I found a sentence given in my textbook:

More is steric effect more is acidic strength of carboxylic acids and more is steric effect less is basic strength of aniline and other amines.

Could someone please explain with an example?

I guess it might seem I am asking about ortho effect but I am not. I have gone through the post suggested but I am basically asking about subcases of ortho effect as in if we are asked to compare between ortho tertbutyl benzoic acid and ortho methyl benzoic acid then how would we go about it? Or suppose the questions asks comparing the basic strength between orthotert butyl amine and ortho methyl amine how would we do it ?

  • $\begingroup$ Please check out I have edited my post $\endgroup$
    – Charlie
    Jun 13, 2020 at 9:22
  • 1
    $\begingroup$ This kind of sentence is also mentioned in Finar, though not for carboxylic acids(as I have seen), reason was mentioned as steric acceleration as somehow the loss of H+ relieves the molecule of steric strain(I don't know the exact reason that's why I am commenting) and as amines are Lewis bases, steric retardation acts(groups are hindered during their approach). $\endgroup$
    – ba-13
    Jun 13, 2020 at 9:39
  • $\begingroup$ Please could you provide a complete answer . The reason I am not able to get properly $\endgroup$
    – Charlie
    Jun 13, 2020 at 15:19
  • $\begingroup$ Yes I looked up IL finar but the book doesn't really explain this matter. I am still confused $\endgroup$
    – Charlie
    Jun 13, 2020 at 20:17

1 Answer 1


Ortho tert butyl benzoic acid will be more acidic than the other one .because former is more bulkier so it will rotate the COOH group out of the benzene ring plane to a more extent .

For NH2 group Ortho to CH3 or C(CH3)3 .Ortho effect never applies NH2 can never go out of the plane .rather this time CH3 and C(CH3)3 goes out of plane .so hyperconjugation effect is lost only inductive effect is present .still tert one will be comparatively less basic because of STERIC INHIBITION OF PROTONATION (SIP) . Due to hindrance nitrogen can't donate it's electron pair easily to a proton


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