CHMB41H3 Lecture Notes - Lecture 29: Alkene, Stereospecificity, Exothermic Process
Document Summary
Hydrogenation adding hs to the alkene. They are in to different phases not compatible with each together one is liquid one is gas. We need a catalyst to overcome the energy barrier because h bonds are strong bonds. Syn addition: they are either going to be both up or both down. Stereospecific if they start with syn they will get syn. Metals are in middle & they have d orbital. H2 gas dissociates into surface of metal ions - these are weak bonds. The pi electrons also get absorbed into surface of the metal. Now you have 2 particles of reaction in close proximity. Now h start to insert themselves into c-c pi bonds. Once c becomes tetravalent it dissociates away and then 2nd one follows. Now we have a fully saturated alkane. Since metals are expensive you want to reuse these as much as possible. Sometimes it doesn"t go to completion that"s why we still have double bonds.
