1. You understand that carbon with an unpaired electron is a radical, one of four major reactive intermediates in organic chemistry.
  2. You understand that radicals are formed by homolytic bond cleavage, and you can describe the difference between homolytic and heterolytic bond cleavage.
  3. You know the four classes of reaction that radicals undergo: atom abstraction, addition to multiple bonds, rearrangement, and recombination.
  4. You can rank the relative stability of tertiary, secondary, primary, and methyl radicals based on relative C-H BDEs, and can use these principles to estimate radical stability if given the respective C-H BDE.
    Visualization: Hyperconjugation in the tert-butyl radical
  5. You can draw each step for initiation and propagation in the conversion of methane and chlorine to chloromethane, and can draw at least one termination step in this mechanism.
    Visualization: Chlorination of Methane
  6. You can apply this mechanism to the radical halogenation of any C-H bond in any alkane.
  7. You can estimate ΔH° for each propagation step in an alkane halogenation and predict whether the overall conversion is feasible (exothermic) or not (endothermic).
  8. You can relate halogen reactivity to activation barriers for different halogenation reactions, and use that to qualitatively predict selectivity.
  9. You can use principles of symmetry and potential selectivity to state whether a particular halogenation is synthetically useful or not.
  10. You understand the role of resonance/Π delocalization in stabilizing allylic and benzylic radicals, weakening allylic and benzylic C-H bonds and promoting allylic and benzylic radical reactions such as bromination.
See a fun YouTube video illustrating C-H bind strength variation in photochemical bromination of alkylbenzenes.
Recommended problems: 3-15, 3-16, 3-19, 3-20, 3-21, 3-27, 3-30, 3-35, 3-40.

Worked problems:
Worked Problem 1
Worked Problem 2
Worked Problem 3