Question

1.1g of 9-fluorenol mixed with 11.1mL of hot methanol .11g of NaBH4 was then added. 3M of sulfuric acid was then added to the mixture, resulting in the formation of a solid. The mixture was then heated until the solid that formed upon the acid addition was dissolved in the solvent(methanol), and then cooled to room temperature.

9-fluorenol NMR: I've provided two sets of NMR's. The theoretical vs. the experimental. In the theoretical I understand all the shifts except for the 2.06, representative of the H alpha to the OH group. Methine protons usually have a shift around 1.7ppm and protons alpha to an (OH) are deshieled adding +2.5ppm, according to my textbook, which would make me think that the actual shift be 4.2ppm. Why is this not the case? Could I be mistaking this nuclei for another? I've attached my experimental NMR and I'm wondering what's causing alot of these seeemingly incorrect shifts. Is this due to impurities, and how would impurtities effect the NMR results. The huge integration 3.55ppm is 492. We used chlorofor as a solvent for NMR tubes so I was thinking maybe this caused the huge peak.

Thanks. IMAGES: http://imgur.com/a/gWTXM

Answer 1

First of all I want to tell you that the peak you got at 3.55 ppm in the expiremental data which may be due to of water.... Are your compounds crystalline.? Then it may be water of crystallisation.

your NMR is perfect and you are not missinf any other nuclei so I must need to say that it is because of the Humidity or due to the water.

The Purity of solvent does matter in NMR.

Reason: If you take a chloroform as a solvent and you have two impurities in your solvent such as Acetic acid and Acetone in your Solvent then, you will get two additional peak at 2.13 and 2.17 for the Acetic acid and Acetone.