Bond parameters are the measurable properties of a bond that, taken together, define the properties of the bonds in a molecule.
Examples of bond parameters are:
- Bond length
- Bond angle
- Bond strength
- Bond polarity
- Bond multiplicity
Bond length is the equilibrium distance between the nuclei of two bonded atoms.
For example, the length of an O-H bond in water is 95.7 pm. The length of an S-H bond in H₂S is 133.6 pm.
Bond angle is the average angle between the nucleus of the central atom and the nuclei of the bonded atoms.
For example, the H-O-H bond angle in water is 104 5 °,while the H-S-H bond angle in H₂S is 92.1 °.
Bond energy is the amount of energy required to break one mole of bonds of a particular type in a molecule in the gaseous state.
The bond strength of the O-H bonds in water is 459 kJ/mol. The bond strength of an S-H bond is 347 kJ/mol.
Bond polarity refers to the separation of charge in a bond. It results from electronegativity differences between the bonded atoms.
In water, the electronegativity difference is 1.24, so the O-H bond is polar covalent. In H₂S, the electronegativity difference is 0.38. Since this is less than 0.4, the S-H bond is nonpolar.
Bond multiplicity is the number of bonds between two atoms in a molecule.
Bond multiplicity determines the relative lengths of bonds. For example, bond lengths are in the order C-C > C=C > C≡C.