Question

Compare the dipole moment of the following: O nitrophenol O dichlorobenzene O xylene

According to me, o dichlorobenzene should have the highest dipole moment since the angle will be acute but in o nitrophenol it will be obtuse. And o xylene should have the least since the dipole strength would be lesser as compared to others but surprisingly the order is: O nitrophenol(3.01D)>o dichlorobenzene(2.67D)> o xylene(0.64D) How?(data collected from internet)

Answer 1

Answer on Question #79524 – Chemistry – Inorganic Chemistry

Compare the dipole moment of the following: O nitrophenol O dichlorobenzene O xylene

According to me, o dichlorobenzene should have the highest dipole moment since the angle will be acute but in o nitrophenol it will be obtuse. And o xylene should have the least since the dipole strength would be lesser as compared to others but surprisingly the order is: O nitrophenol (3.01D) > o dichlorobenzene (2.67D) > o xylene (0.64D) How?(data collected from internet)

Solution:

Because dipole is pointed from less electronegative atom to more electronegative. So due to $\mathrm{NO}_2$'s -R effect it will be from carbon to nitrogen, but due to +R effect of phenol it will be from oxygen to carbon.