Organic electroluminescent 3,6-disubstituted carbazole compounds and organic electroluminescent device including the same

A compound of Formula (I):

• wherein
• X1 and X2 are each independently O or S;
• R1, R2, R3, R4, R5, R6, R7, and R8 are each independently selected from —H, deuterium, halo, cyano, alkyl, aryl, heteroaryl, cycloalkyl, and heterocyclyl, wherein R1, R2, R3, R4, R5, R6, R7, and R8 are optionally substituted with one or more substituents selected from the group consisting of deuterium, halo, cyano, nitro, hydroxyl, silyl, alkyl, cycloalkyl, alkoxy, alkenyl, aryl, and heterocyclyl, and wherein R1, R2, R3, R4, R5, R6, R7, and R8 are optionally bonded to each other or joined to one or more adjacent substituents to form a monocyclic or polycyclic group optionally containing one or more heteroatoms selected from N, S, and O;
• L is a bond, arylene, or heteroarylene;
• n is 0, 1, 2, or 3,
• Ar is aryl, heteroaryl, fluorenyl, cycloalkyl, or heterocyclyl, and
• m is 1, 2, or 3.