Living/controlled hex-1-ene polymerization initiated by nickel diimine complexes activated by non-MAO cocatalysts: Kinetic and UV–vis study

• Published in: Polymer (Guilford) 2011-01, Vol.52 (2), p.275-281
• Main Authors: Peleška, Jan, Hoštálek, Zdeněk, Hasalíková, Darja, Merna, Jan
• Format: Article
• Language: English
• Subjects: absorption; Activated; Applied sciences; Catalysis; Catalysts; catalytic activity; Dilatometry; Exact sciences and technology; Living/controlled olefin polymerization; molecular weight; Monomers; Nickel; Nickel catalyst; Non-MAO cocatalysts; Organic polymers; Physicochemistry of polymers; Polymerization; polymers; Preparation, kinetics, thermodynamics, mechanism and catalysts; Spectrometry; spectroscopy
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2010.11.029

Living/controlled polymerization of hex-1-ene initiated by nickel diimine catalysts of general form [ArN=C(1,8-naphthalenediyl)C=NAr]NiBr2 activated by simple organoaluminium compounds was investigated. Polyhexenes with a very narrow molar mass distribution and molar mass controlled by the monomer/initiator ratio were prepared using diethylaluminiumchloride, ethylaluminiumdichloride and methylaluminiumdichloride as cocatalysts for nickel complexes 1 (Ar = 2,6-iPr2C6H3) and 2 (Ar = 2-tBuC6H4). Nickel complexes with smaller aryl substituents (3, Ar = 2,6-Me2C6H3; 4 Ar = 2,4,6-Me3C6H2; 5, Ar = 2,6-Et2C6H3) undergo transfer reactions significantly. For the most bulky complex 1 activated by ethylaluminiumdichloride living hex-1-ene polymerization was achieved, proved by the reinitiation of polymer growth upon the addition of fresh monomer. The effect of Al/Ni ratio on the activity of the catalytic systems was studied by dilatometry. The catalytic systems were investigated by UV–vis spectrometry and a new interpretation of their absorption spectra was suggested. [Display omitted]