[xoggyux]

I have this question:
Why is more p-hydroxiacetophenone is more polar and have higher melting point than o-hydroacetophenone


I think i know the answer but I would like some confirmation and if possible more information
I believe is because the OH group (in p-hydroacetophenone) is further apart from the O=CH3 group (by the way how do you call this group ketone group? acetone group or what?) making it more stable by allowing the molecules to interact via hydrogen bonds.

[wanderlust]

In the ortho position the hydroxyl oxygen is able to interact intramolecularly (within itself) with the hydrogens attached to the terminal carbon on the carbonyl group.  This effectively reduces the intermolecular bonds between other molecules and decreases it's polarity and melting point. 

I hope this helps.  There may be more to it, or I might be wrong. 

[xoggyux]

actually that makes more sence that what I thought.
Wow I cannot believe my university, professors asking question they do not actually teach, I just found thanks to you what ortho is. Anyway thanks that helpead after a few googlings...

[wanderlust]

My pleasure!  Good luck.

[Squirmy]

If your professor hasn't talked about the effect of intramolecular hydrogen bonds on polarity (which wouldn't surprise me at all), it's probably not the answer they're after.

Have you learned anything about activating/deactivating groups in electrophilic aromatic substitution (EAS) reactions? Electron donating groups (EDG) vs. electron withdrawing groups (EWG)?

Granted, this isn't an EAS reaction, but the EDG and EWG concepts should still be useful.