April 29, 2024, 06:06:04 PM
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Topic: NMR spec  (Read 3362 times)

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Offline krf24

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NMR spec
« on: March 28, 2014, 11:43:22 AM »
I am having some trouble identifying what this structure is according to the NMR data given. I'm not the best at understanding spectral graphs just yet. I have looked online and in my books trying to help me out on this problem, but I cannot figure this one out. There is a t on t peak at about .7 or 1.0 and I have never heard of a triplet on triplet being that close to the TMS peak. I do know some IR data which the major peaks given to me are 3000-2800 cm which could be alkyl C-H stretch or something else and strong at about 1740 cm which is a carbonyl group. Not given the actual IR graph to describe the peaks as well as the H-NMR and C-NMR. I have confirmed that the molecular formula is correct C8H16O2 with professor. The structure that seems to make the most sense to me is 2-methylbutyl propionate but I need help explaining how from the graphs, then again that could be wrong. The mass spec molecular ion is at 144 with the biggest peak at 57. (C8H16O2)

Offline DoctorDomo

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Re: NMR spec
« Reply #1 on: March 29, 2014, 05:29:04 PM »
Take a look at menthols spectrum:

Some serious peaks in between 0-1 there. I don't know what the cause of it is, but heres the page I spotted it on:
https://en.wikipedia.org/wiki/NMR_spectroscopy#Second-order_.28or_strong.29_coupling

Offline krf24

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Re: NMR spec
« Reply #2 on: March 31, 2014, 02:06:14 PM »
I don't think that is what I am exactly looking for. I had some tell me that the t on t is more of a multiplet and that it would be a big group like a butyl group on one side of the ester compound.

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