[Rosaniline]

Why paranitroaniline shows more basic properties than metanitroaniline?

[sjb]

Why paranitroaniline shows more basic properties than metanitroaniline?

How do you measure basicity?

[magician4]

@ sjb:

How do you measure basicity?

I fail to see how the mode of measuring basicity possibly could relate in any meaningfull way whatsoever to information  ref. what the structural origin of the difference in named basicity could possibly be, given that I had to compare p- and m- substituted systems.
... and would be eager to learn about your respective ideas

@ Rosaniline:
from a naive first analysis, basicity of amines is related to effective electron density in the lonepair electrons: the more the better, i.e. the more basicity the respective amine will show
one of the parameters influencing named basicity in aromatic amines could be described as "how much is this lonepair involved in mesomeric structures, and what do those structures mean with respect to "presence" of the lonepair as a lonepair at the nitrogen"

... and now you should try to think about how favourable mesomeric structures involving nitrogroup, aminogroup, aromatic system would possibly be related to the relative position amino ./. nitro


regards

Ingo

[sjb]

OK, perhaps "measure" is the wrong word to use. I was trying to get at the point that how basic something is can be considered, in this case, as how available the lone pair is to accept a proton. Then to go into the various mesomeric arguments you have set forth.

[Rosaniline]

Okay,I got it now.thank you all.