A theoretical study of the comonomer effect in the ethylene polymerization with zirconocene catalytic systems

Copolymerization of ethylene/unsaturated alcohols using nickel catalysts: effect of the ligand on the activity and comonomer incorporation

“…These results are in accordance with the tendency found in the literature [10][11][12][13] to consider that quantum-chemical calculations are able to help in the understanding of the processes involved and even on the screening of catalysts.…”

“…The molecular weight of a sample of PE obtained with the system 3-NiBr 2 /MAO under similar experimental conditions, except that a higher Al/Ni was used (Al/Ni = 2200) was found to be higher than that of sample R 66 (M n = 41.1 and PD = 3.5) [8]. Table 8 Number of branches of polyethylene samples determined by 13 the catalyst precursors were activated by MAO and H was protected with TMA. Fig.…”

“…Although the absolute values computed by the two models, PM3 and B3LYP/6-31G** are considerably different, as it would be expected since PM3 is known not to give very reliable absolute energy values, although it gives good estimates of the geometry [13,23], the relative order is the same.…”

“…Theoretical calculations have been used increasingly to elucidate the steps involved in the polymerization and copolymerization processes [9][10][11][12][13][14].…”

Ethylene polymerization reactions with Ziegler-Natta catalysts. II. Ethylene polymerization reactions in the presence of deuterium

“…[2][3][4][5][6] However, such an interaction involving a CH 2 group can only result in the uniform reduction of the propagation rate whereas a specific ␤-agostic interaction in a TiOC 2 H 5 species rationalizes the numerous kinetic effects described in the preceding article.…”