- 4 Hydrocyanation Involves The Addition Of Hcn To An Alkene To Form A New C C Bond And Introduce New Functionality Into 1 (40.69 KiB) Viewed 8 times
- 4 Hydrocyanation Involves The Addition Of Hcn To An Alkene To Form A New C C Bond And Introduce New Functionality Into 2 (69.4 KiB) Viewed 8 times
4. Hydrocyanation involves the addition of HCN to an alkene to form a new C-C bond and introduce new functionality into the compound. A proposed mechanism for the hydrocyanation of ethene to form propionitrile is shown below. 1 Et-CN R₃P HCN R; p=Ni- E A T 2 R₂P Ni-H 5 RPM Et Ni-PR3 R₃pm CN CN B D PR3 PRE R₃P! RP. Ni-H Ni Et CN 4 с CN 3
b. Provide the number of valence electrons, coordination number, oxidation state and dn-configuration for complexes 1-5. Hint: assume CN is an X- type ligand [5 marks] c. Name steps A-E. [5 marks] d. Consider complex 1. i. Draw a molecular orbital (MO) energy level diagram to describe the interactions between the nickel and the alkene ligand. You must include sketches of the orbital overlaps for full marks. [4 marks] ii. Suggest a strategy to increase the strength of the interaction between the metal and alkene ligand. Briefly explain how and why this strategy affects metal-carbon and carbon-carbon bond strength and geometry. (4 marks]