Haloalkanes and Haloarenes Cheat Sheet

Key Definitions

• Haloalkanes: Organic compounds containing carbon, hydrogen, and halogen (F, Cl, Br, I) atoms. ✅

• Haloarenes: Aromatic compounds where one or more hydrogen atoms are replaced by halogen atoms. ✅

Important Concepts

Structure and Reactivity

• Haloalkanes are generally more reactive than alkanes due to the polar C-X bond. ✅

• Haloarenes exhibit resonance stabilization, making them less reactive than haloalkanes. ✅

Nucleophilic Substitution Reactions

• Types:

• SN1: Unimolecular; involves a two-step mechanism. ✅

• SN2: Bimolecular; involves a one-step mechanism. ✅

• Factors:

• Substrate structure (primary, secondary, tertiary)

• Nucleophile strength

• Solvent type (polar protic vs. polar aprotic)

Key Formulas

Rate = k[substrate][nucleophile] (for SN2 reactions) ✅

• k: rate constant

• [substrate]: concentration of the haloalkane

• [nucleophile]: concentration of the nucleophile

Common Mistakes to Avoid

Common Mistake: Confusing SN1 and SN2 mechanisms, especially regarding the role of substrate structure.

Memory Tricks

Tip: "SN1 = 1 step; SN2 = 2 steps" — Remember the number of steps in the mechanisms.

Key Diagrams

Haloalkane Structure: 
      H   H
       \ /
        C - X
       / \
      H   H
Haloarene Structure:
        H
        |
   H - C - C - H
        |   \
        C - X
        |
        H