[jmgx12]

Hi. I just did a Cannazzaro reaction in lab where we took 4-chlorobenzaldehyde and made 4-chlorobenzoic acid and 4-chlorobenzyl alcohol. However, I am looking at my carbon NMR for 4-chlorobenzyl alcohol and looking at references online. Here is the carbon NMR for the molecule:
http://www.chemicalbook.com/SpectrumEN_873-76-7_13CNMR.htm

Now my question is...why in the world does the carbon in the aromatic ring attached to the CH2OH (carbon labeled 1 in picture) appear further downfield than the carbon attached to the chlorine (labeled 2 in picture)? Doesn't make much sense to me. I would think since it is DIRECTLY attached to an e-withdrawing group, it would be deshielded more than something that has a CH2 in between that and an e-withdrawing oxygen. Thanks.

[meshohel]

This 13C NMR seems like generated by software. Real spectrum is different. Here is the FTNMR from sigma aldrich website. Quarternary carbons are not that easy to see. Do you have your own spectra?

[PhDoc]

Very strange NMR you have there. Sorry, thought you were asking something else.

[orgopete]

This 13C NMR seems like generated by software. Real spectrum is different. Here is the FTNMR from sigma aldrich website. Quarternary carbons are not that easy to see. Do you have your own spectra?

The NMR looks fine. That fact that they weighed out the sample suggests it was recorded. However, the spectrum referred to by meshohel is a ¹H-NMR.

I'll leave it to someone else to explain the chemical shifts. I'm more of a look them up and discover where they might be.

[camptzak]

I think, to answer your original question, That the carbon attached to the Chlorine can draw electrons from the lone pairs around the Chlorine. The Chlorine is tertrahedral and the aromatic ring is pulling electrons into the pi system, so the lone pairs around the electronegative chlorine are actually pulled in towards that carbon making it less exposed to a magnetic field.

The carbon in the aromatic ring is atached to the CH₂OH. This carbon is attached to another carbon and does not have the benefit of octet resonance stabilization. So it is less shielded than the carbon attached directly to a chlorine.

Does that make sense?