Bond Length Definition in Chemistry

What Is Bond Length?

Abstract molecules

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In chemistry, bond length is the equilibrium distance between the nuclei of two groups or atoms that are bonded to each other. Bond length is a property of a chemical bond between types of atoms. Bonds vary between atoms depending on the molecule that contains them. For example the carbon-hydrogen bond is different in methyl chloride as is methane. When more electrons participate in a bond, it tends to be shorter. Bond lengths in solids are measured using x-ray diffraction. In gases, length may be approximated using microwave spectroscopy.

Example Bond Lengths

Bond lengths are measured in picometers (pm). Example lengths for carbon include:

  • C-H single bond: 106-112 pm
  • C-C single bond: 120-154 pm
  • C-Te single bond: 205 pm

The trend follows that of atomic radius. Bond distances increasing moving down a group of the periodic table and decrease moving across a row or period.

Sources

  • Huntley D. R.; Markopoulos G.; Donovan P. M.; Scott L. T.; Hoffmann R. (2005). "Squeezing C–C Bonds." Angewandte Chemie International Edition. 44 (46): 7549–7553. doi:10.1002/anie.200502721