[lalala123]

Please help....Important!!!

I came across a question while I was reading about the aldol reaction. I am not sure how to answer it. I have a test soon that can contain this question. The question is why H NMR is not a good enough way to characterize tetraphenylcyclopentadienone? Can anybody help?

[sjb]

Please help....Important!!!

I came across a question while I was reading about the aldol reaction. I am not sure how to answer it. I have a test soon that can contain this question. The question is why H NMR is not a good enough way to characterize tetraphenylcyclopentadienone? Can anybody help?

Without the full details, I'm not sure, but what would the proton NMR spectrum look like, do you think?

[darsinagoL]

Only based on what I remember.  Tetraphenylcyclopentadienone is based around a 5-carbon ring with 4 phenyl groups.  Benzene rings usually show up as a multiplet on an H NMR, so with 4 it may be a bit hard to distinguish the signal(s) (may get different signals, or a strong signal if there is symmetry.)  Also since the ring in the middle contains no Hydrogens the signal for the inner ring may also be difficult to distinguish, if it's there at all, since H NMR is based on the bonds Hydrogens have to their substituents.