Introduction to Haloalkanes and Haloarenes

Haloalkanes and Haloarenes

• Haloalkanes and haloarenes are a class of organic compounds that contain halogen atoms.

Nomenclature and Structure

• Haloalkanes are named by replacing the suffix "-ane" in the parent alkane with "-halo" (e.g., chloromethane).
• Haloarenes are named by adding the prefix "halo-" to the parent arene (e.g., chlorobenzene).

Methods of Preparation

• Halogenation of alkanes: reaction of alkanes with halogens (Cl2, Br2, I2) to form haloalkanes.
• Free radical halogenation: reaction of alkanes with halogens in the presence of UV light.
• Halogenation of alkenes: reaction of alkenes with halogens to form haloalkanes.

Physical Properties

• Boiling points: increase with increasing molecular weight and decreasing polarity.
• Melting points: increase with increasing molecular weight and symmetry.
• Solubility: haloalkanes are generally insoluble in water but soluble in organic solvents.
• Density: typically higher than that of water.

Chemical Reactions of Haloalkanes

• Nucleophilic substitution: reaction with nucleophiles (e.g., OH-, CN-) to form substituted compounds.
• Elimination reactions: reaction with strong bases to form alkenes.
• Reaction with metals: reaction with metals (e.g., Na, Zn) to form organometallic compounds.

Chemical Reactions of Haloarenes

• Electrophilic aromatic substitution: reaction with electrophiles (e.g., NO2+, Cl+) to form substituted arenes.
• Nucleophilic aromatic substitution: reaction with nucleophiles (e.g., OH-, CN-) to form substituted arenes.
• Sandmeyer reactions: reaction with copper(I) salts and amines to form diazonium salts.

Uses of Haloalkanes and Haloarenes

• Intermediates in organic synthesis.
• Pharmaceuticals: used as anesthetics and in the production of pharmaceuticals.
• Pesticides: used as insecticides and herbicides.
• Solvents: used as solvents in various industrial applications.