1H-NMR for conformation elucidation

  • Thread starter amattiol
  • Start date
In summary, the individual is having difficulty determining the conformer and assigning H-NMR peaks for a compound with a N,N-diisopropylacetamidine and is seeking help. They have assigned most of the peaks, but are unsure about the E conformation based on the NMR data. They suspect both E and Z conformations may exist in solution.
  • #1
amattiol
8
0
Hello,
I have having some difficulty determining the conformer and assigning H-NMR peaks for a compound with a N,N-diisopropylacetamidine (R-NH-C(CH3)N(2[CH[2(CH3)]])... essentially a diisopropylamine added to CH3CN (ACN). my H-NMR spectrum (at room temp) in CD3CN consists of:
I have assigned all but the singlets

B singlet at 5.8ppm R-NH
B septet at 4.00 CH connected to the N of the diisopropylamine
singlet 2.37
singlet 2.15

TMS at 1.98
doublet at 1.26ppm methyls from the isopropyl
Very B singlet -4.9 μ-BHB

The E conformation is suspected based on theory and steric repulsions, but i cannot justify it from any of the NMR data I have (1H, variable temp 13C, or 11B)

my best guess in regards to those singles is that both E and unfavorable Z conformations exist in solution.

Any help would be greatly appreciated.
 
Chemistry news on Phys.org
  • #2
I'm sorry you are not generating any responses at the moment. Is there any additional information you can share with us? Any new findings?
 

1. What is 1H-NMR for conformation elucidation?

1H-NMR (proton nuclear magnetic resonance) is a technique used in chemistry to study the structure and conformation of molecules. It measures the different energy levels of hydrogen nuclei in a molecule, providing information about the relative positions of atoms and their connectivity.

2. How does 1H-NMR help in determining molecular conformation?

By analyzing the chemical shifts and coupling patterns of hydrogen nuclei in a molecule, 1H-NMR can provide information about the orientation and arrangement of atoms in a molecule. This can help in determining the molecular conformation, or the spatial arrangement of atoms in a molecule.

3. What are the advantages of using 1H-NMR for conformation elucidation?

1H-NMR is non-destructive, meaning the sample is not altered during the analysis. It is also a highly sensitive technique, capable of detecting small changes in molecular conformation. Additionally, it is a relatively fast and accurate method for determining molecular conformation.

4. Are there any limitations to using 1H-NMR for conformation elucidation?

One limitation of 1H-NMR is that it is not always able to provide a complete picture of molecular conformation. This is because it only provides information about the arrangement of hydrogen atoms, and other elements in the molecule may affect the signals. Additionally, it is not suitable for studying large molecules or those with highly complex structures.

5. How is 1H-NMR for conformation elucidation used in research?

1H-NMR is commonly used in research to study the conformation of small molecules, such as organic compounds. It can also be used to study the effects of environmental factors, such as temperature and solvent, on molecular conformation. Additionally, 1H-NMR can aid in the development of new drugs by providing insight into the structure of potential drug molecules and how they interact with biological targets.

Back
Top