Cyclopenta[b]fluorenyl transition metal compound, catalyst composition containing the same, and method of preparing ethylene homopolymer or copolymer of ethylene and alpha-olefin using the same

A compound of chemical formula 12:

• In Chemical Formula 12,
• R1 is hydrogen, (C1-C50)alkyl, halo(C1-C50)alkyl, (C3-C50)cycloalkyl, (C6-C30)aryl, (C6-C30)aryl(C1-C50)alkyl, ((C1-C50)alkyl(C6-C30)aryl)(C1-C50)alkyl, —NRaRb, —SiRcRdRe, or 5- through 7-membered N-heterocycloalkyl containing at least one nitrogen atom;
• R2 and R3 each are independently hydrogen, (C1-C50)alkyl, (C1-C50)alkoxy, halo(C1-C50)alkyl, (C3-C50)cycloalkyl, (C6-C30)aryl, (C6-C30)aryloxy, (C1-C50)alkyl(C6-C30)aryloxy, (C6-C30)aryl(C1-C50)alkyl, ((C1-C50)alkyl(C6-C30)aryl)(C1-C50)alkyl, —NRaRb or —SiRcRdRe;
• R4 and R5 each are independently (C1-C50)alkyl, halo(C1-C50)alkyl, (C3-C50)cycloalkyl, (C6-C30)aryl, (C6-C30)aryl(C1-C50)alkyl, ((C1-C50)alkyl(C6-C30)aryl)(C1-C50)alkyl, —NRaRb, or —SiRcRdRe;
• R6, R7, R8 and R9 each are independently hydrogen, (C1-C50)alkyl, halo(C1-C50)alkyl, (C3-C50)cycloalkyl, (C1-C50)alkoxy, (C6-C30)aryl, (C6-C30)aryl(C1-C50)alkyl, ((C1-C50)alkyl(C6-C30)aryl)(C1-C50)alkyl, (C6-C30)aryloxy, (C1-C50)alkyl(C6-C30)aryloxy, N-carbazolyl, —NRaRb, or —SiRcRdRe, or may be linked to an adjacent substituent via (C1-C5)alkylene to form a ring, and at least one —CH2— of the alkylene may be substituted by a hetero atom selected from —O—, —S—, and —NR′—, and the alkylene may be further substituted with (C1-C50)alkyl;
• aryl of R1 to R9 may be further substituted with at least one substituent selected from the group consisting of (C1-C50)alkyl, halo(C1-C50)alkyl, (C1-C50)alkoxy, (C6-C30)aryloxy, (C6-C30)aryl, (C1-C50)alkyl(C6-C30)aryl, and (C6-C30)aryl(C1-C50)alkyl;
• R′ and Ra to Re each are independently (C1-C50)alkyl or (C6-C30)aryl;
• n is an integer of 1 or 2, each R1 may be the same or different when n is 2;
• provided that there is excluded a case where all of R1, R2, R3, R6, R7, R8, and R9 are hydrogen.