Help with interpreting NMR and IR spectrums

  • Thread starter GoGoGadget
  • Start date
  • Tags
    Ir Nmr
It is also possible that the shift in carbonyl peak is due to resonance effects in the hydrogenated product. Overall, it seems like you have a good understanding of how to interpret NMR and IR spectra for this type of experiment. Keep up the good work!In summary, the conversation discusses interpreting NMR and IR spectra for a synthesized product of Chalcone. The student is seeking confirmation on their peak determinations and notes a shift in the carbonyl peak from the Chalcone IR spectrum to the hydrogenated spectrum. It is suggested to consult with an instructor or professor and compare to known compounds for further confirmation. It is also mentioned that the shift could be due to resonance effects.
  • #1
GoGoGadget
31
0

Homework Statement



Would anyone be able to tell me if I'm on the right track with determining the peaks on these NMR spectrums? We had to synthesize a product of Chalcone and then hydrogenate it to obtain an unknown product that we have to correctly identify. This had been quite a difficult spectrum for me to interpret and any input would be appreciated! For the IR spectrums, I think I have the right peaks determined and noticed that the carbonyl shift was at 1660 cm-1 on the Chalcone IR and then switched to a higher energy level in the hydrogenated spectrum at 1675 cm-1 from the chalcone spectrum. Is this due to resonance?



Homework Equations



N/A

The Attempt at a Solution




Listed on spectrum.
 

Attachments

  • NMR of Chalcone 1.jpg
    NMR of Chalcone 1.jpg
    24.4 KB · Views: 2,184
  • NMR of Hydrogenated Product.jpg
    NMR of Hydrogenated Product.jpg
    29 KB · Views: 867
Physics news on Phys.org
  • #2
You may want to consult with your instructor or a professor to double check your results. Generally speaking, the peaks on an NMR spectrum should correspond to the expected chemical shifts for the atoms in the molecule. For example, a carbonyl peak should be around 1660 cm-1 and an aromatic peak should be around 7-8 ppm, etc. Additionally, you can compare the spectrums to known compounds to help narrow down possible structures.
 

FAQ: Help with interpreting NMR and IR spectrums

1. How do I interpret the peaks in an NMR spectrum?

To interpret peaks in an NMR spectrum, you need to consider the chemical shifts, integration values, and multiplicity of the peaks. Chemical shifts indicate the environment of the hydrogen atoms, integration values show the relative number of protons in each environment, and multiplicity informs about the number of neighboring protons. By analyzing these factors, you can determine the structure of the molecule.

2. What is the difference between a 1H and 13C NMR spectrum?

The main difference between a 1H NMR and 13C NMR spectrum is the type of nuclei being analyzed. 1H NMR measures the absorption of hydrogen atoms, while 13C NMR measures the absorption of carbon atoms. Additionally, 13C NMR spectra tend to have fewer peaks and show less splitting due to the lower natural abundance of 13C compared to 1H.

3. How do I identify functional groups in an IR spectrum?

To identify functional groups in an IR spectrum, you need to analyze the peaks and their corresponding wavenumbers. Each functional group has characteristic peaks at specific wavenumbers, allowing for their identification. For example, a C=O bond typically shows a strong peak around 1700 cm-1, while an OH bond appears around 3300 cm-1.

4. Can IR and NMR spectra be used to determine the exact structure of a compound?

IR and NMR spectra are helpful tools for determining the structure of a compound, but they cannot provide the exact structure on their own. Other techniques such as mass spectrometry and elemental analysis may be needed to confirm the structure. Additionally, the interpretation of spectra requires knowledge and experience, so consulting with a specialist may also be necessary.

5. How do impurities affect NMR and IR spectra?

Impurities can significantly affect NMR and IR spectra, making it difficult to accurately interpret them. In NMR, impurities can cause additional peaks, overlap of peaks, or shifts in the chemical shifts. In IR, impurities can appear as additional peaks, making it challenging to identify functional groups. To obtain reliable spectra, it is essential to purify the sample before analysis.

Similar threads

Expert Help with Mass Spectroscopy Homework: IR & NMR Analysis for Molecule B
Replies
2
Views
3K
Interpreting NiCl2 (dppe) H-NMR Peaks: Chemical Shift Analysis
Replies
1
Views
2K
NMR NOESY spectrum - Please help trans-9-(2-phenylethenyl) anthracene
Replies
2
Views
14K
Accurately and Quickly Interpreting NMR/IR Spectra
Replies
5
Views
9K
What are the key steps to analyzing an NMR spectrum?
Replies
1
Views
4K
Chemistry H NMR Spectrum - Molecular Structure
Replies
2
Views
12K
H NMR of unknown sample (organic chem)
Replies
4
Views
3K
How Do You Interpret Spectral Data for This Compound?
Replies
3
Views
4K
Help me identify peaks in H NMR please
Replies
2
Views
20K
Organic Chemistry - 1H and 13C NMR Problem. HELP
Replies
1
Views
3K

Hot Threads

Recent Insights

Back
Top