A C-N bond is considered to be a polar covalent bond. This is due to the difference in electronegativity between carbon (C) and nitrogen (N).
Electronegativity is the tendency of an atom to attract electrons towards itself when forming a bond. Carbon has an electronegativity of about 2.5, while nitrogen has a higher electronegativity of approximately 3.0. The difference in their electronegativities indicates that nitrogen has a stronger pull on the bonding electrons compared to carbon.
As a result, in a C-N bond, the electrons are not shared equally. The nitrogen atom attracts the shared electrons closer to itself, creating a dipole moment where the nitrogen end is slightly negative (δ-) and the carbon end is slightly positive (δ+). This uneven distribution of charge leads to the bond being classified as polar covalent.
In summary, the C-N bond is polar covalent due to the difference in electronegativity between carbon and nitrogen, resulting in an unequal sharing of electrons.