Question

How would you label the H NMR and IR spectra of hydroxyfluorene? Sorry I cannot post pictures, otherwise I would upload the spectra. I am doing a characterization for a lab and think I have some odd peak labels. Thanks!

Answer 1

Answer – We are given the hydroxyfluorene and need to the label the H NMR and IR spectra. We can draw the structure and write the proton chemical shift for each –

In the hydroxyfluorene the plane of symmetry , so total number of proton sets are 6 and out of these 6 peak there is one for -OH and another for -CH at cyclopentane ring. There are 4 peak for the benzene ring.

IR data – There is -OH as IR frequency between the 3200-3600 and peak is board due to H-bonding.

There is Ar C=C, so peak between 1500-1600 cm^-1.

¹HNMR-

At 2.0 ppm singlet for 1 H the 1 H - OH

At 5.60 ppm singlet for 1 H the 1 H

At 7.5 ppm doublet of doublet for 2H , Ar-H

At 7.3 ppm triplet and doublet for 2H , Ar-H

At 7.4 ppm triplet and doublet for 2H , Ar-H

At 7.8 ppm doublet of doublet for 2H , Ar-H

Structure of hydroxyfluorene -