Tetraarylborate compound, catalyst composition comprising same, and method for preparing ethylene homopolymers or copolymers of ethylene and a-olefin by using same

A tetraarylborate compound represented by Formula 1:

• wherein
• B is a boron atom;
• Ar1 is (C6-C30) aryl, wherein the aryl of Ar1 may be further substituted by one or more substituents selected from the group consisting of (C1-C30) alkyl, halo (C1-C30) alkyl, and (C6-C30) aryl (C1-C30) alkyl;
• Ar2 is fluorine-substituted (C6-C30) aryl;
• R1 is hydrogen or (C1-C30) alkyl;
• and
• R2 is (C1-C30) alkyl, or R2 and R1 are optionally linked to each other to form a ring, wherein the ring may be further substituted by one or more substituents selected from the group consisting of (C1-C30) alkyl, (C1-C30) alkoxy, halo (C1-C30) alkyl, (C3-C30) cycloalkyl, (C1-C30) alkyl (C6-C30) aryl, (C6-C30) aryl, (C6-C30) aryloxy, (C1-C30) alkyl (C6-C30) aryloxy, (C6-C30) aryl (C1-C30) alkyl, and ((C1-C30) alkyl (C6-C30) aryl) (C1-C30) alkyl.