Provided are a ligand compound having Formula 1, which exhibits high catalytic activity while exhibiting high 1-hexene and 1-octene selectivity, thereby allowing ethylene oligomerization to be achieved with excellent efficiency, an organic chromium compound, a catalyst composition including the organic chromium compound, and a method for oligomerizing ethylene by using the same;

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A machine learning model predicts a K value for a new iron ethylene oligomerization catalyst structure, where the K value has not yet been experimentally determined.

Phosphino-quinoline-pyridine ligands and compositions that include complexes, the complexes including a phosphino-quinoline-pyridine ligand and a metal coordinated to the ligand are disclosed. Methods of oligomerization, such as methods of oligomerizing alpha-olefins, performed in the presence of a complex that includes a phosphino-quinoline-pyridine ligand are also disclosed.

A machine learning model predicts a K value for a new iron ethylene oligomerization catalyst structure, where the value has not yet been experimentally determined.