Adiponitrile (1,4-dicyanobutane) can be synthesized from butadiene and HCN using a homogeneous nickel catalyst. Adiponitrile is a precursor for Nylon-6,6.

a) Propose a mechanistic cycle for the formation of the first hydrocyanation product from butadiene with the precursor catalyst [Ni(PP)2] (PP = bidentate phosphite ligand). Which two products will be formed?

b) Discuss in detail the different binding modes and fluxionality of a propenyl  (also known as allyl) group at a metal center.

c) Discuss which additional steps are necessary to form the desired adiponitrile product from the initial products formed after the first reaction.

d) Which two factors (Tolman) are used to describe the properties of a phosphorus ligand? How can these factors be quantified? Explain why for the hydrocyanation catalyst the use of phosphite ligands is essential.

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a The DuPont process which forms the basis of an industrialprocess for the manufacture of adiponitrile ADN is an early successful example of homogeneo... View the full answer