# Why is the carbon-fluorine bond stronger than the other haloalkanes? [closed]

What effect makes C-F bond stronger than other halo-alkanes?

The high electronegativity of fluorine (4.0 for F vs. 2.5 for carbon) gives the carbon–fluorine bond a significant polarity/dipole moment. The electron density is concentrated around the fluorine, leaving the carbon relatively electron poor. This introduces ionic character to the bond through partial charges ($\ce{C^{δ+}—F^{δ−}}$). The partial charges on the fluorine and carbon are attractive, contributing to the unusual bond strength of the carbon–fluorine bond. The bond is labeled as "the strongest in organic chemistry," because fluorine forms the strongest single bond to carbon. Carbon–fluorine bonds can have a bond dissociation energy (BDE) of up to 544 kJ/mol. (This is why) The BDE (strength of the bond) is higher than other carbon–halogen and carbon–hydrogen bonds. For example, the molecule represented by $\ce{CH3X}$ has a BDE of 115 kcal/mol for carbon–fluorine while values of 104.9, 83.7, 72.1, and 57.6 kcal/mol represent $\ce{C–X}$ bonds to hydrogen, chlorine, bromine, and iodine, respectively.