Tuning ligand electronics and peripheral substitution on cobalt salen complexes: Structure and polymerisation activity

Linus Chiang, Laura E. N. Allan, Juan Alcantara, Michael C. P. Wang, Tim Storr, Michael P. Shaver

Research output: Contribution to journalArticlepeer-review

Abstract

A series of cobalt salen complexes, where salen represents an N2O2 bis-Schiff-base bis-phenolate framework, are prepared, characterised and investigated for reversible-termination organometallic mediated radical polymerisation (RT-OMRP). The salen ligands contain a cyclohexane diimine bridge and systematically altered para-substituted phenoxide moieties as a method to examine the electronic impact of the ligand on complex structure and reactivity. The complexes are characterised by single crystal X-ray diffraction, cyclic voltammetry, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy and computational methods. Structural studies all support a tailorable metal centre reactivity altered by the electron-donating ability of the salen ligand. RT-OMRP of styrene, methyl methacrylate and vinyl acetate is reported and suggests that cobalt–carbon bond strength varies with the ligand substitution. Competing β-hydrogen abstraction affords long-chain olefin-terminated polymer chains and well controlled vinyl acetate polymerisations, contrasting with the lower temperature associative exchange mechanism of degenerative transfer OMRP.

Original languageEnglish
Pages (from-to)4295-4304
JournalDalton Transactions
Volume43
Issue number11
Early online date9 Sep 2013
DOIs
Publication statusPublished - 21 Mar 2014

Fingerprint

Dive into the research topics of 'Tuning ligand electronics and peripheral substitution on cobalt salen complexes: Structure and polymerisation activity'. Together they form a unique fingerprint.

Cite this