Organic electroluminescent compound and organic electroluminescent device comprising the same

A compound comprising a ligand having the structure represented by the following formula 1, wherein the ligand is coordinated to a metal having an atomic number greater than 40:

• wherein
• ring A represents an N-containing 10-membered heteroaryl ring which may be substituted with R2;
• ring B represents a (C6-C18)aryl ring which may be substituted with R3;
• R1 to R3, each independently, represent 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 each of R1 to R3 may be linked to each other to form a ring;
• and
• a to c, each independently, represent an integer of 0 to 4, where if a to c, each independently, are an integer of 2 or more, each of R1 to R3 may be the same or different.