[redfox]

I did an experiment with phenol, 3-nitrophenol and 3-chlorophenol where I mixed them in water and octanol and found out the partition coefficients for each of them (P1, P2 and P3 respectively).
I then took the log of each, and figured out the π value (log p2 - log p1, log p3 - log p1).
The 3-nitrophenol had a higher value than phenol, and 3-chlorophenol had a higher value still. Can anyone please explain to me why adding the different substituents changes the value? I can't seem to piece the info together to make sense.
The Hammett constant of Cl at the meta position is 0.37 and NO₂ at the meta position is 0.73 which doesn't seem to fit, because the chlorophenol had a higher π value than NO2 but here the NO₂ is more electron withdrawing.

Thanks in advance for any advice:)

[Rabn]

How do the resonant structures of 3-nitrophenol effect the stability of the molecule and its solubility?