Nuclear Magnetic Resonance (NMR)
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Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful analytical technique used to determine the molecular structure and composition of organic compounds. Both proton (1H-NMR) and carbon-13 (13C-NMR) NMR spectroscopy provide valuable information about the nuclei in a molecule and their chemical environment.
1H-NMR spectroscopy primarily detects the signals emitted by hydrogen nuclei (protons) in a molecule when subjected to a strong magnetic field and radiofrequency radiation. The resulting spectrum reveals the chemical shifts of the protons, which are influenced by their neighboring atoms and functional groups. These chemical shifts provide insight into the electronic environment surrounding each proton, helping to identify the types of chemical bonds and molecular framework present in the compound. Additionally, the integration of the peaks in the 1H-NMR spectrum gives information about the relative number of protons contributing to each signal, aiding in the determination of the compound's structure and purity.
On the other hand, 13C-NMR spectroscopy detects signals from carbon-13 nuclei in a molecule. Unlike 1H-NMR, which typically provides more detailed information due to the higher natural abundance of hydrogen in organic compounds, 13C-NMR spectroscopy offers complementary data about the carbon atoms in a molecule. Carbon-13 nuclei have a lower natural abundance and are less sensitive to NMR detection compared to protons, so 13C-NMR spectra generally exhibit fewer peaks and lower signal intensity. Nevertheless, the chemical shifts observed in a 13C-NMR spectrum provide valuable information about the types of carbon atoms present (e.g., sp3, sp2, sp hybridized carbons) and their connectivity within the molecular framework.
Overall, both 1H-NMR and 13C-NMR spectroscopy are indispensable tools in organic chemistry for elucidating molecular structures, verifying chemical compositions, and studying the properties of organic compounds in solution.
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Baldovinos, Y., Obiako, P., Collom, C., & Sayes, C. M. (2024). A vape condensate collection method for degradant identification and toxicity screening. Journal of Hazardous Materials Letters, 5, 100099. https://doi.org/https://doi.org/10.1016/j.hazl.2023.100099