CHEM 112A Lecture Notes - Lecture 12: Stereochemistry, Molecularity, Leaving Group
Document Summary
Associative (won"t discuss much in this course) Unimolecular= rxn takes place one molecule at a time (first order); can have multiple steps. Nucleophile attacks, takes place of leaving group. Example rxn: solvent (ch3)3cbr (ch3)3c+ + br (sn1) nucleophile attacks (nuc. ) (ch3)3. The rate of the reaction is dependent on the concentration of the molecule (alkyl chain) that formed the intermediate. *so in this case, the rate of the above rxn is dependent on this molecule* Also, the above rxn involved solvolysis which is when the solvent also acts as the nucleophile/base in solution: interchange (sn2) Bimolecular= involves two molecules reacting at the same time. The approaching group (nucleophile) displaces the leaving group. As the nucleophile approaches, the leaving group leaves; done at same time. C lg ignoring the hydrogens for now, the nucleophile is approaching from the back, called a backside displacement. The nucleophile is attaching as the leaving group displaces; one step. nuc.
