2 research outputs found
Tailoring Polyethylenes by Nickel Complexes Bearing Modified 1‑(2-BenzhydrylÂnaphthylimino)-2-phenyliminoÂacenaphthylene Derivatives
A series of 1-(2-benzhydrylÂnaphthylimino)-2-phenyliminoÂacenaphthylene
derivatives (<b>L1</b>–<b>L5</b>) was synthesized,
characterized, and then reacted with (DME)ÂNiBr<sub>2</sub> to form
the corresponding [1-(2-benzhydrylÂnaphthylimino)-2-phenyliminoÂacenaphthyl]Ânickel
bromides (<b>C1</b>–<b>C5</b>). All nickel complexes
were fully characterized by their FT-IR spectra and elemental analysis.
The molecular structures of the representative complexes <b>C1</b> and <b>C4</b> were also determined by single-crystal X-ray
diffraction. On activation with either methylaluminoxane (MAO) or
diethylaluminum chloride (Et<sub>2</sub>AlCl), all title nickel complexes
showed high activities toward ethylene polymerization; the resulting
polyethylenes showed molecular weights higher than those obtained
by using the nickel analogues bearing (2-benzhydrylÂnaphthylimino)Âpyridines
and also had branches lower than those obtained by using other diiminoacenaphthylnickel
analogues. Therefore, the modification of ligands could affect the
catalytic behavior of their nickel complexes in order to tailor the
molecular weights and branches of the resulting polyethylenes
Enhancing the Activity and Thermal Stability of Nickel Complex Precatalysts Using 1‑[2,6-Bis(bis(4-fluorophenyl)methyl)-4-methyl phenylimino]-2-aryliminoacenaphthylene Derivatives
The
series of acenaphthylene-1-[2,6-bisÂ(bisÂ(4-fluorophenyl)Âmethyl)-4-methylphenylimino]-2-arylimine
derivatives and their dichloronickel complexes were synthesized and
fully characterized as well as the single-crystal X-ray diffraction
of representative nickel complexes, revealing a distorted tetrahedral
geometry. Upon activation with either MAO or Et<sub>2</sub>AlCl, all
nickel complexes showed high activities in ethylene polymerization;
moreover, their catalytic systems showed better thermal stabilities
on being manipulated at 80 °C as the industrial operating temperature