Luminescent material for delayed fluorescence and organic electroluminescent device comprising the same

1. An organic electroluminescent device comprising a luminescent material for delayed fluorescence comprising a compound of the following formula 1 as a dopant material, and further comprising a compound of the following formula 8 as a host material:

wherein

R 1 represents a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, a substituted or unsubstituted (C5-C30)aryl, a substituted or unsubstituted 5- to 30-membered heteroaryl, or CN; or may be linked to an adjacent substituent to form a substituted or unsubstituted mono- or polycyclic, (C5-C30) alicyclic or aromatic ring, whose carbon atom(s) may be replaced with at least one heteroatom selected from nitrogen, oxygen, sulfur, Si, PO, SO, SO 2 , and SeO 2 ;

X 1 represents —CR 3 or N;

X 2 represents —CR 6 or N;

R 3 and R 6 each independently represent hydrogen, deuterium, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, a substituted or unsubstituted (C5-C30)aryl, a substituted or unsubstituted 5- to 30-membered heteroaryl, or CN; or may be linked to an adjacent substituent to form a substituted or unsubstituted mono- or polycyclic, (C5-C30) alicyclic or aromatic ring, whose carbon atom(s) may be replaced with at least one heteroatom selected from nitrogen, oxygen, sulfur, Si, PO, SO, SO 2 , and SeO 2 ;

E is represented by the following formulae 2-1 to 2-5, 2-9 to 2-13, 2-15, 2-19 to 2-28, 2-30, and 2-32 to 2-35;

wherein

X and Y each independently are selected from O, S, NR 4 , Si(R 4 ) 2 , C(R 4 ) 2 , PO(R 4 ) 2 , SO, SO 2 , and SeO 2 ;

R 4 represents a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C5-C30)aryl, or a substituted or unsubstituted 5- to 30-membered heteroaryl; where there are two R 4 's, each of the two R 4 's may be the same or different, and the two R 4 's may be linked to each other to form a substituted or unsubstituted 11- to 60-membered polycyclic ring; and

R each independently represents hydrogen, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C5-C30)aryl, or a substituted or unsubstituted 5- to 30-membered heteroaryl; and

* represents a bonding site between the ring comprising X 1 and X 2 , and E;

independently represents N or CR 11 ;

R 11 independently represents hydrogen, deuterium, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, a substituted or unsubstituted (C5-C30)aryl, a substituted or unsubstituted 5- to 30-membered heteroaryl, or CN; or may be linked to an adjacent substituent to form a substituted or unsubstituted mono- or polycyclic, (C5-C30) alicyclic or aromatic ring, whose carbon atom(s) may be replaced with at least one heteroatom selected from nitrogen, oxygen, sulfur, Si, PO, SO, SO 2 , and SeO 2 ;

Het represents a 5- to 30-membered heteroaryl(ene);

L represents hydrogen, a substituted or unsubstituted (C5-C30)aryl, or a substituted or unsubstituted 5- to 30-membered heteroaryl; or may be linked to an adjacent substituent to form a substituted or unsubstituted mono- or polycyclic, (C5-C30) alicyclic or aromatic ring, whose carbon atom(s) may be replaced with at least one heteroatom selected from nitrogen, oxygen, sulfur, Si, PO, SO, SO 2 , and SeO 2 ;

i represents an integer of 1 or 2; and

j represents an integer of 1 to 5; where j is an integer of 2 or more, each of L may be the same or different.

2. The organic electroluminescent device comprising the luminescent material for delayed fluorescence according to claim 1 , wherein formula 1 is selected from the following formulas 1-1 to 1-16:

wherein

Z is selected from O, S, NR 8 , Si(R 8 ) 2 , C(R 8 ) 2 , PO(R 8 ) 2 , SO, SO 2 , and SeO 2 ;

R 8 represents a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C5-C30)aryl, or a substituted or unsubstituted 5- to 30-membered heteroaryl; and

Ph represents phenyl, and E is as defined in claim 1 .

3. The organic electroluminescent device comprising the luminescent material for delayed fluorescence according to claim 1 , wherein the compound represented by formula 1 is selected from the group consisting of:

4. The organic electroluminescent device according to claim 1 , wherein the compound represented by formula 8 is represented by the following formula 9:

wherein

X 11 independently represents N or CR 11 ;

X 12 independently represents N or CR 12 ;

R 11 and R 12 each independently represent hydrogen, deuterium, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, a substituted or unsubstituted (C5-C30)aryl, a substituted or unsubstituted 5- to 30-membered heteroaryl, or CN; or may be linked to an adjacent substituent to form a substituted or unsubstituted mono- or polycyclic, (C5-C30) alicyclic or aromatic ring, whose carbon atom(s) may be replaced with at least one heteroatom selected from nitrogen, oxygen, sulfur, Si, PO, SO, SO 2 , and SeO 2 ; and

L independently represents hydrogen, a substituted or unsubstituted (C5-C30)aryl, or a substituted or unsubstituted 5- to 30-membered heteroaryl; or may be linked to an adjacent substituent to form a substituted or unsubstituted mono- or polycyclic, (C5-C30) alicyclic or aromatic ring, whose carbon atom(s) may be replaced with at least one heteroatom selected from nitrogen, oxygen, sulfur, Si, PO, SO, SO 2 , and SeO 2 .

5. The organic electroluminescent device according to claim 4 , wherein X 12 independently represents N or CH.

6. The organic electroluminescent device according to claim 1 , wherein the compound represented by formula 8 is selected from the group consisting of: