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Chemistry Forums for Students => Organic Chemistry Forum => Organic Spectroscopy => Topic started by: CrimpJiggler on December 03, 2011, 11:31:11 PM

Title: pKa and HNMR chemical shifts
Post by: CrimpJiggler on December 03, 2011, 11:31:11 PM
I notice that carboxylic -OH protons appear way low field on the HNMR spectrum which makes sense because they are so deshielded. Isn't an acids Ka directly proportional to the extent to which its proton is deshielded though? In other words, wouldn't the location of a carboxyl groups HNMR peak depend on its pKa? The acidic proton of trifluoroacetic acid is obviously way more deshielded than that of butanoic acid so wouldn't its peak appear much further down field?