Answer to Question #77979 in Organic Chemistry for chinny

Question

Factors affecting bond length of a compound

Answer 1

Bond length is the equilibrium state between the centers of the atoms (r).

1. With the increase in the serial number of the element, its covalent radius increases, and the lengths of the corresponding bonds increase:
C-F (0.138 nm) < C-Cl (0.178 nm) < C-Br (0.194 nm) < C-I (0.214 nm)

2. The change in the hybrid orbitals of an atom leads to a change in its covalent radius and the length of its bonds with other atoms:
CH3 - CH3 (Csp3 - Csp3) 0.154 nm
CH2 = CH2 (Csp2 = Csp2) 0.134 nm
HC ≡ HC (Csp ≡ Csp) 0.120 nm

With the increase of the s-orbitals into hybrid orbitals the bond length decreases