NF_3 does not have donor properties like ammonia. Explain.
NF_3 has a pyramidal shape with one lone pair on N atom.
The lone pair on N is in opposite direction to the N–F bond moments and therefore, it has very low dipole moment (about 0.234 D). Thus, it does not show donor properties. But ammonia has high dipole moment because its lone pair is in the same direction as the N—H bond moments. Thus, it has donor properties.