Polymer processing steric inhibition

Since their discovery over a decade ago, late transition metal a-diimine polymerization catalysts have offered new opportunities in the development of novel materials. The Ni(II) catalysts are highly active and attractive for industrial polyolefin production, while the Pd(II) catalysts exhibit unparalleled functional group tolerance and a propensity to form unusually branched polymers from simple monomers. Much of the success of these catalysts derives from the properties of the a-diimine ligands, whose steric bulk is necessary to accelerate the insertion process and inhibit chain transfer. 

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