1-octene composition

A method of preparing 1-octene composition, the method comprising the step of multimerizing ethylene in the presence of a catalyst system for olefin oligomerization comprising a ligand compound, a transition metal source, and a cocatalyst,

• the 1-octene composition comprising 90% by weight or more of 1-octene and 0.01 to 10% by weight of three or more of compounds represented by the following Chemical Formulae 1 to 4:
• wherein the ligand compound comprises i) two or more of a group represented by the following Chemical Formula 5 in the molecule, in which the two or more of the group are linked via four carbon atoms by a group selected from the group consisting of an aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 3 to 20 carbon atoms, and an aromatic group having 6 to 20 carbon atoms, or is ii) a compound represented by the following Chemical Formula 6,
• wherein R1 to R4 are each independently C1-20 alkyl, C2-20 alkenyl, C6-20 aryl, C7-20 arylalkyl, C7-20 alkylaryl, or C7-20 alkoxyaryl,
• wherein R5 to R8 are each independently C6-20 aryl, or C7-20 alkylaryl,
• R9 and R10 are each independently C1-20 alkyl, with the proviso that R9 and R10 are not the same as each other,
• R11 to R13 are each independently hydrogen, C1-20 alkyl, C2-20 alkenyl, C7-20 arylalkyl, C7-20 arylalkenyl, C3-20 cycloalkyl, C3-20 cycloalkenyl, C9-20 arylcycloalkyl, C9-20 arylcycloalkenyl, C6-20 aryl, or C7-20 alkylaryl.