Organic Chem - Alkyl Halides

Organic Halogen Compounds

Compounds that contain one or more halogens (X = halogen) combined with carbon and other elements.

Alkyl Halides (RX)

A subset of organic halogen compounds that contain an alkyl group bound to a halogen atom (X = F, Cl, Br, or I) via a sp3 carbon atom.

How are organic halogen compounds made?

They are made by the addition of HCl or HBr to alkenes and acetylenes (hydrohalogenation) or the addition of Cl2 or Br2 to alkenes and acetylenes (halogenation).

Why are alkyl halides useful?

They are reactive compounds due to the nature of the C-X bond, excellent electrophiles, and form stable leaving groups as halide anions.

Nucleophile

A species that is nucleus-seeking, electron-rich, and willing to give away electrons (e.g., HO-, :NH3, H3C-, C=C).

SN Reaction

Nucleophilic substitution reaction where a nucleophile replaces the halogen (X) in an alkyl halide (RX).

Reactivity of Alkyl Halides

Reactivity depends on R-X bond strength; reactions become faster from R-Cl to R-Br to R-I due to weakening bond strength.

Negative Ions as Nucleophiles

Negative ions are better nucleophiles than their corresponding neutral molecules.

what makes reactions faster?

weakening bond strength

what makes reactions slower?

increasing bond strength