Modeling study on the catalytic activities of 2-imino-1,10-phenanthrolinylmetal (Fe, Co, and Ni) precatalysts in ethylene oligomerization†
In experiments, transition metal complex systems ligated with the same ligand showed significantly different catalytic activities towards ethylene oligo/polymerization. In this study, the variations of catalytic activities were investigated for series of 2-imino-1,10-phenanthrolinylmetal (Fe, Co and Ni) complexes. Their catalytic activities were evaluated by the multiple linear regression analysis (MLRA). The calculated activities are well consistent with the experimental data, reflecting by the correlation coefficient values (R2) for most of systems over 0.98. With regard to the influence of the analogue structure on the change of catalytic activities, the MLRA model was modified through using the variation of catalytic activities as response variable and the change of parameters as independent variable. The calculated variation of reaction activities present very good correlation with experimental results with R2 value closing to 1.0, whereas, the correlation results are relatively low for analogues with different metal atoms. Additionally, the contributions from electronic and steric effects were analyzed to explain the reason for variations of the activities.