an electron-donating group that contains a structure represented by the following D9:

and R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 and R 16 each independently represent a hydrogen atom or an electron-withdrawing group, and at least one of R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 or R 16 is an electron-withdrawing.

2. The compound according to claim 1 , provided that when R 4 is an electron-donating group that contains a structure represented by the general formula (2), R 12 is a hydrogen atom:

wherein, in the general formula (2), Z 1 represents an oxygen atom or a silicon atom, and may form, each independently at A 1 and A 2 , an aromatic ring, a heteroaromatic ring, an aliphatic ring or a nonaromatic hetero ring.

3. An organic electroluminescence element having an anode, a cathode, and at least one organic layer containing a light-emitting layer between the anode and the cathode, wherein the light-emitting layer contains a host material, and a compound according to claim 1 , which radiates delayed fluorescence.

4. In an organic electroluminescence display device comprising an organic electroluminescence element, wherein the improvement comprises the organic electroluminescence element is in accordance with claim 3 .

5. The organic electroluminescence element according to claim 3 wherein R 4 and R 12 are both hydrogen.

6. The organic electroluminescent element of claim 5 , wherein, in the general formula (1′), at least one of R 2 or R 7 is an electron-donating group.

7. The organic electroluminescent element of claim 3 , wherein, in the general formula (1′), at least one of R 10 or R 15 is an electron-withdrawing group.

8. The organic electroluminescence element according to claim 3 , wherein at least two of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 in the general formula (1′) each are an electron-donating group.

9. The organic electroluminescence element according to claim 3 , wherein, in the general formula (1′), at least one of R 1 , R 2 , R 3 or R 4 is an electron-donating group, and at least one of R 5 , R 6 , R 7 or R 8 is an electron-donating group.

10. The organic electroluminescence element according to claim 3 , wherein, in the general formula (1′), at least one of R 2 or R 3 is an electron-donating group, and at least one of R 6 or R 7 is an electron-donating group.

11. The organic electroluminescence element according to claim 3 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 or R 8 is an electron-donating group other than D9 that contains a structure represented by any of the following general formulae (2) to (4):

wherein, in the general formula (2), Z 1 represents a nitrogen atom, an oxygen atom, a sulfur atom or a silicon atom, and may form, each independently at A 1 and A 2 , an aromatic ring, a heteroaromatic ring, an aliphatic ring or a nonaromatic hetero ring; in the general formula (3), R 20 represents a hydrogen atom, an aryl group or an atomic group necessary for forming the ring structure represented by A 4 , and may form, each independently as A 3 and A 4 , a heteroaromatic ring or a nonaromatic hetero ring; in the general formula (4), Z 2 , Z 3 , Z 4 and Z 5 each independently represent an oxygen atom or a sulfur atom.

12. The organic electroluminescence element according to claim 3 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 or R 8 is an electron donating group that contains a structure of any of the following D1, D2, D3, D4, D5, D6, D7, D8, or D10:

13. The organic electroluminescence element according to claim 12 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 or R 8 is an electron-donating group that contains a structure represented by the above D3.

14. The organic electroluminescence element according to claim 3 , wherein at least two of R 9 , R 10 , R 11 , R 2 , R 13 , R 14 , R 15 and R 16 in the general formula (1′) each are an electron-withdrawing group.

15. The organic electroluminescence element according to claim 3 , wherein, in the general formula (1′), at least one of R 9 , R 10 , R 11 or R 12 is an electron withdrawing group, and at least one of R 13 , R 14 , R 15 or R 16 is an electron-withdrawing group.

16. The organic electroluminescence element according to claim 3 , wherein, in the general formula (1′), R 10 or R 11 is an electron-withdrawing group, and R 14 or R 15 is an electron-withdrawing group.

17. The organic electroluminescence element according to claim 3 , wherein, in the general formula (1′), R 10 or R 11 is a cyano group, and R 14 or R 15 is a cyano group.