Explain the electronic structure of amine compounds with a diagram.

(N/A) Like ammonia,the nitrogen atom of amines is trivalent and carries an unshared pair of electrons. Nitrogen orbitals in amines are therefore $sp^{3}$ hybridised,and the geometry of amines is pyramidal.
Each of the three $sp^{3}$ hybridised orbitals of nitrogen overlaps with the orbitals of hydrogen or carbon,depending upon the composition of the amines.
The fourth orbital of nitrogen in all amines contains an unshared pair of electrons. Due to the presence of this unshared pair of electrons,the bond angle $C-N-E$ (where $E$ is $C$ or $H$) is less than $109.5^{\circ}$; for instance,it is $108^{\circ}$ in the case of trimethylamine.