SN1 and SN2 reactions - mechanism and how to tell which will occur

An introduction into the difference between SN1 and SN2 substitution reactions. Elimination (E1 and E2) are not discussed. SN1 reactions involve the formation of a carbocation intermediate and SN2 reactions occur where the nucleophile displaces the leaving group at the same time. The biggest determining factor whether a substitution reaction proceeds via sn1 or sn2 is whether the carbon with the leaving group is primary, secondary or tertiary. Other influences include solvent, temperature and nucleophile strength. Polar aprotic solvents (DMSO....) will tend towards SN2 while polar protic tend towards SN1. The trends for nucleophilicity are explored briefly where stronger nucleophiles end up using SN2 more frequently and weaker nucleophiles will go the route of SN1. For more organic chemistry help including organic chemistry lectures, flashcards, problems, solutions and more go here: https://sites.google.com/site/thechem...