Haloalkanes

Naming Haloalkanes

• Haloalkanes - Chemical compound where one or more hydrogen atoms in alkane has been replaced by halogen

• Prefixes - Fluoro, Chloro, Bromo, Iodo

Polarity

• C-X bond is polar because halogen atoms are more electronegative than C. This causes and uneven distribution of electrons making C slightly positive and halogen is slightly negative

• This Polarity make the carbon a target for a nucleophile

Influence of C-X bond enthalpy on reaction rates

• Bond Enthalpy - Amount of energy required to break one mole of bonds between two atoms in the gaseous state.

• Bond enthalpy determines the reactivity of the haloalkanes

• Haloalkanes with lower C-X bond enthalpies have weaker bonds that need less energy to break

• C-X bond enthalpy decreases down Group 7 due to several factors because: Increasing atomic radius and increasing C-X bond length

• As a result, the energy needed to break these longer, weaker bonds decreases leading to faster reaction rates

• Iodoalkanes react fastest, Fluoroalkanes react slowest