fulltext.study @t Gmail

Synthesis and characterization of ether-imine-furfural [ONO] nickel(II) complexes and their application in oligomerization of ethylene

Paper ID Volume ID Publish Year Pages File Format Full-Text
38771 45790 2016 8 PDF Available
Title
Synthesis and characterization of ether-imine-furfural [ONO] nickel(II) complexes and their application in oligomerization of ethylene
Abstract

•New class of nickel catalysts bearing ether-imine-furfural ligands.•XPS data and DFT results indicate the formation of nickel dimeric species.•Nickel precatalysts exhibit high activities in ethylene oligomerization.•Activity and selectivity results are highly influenced by type of cocatalyst.

A series of new Ni(II) complexes of general formula {NiCl2(L)}2 [Ni1, L = 5-methyl-2-(C4H3O-2-CHN)C2H4OPh; Ni2, L = 5-Methyl-2-(C4H3O-2-CHN)Ph-2-OPh; Ni3, L = 2-(C4H3O-2-CHN)Ph-2-OPh; Ni4, L = 5-Methyl-2-(C4H3O-2-CHN)CH2Ph-2-OMe were prepared and characterized by IR spectroscopy, elemental analysis, high-resolution mass spectrometry (HRMS), and X-ray photoelectron spectroscopy (XPS). XPS data suggest no interaction of the pendant ether/furfural donor groups with the nickel metal center. Density functional theory studies indicate the formation of nickel dimeric species with ether-imine-furfural acting as a monodentate ligand. All nickel precatalysts, activated with polymethylaluminoxane-improved performance (PMAO-IP), exhibited moderate to good activities for ethylene oligomerization [TOF = 14.7–57.3 × 103 mol(ethylene) mol(Ni)−1 h−1] with high selectivities for production of 1-butene (63.2–83.2 wt.%). Activation of Ni2 using different types of cocatalysts (PMAO-IP, DMAO, MAO or EASC) led to formation of active oligomerization systems with a significant impact on the activity and selectivity. The use of MAO instead of PMAO-IP gave a slight improvement in the TOF [69.3 × 103 mol(ethylene) mol(Ni)−1 h−1] with lower selectivity for 1-butene. Higher activity was obtained using EASC as cocatalyst [206.1 × 103 mol(ethylene) mol(Ni)−1 h−1] along with a drastic reduction in the selectivity for 1-butene (10.4 wt.%). Under optimized conditions [[Ni] = 5 μmol, 30 °C, oligomerization time = 20 min, 20 bar ethylene, MAO as cocatalyst (500 equiv)], precatalyst Ni2 led to TOF = 63.2 × 103 mol(C2H4)·(mol(Ni)−1 h−1) and 75.2 wt.% selectivity for 1-butene.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (119 K)Download as PowerPoint slide

Keywords
Nickel catalysts; Ethylene oligomerization; 1-Butene; X-ray photoelectron spectroscopy; DFT calculations
First Page Preview
Synthesis and characterization of ether-imine-furfural [ONO] nickel(II) complexes and their application in oligomerization of ethylene
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 523, 5 August 2016, Pages 247–254
Authors
, , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us