Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Organic Spectroscopy => Topic started by: a8nnie on June 11, 2013, 02:22:29 PM
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Hi guys!
Anybody who knows great organic chem programs for NMR-spectrums? Primarily H-NMR and C-NMR. I have an exam soon and I'd like to have a program which could generate a structure out of datas that you plot into the program.
Thank you so much! :)
/Annie
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You mean works out an NMR spectrum for a compound? Otherwise why not just use the graph function of Microsoft Excel, delta / 10^(-6) on the x-axis and relative abundance density on the y-axis (so that the integral is relative abundance). I'm not sure what the units on the y-axis should be, probably none. But you should be able to plot the ratios just by putting in the right values.
I'd also be interested to know if people have more efficient methods.
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No.. Actually vice versa. I need a program which can work/generate the structure out of NMR datas. I have like a sheet of datas that I have to interpret to get the structure and since that takes forever I'd really like a program which can do that for me
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Anybody who knows if chemsketch can do it? Like generate NMR data into a structure?
Please somebody.. I need help ;(
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I know programs that gives you the spectra of any structure you plug-in, for example, ChemDraw (Just the "Ultra" version, I think), so you can check if the structure you came with its correct... But I do not know of any program that does it backwards.
The only thing I think you could do is search your spectra into some NMR databases like this one: http://sdbs.riodb.aist.go.jp/sdbs/cgi-bin/cre_index.cgi
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Correct me if I'm wrong but there are professionals with postgraduate research and a lifetime of experience in the field of interpretation of NMR spectra ... it is not a simple computer's job.
Not only that, but several spectra will give a vast range of different possible compounds, particularly non-high res spectra. NMR is not the only organic identification tool used, for the reason that it sometimes leaves some ambiguity.
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Please somebody.. I need help ;(
A better strategy would be to study and learn how to interpret basic spectra on your own so you could be successful on the exam.
No such software is readily available to the average basic student.
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Anybody who knows if chemsketch can do it? Like generate NMR data into a structure?
Please somebody.. I need help ;(
Buy this book, this book is an awesome tool in interpreting spectra. once you complete the book you will be very capable of generating structures yourself. Its the best crash course available.
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Anybody who knows great organic chem programs for NMR-spectrums? Primarily H-NMR and C-NMR. I have an exam soon and I'd like to have a program which could generate a structure out of datas that you plot into the program.
I do not think creating a structure is terribly difficult if you have a good strategy for doing so. The method I use is like assembling Tinker Toys. If you had a compound with a MF C4H9Br, the spectrum may belie the simplicity of the solution. Even without a spectrum, if the integral was 3:2:2:2, you should be able to identify the compound. The NMR spectra identifies the carbons and hydrogens present. While an integral may tell you the presence of a CH2-group, the splitting and chemical shift can indicate additional connectivity. I find that putting these pieces together results in a logical path to a structure. In class I showed how the pieces can be identified from the spectra and how the pieces could be put together. In doing so, I generally found one can come to a relatively small number of choices. This brings me to another point. It is generally useful to draw the possible structures. It can then be easier to decide why one structure or a portion of the structure might be correct or incorrect. Returning to the C4H9Br example, there are only four possible structures. If you drew them, then you may realize you could identify each simply from the integrals.
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Thanks guys for all the replies!
Do you have any good advice concerning synthesis pathways as well as mechanism? I feel so lost when it comes to those two things. I dont even know how to start.. I know it sounds like I'm lazy and dont want to study but my exam is very soon and I just need it over with. Anybody who knows programs which can help me with mechanism and synthesis path ways?
/Annie