Organic electroluminescent compound and organic electroluminescent device comprising the same

1. An organic electroluminescent compound comprising ligand L 1 represented by the following formula 1, wherein the ligand L 1 is coordinated to a metal having an atomic number greater than 40:

wherein

R 1 to R 3 , each independently, represent hydrogen, deuterium, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; or adjacent R 1 's, adjacent R 2 's, and adjacent R 3 's, each independently, may be linked to each other to form a ring(s), and

a represents an integer of 1 to 5, b represents an integer of 1 to 4, and c represents an integer of 1 to 3, in which, if a to c, each independently, are an integer of 2 or more, each of R 1 , each of R 2 , and each of R 3 may be the same or different.

2. The organic electroluminescent compound according to claim 1 , wherein the organic electroluminescent compound is represented by the following formula 2:

M(L 1 ) x (L 2 ) y (L 3 ) z   (2)

wherein

M represents a metal having an atomic number greater than 40;

x represents 1, 2, or 3;

y represents 0, 1, or 2;

z represents 0, 1, or 2;

the sum of x, y, and z is the oxidation number of the M;

L 1 represents the ligand represented by formula 1;

L 2 represents the ligand represented by the following formula 3; and

L 3 represents the ligand represented by the following formula 4:

wherein

R 4 to R 8 , each independently, represent hydrogen, deuterium, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; or R 4 and R 5 , R 5 and R 6 , adjacent R 7 's, and adjacent R 8 's, each independently, may be linked to each other to form a ring(s); and

d and e, each independently, represent an integer of 1 to 4, in which, if d and e, each independently, are an integer of 2 or more, each of R 7 and each of R 8 may be the same or different.

3. The organic electroluminescent compound according to claim 1 , wherein the metal having an atomic number greater than 40 is Ir or Pt.

4. The organic electroluminescent compound according to claim 1 , wherein the organic electroluminescent compound is represented by the following formula 5:

wherein

R 4 to R 6 , each independently, represent hydrogen, deuterium, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; or R 4 and R 5 , and R 5 and R 6 , each independently, may be linked to each other to form a ring(s); and

R 1 to R 3 and a to c are as defined in claim 1 .

5. The organic electroluminescent compound according to claim 2 , wherein R 1 to R 8 , each independently, represent hydrogen, deuterium, a (C1-C10)alkyl unsubstituted or substituted with deuterium(s), or an unsubstituted (C6-C25)aryl.

6. The organic electroluminescent compound according to claim 2 , wherein R 1 to R 8 , each independently, are selected from the group consisting of hydrogen, deuterium, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, neopentyl, isopentyl, sec-pentyl, 3-pentyl, and phenyl.

7. The organic electroluminescent compound according to claim 2 , wherein the formula 3 is represented by any one selected from the group consisting of the following:

8. The organic electroluminescent compound according to claim 1 , wherein the organic electroluminescent compound is selected from the following:

9. An organic electroluminescent material comprising the organic electroluminescent compound according to claim 1 .

10. An organic electroluminescent device comprising an anode, a cathode, and a light-emitting layer between the anode and the cathode, wherein the light-emitting layer comprises the organic electroluminescent compound according to claim 1 .