Effect of ligand backbone substituents of nickel α‐diimine complexes on livingness/controllability of olefin polymerization: Competition between monomer isomerization and propagation. Issue 19 (2nd July 2016)

• Record Type: Journal Article
• Authors: Sokolohorskyj, Anatolij; Mundil, Robert; Lederer, Albena; Merna, Jan
• Is Part Of: Journal of polymer science. Volume 54:Issue 19(2016)
• Page Start: 3193
• Page End: 3202
• Publication Date: 2016-07-02
• Subjects: isomerization -- kinetics -- living/controlled polymerization -- nickel -- olefin; 547
• DOI: 10.1002/pola.28206
• Languages: English
• ISSNs: 0887-624X

Abstract

ABSTRACT: Four α‐diimine nickel complexes [(ArNC(R) C(R)NAr)NiBr2 ; RH, CH3, cyclohexane‐1, 2‐diyl, naphthalene‐1, 8‐diyl, Ar2, 6‐ i ‐Pr2 ‐C6 H3 ‐) were investigated in propene and hex‐1‐ene polymerization to identify the limits of backbone substituent R size needed to provide living/controlled α‐olefins polymerization by the sufficient suppression of β – H elimination transfer. Propagation kinetics measurements, molar mass on monomer conversion dependencies and reinitiation tests were used to evaluate the livingness of hex‐1‐ene polymerization. Interestingly, living/controlled hex‐1‐ene polymerization was observed in the case of all diimine derivatives including the one bearing only hydrogen atom in backbone positions. Unexpectedly, in the case of catalysts bearing H and CH3 backbone substituents, we observed the unusual isomerization of hex‐1‐ene into internal hexenes in parallel with its polymerization. Nevertheless, by subtracting the amount of monomer consumed in isomerization side reaction, polymerization still keeps the features of living/controlled process. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2016, 54, 3193–3202 Abstract : The size of ligand substituents of α‐diimine nickel complexes is investigated to find limits for living/controlled polymerization of olefins. Living/controlled hex‐1‐ene polymerization is possible with all diimine derivatives including the one bearing only a hydrogen atom in backbone positions. Catalysts with H and CH3 backbone substituents isomerize hex‐1‐ene into internal hexenes. Nevertheless, by subtracting the amount of monomer consumed in the isomerization reaction, polymerization still keeps the features of living/controlled process.