ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis, characterization, and ethylene oligomerization of three novel dendritic nickel catalysts

Jun Wang, Li-Li Ma, Lei Song, Si-Han Wang, Hong-Liang Huo, and Cui-Qin Li

Key Laboratory of Oil Gas and Chemical Technology, College of Chemistry and Chemical Engineering, Northeast Petroleum University, Daqing, China

E-mail: dqpilicuiqin@126.com

Abstract: Three dendritic nickel complexes C1–C3 were synthesized from three poly(amido amine) dendrimers, salicylic aldehyde and nickel chloride hexahydrate via Schiff base condensation reaction and coordination reaction. The structures of the dendritic ligands and nickel complexes were characterized by FT-IR, UV, ¹H NMR, ESI–MS, and elemental analysis. When activated with aluminum co-catalysts, three complexes C1–C3 were able to catalyze ethylene oligomerization. The catalytic activities and the product distribution of complexes C1–C3 were depended on the reaction parameter, co-catalyst, solvent, and the structure of the pre-catalyst. When using ethyl aluminum sesquichloride (EASC) as co-catalyst in toluene, the catalytic activity of complex C3 containing the longest bridging methylene groups reached the highest value of 1.63 × 10⁶ g·(mol Ni·h)⁻¹ with 69.15% C₁₁ in the product at 30 min, 25 °C, 0.5 MPa, and Al/Ni ratio of 900.

Keywords: Dendritic nickel complex; Ethylene oligomerization; Bridging group; Co-catalyst

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-016-0009-3

Chemical Papers 71 (5) 895–904 (2017)