The title nickel complex (C34H30Cl2N2NiO4, Mr = 660.21) has been synthesized and its crystal structure was determined by single-crystal X-ray structure analysis. It crystallizes in the monoclinic system, space group P21/n with a = 11.026(8), b = 11.491(8), c = 12.119(9) ?, β = 91.328(13)o, Z = 2, V = 1535.0(19) ?3, Dc = 1.428 g/cm3, F(000) = 684 and μ(MoKα) = 0.848 mm～1. The structure was refined to R = 0.0544 for 1813 observed reflections with I > 2σ(I) and wR = 0.0867 for 3132 unique reflections. The molecule of the complex is high symmetrical. Ni(II) atom is located in the symmetric center and coordinated to two phenolic oxygen and two imino nitrogen atoms, forming two six-membered rings. Upon activation with methylaluminoxane (MAO), it is active for ethylene oligomerization.
The title complex 1, C28H26CoN4O2, crystallizes in the triclinic system, space group P with a = 9.506(3), b = 9.506(3), c = 14.837(5) ? a = 106.397(5), b = 106.012(5), g = 91.889(6), V = 1217.7(7) 3, Z = 2, Dc =1.390 g/cm3, Mr = 509.46, F(000) = 530, m(MoKa) = 0.738 mm-1, the final R = 0.0359 and wR = 0.0951 for 4275 observed reflections with I > 2s(I). The complex adopts a distorted tetrahedral coordination sphere around the cobalt atom.
Aroylhydrazones,formed by condensation of benzoylhydrazine with benzoylaldehyde,2-methoxybenzoylaldehyde and 2,4-dimethoxybenzoylaldehyde,reacted with TiCl 4 to form their corresponding complexes.The titanium complexes were characterized by elementary analysis,IR,and 1H-NMR.Their catalytic properties for ethylene polymerization performed up to 104gPE/(molTi·h).The resultant PE was studied by DSC,GPC,WAXD,FT-IR analyses.The results reveal that the product obtained is a typical linear polyethylene.
A series of bridged ligand 4,4′-methylene-bis [2,6-dialkyl-N-(2-phenylmethylene)-anil] was efficiently synthesized by the condensation reaction of 4,4′-methylene-bis(2,6-disubstituted aniline) and salicyl aldehyde.They easily coordinated with Ni (Ⅱ) to form the title complexes,which were characterized by IR spectroscopy and elemental analysis.The complexes show good activities for vinyl polymerization of norbornene with methylalumoxane (MAO) as co-catalyst.The variations of complexes and catalytic parameters were investigated along with viscosimetric measurement of resultant polynorbornenes.
8-Aminoquinoline nickel dichloride and bis(cyclopentadienyl)zirconium dichloride (Cp2ZrC12) were supported simultaneously on silica to produce branched polyethylene successfully by combined polymerization. The supported polymerization results showed that the molecular weight of polyethylene increased while the molecular weight distribution became wider and the molecular chains of oligomers remaining in the final solution became shorter as compared to the oligomers obtained in polymerization processes with pure 8-aminoquinoline nickel dichloride catalysis, as well as the Cp2ZrC12 and nickel combination system. With decreasing amount of Ni catalyst in the supported catalyst, the molecular chains of oligomers in the resulting solution became shorter, while a-olefin selectivity increased.
