NMR Spectroscopy: A Powerful Tool for Probing Molecular Structure, Dynamics, and Interactions

Using the magnetic properties of some nuclei to study molecular structures, dynamics, and interactions is a strong analytical method known as nuclear magnetic resonance (NMR) spectroscopy. Researchers can watch how nuclei behave, especially hydrogen (¹H) and carbon (¹³C), which are common in organic molecules, by using a strong magnetic field. This method gives information about the make-up and interactions of molecules at the atomic level. It is very useful in many areas, such as chemistry, biology, and materials science.

The basic idea behind NMR is that nuclear spins will resonate when they are in a magnetic field. The chemical surroundings of these nuclei can change how they react, which lets us get a good picture of their structures. One example is Nakazawa et al. (2012), who used solid-state NMR to look into silk-polyurethane compounds and found interactions and dynamics that change molecular motion and cross-relaxation rates between ¹H and ¹³C nuclei. Kharkov et al. (2014) also used ¹H− ¹³C dipolar NMR spectroscopy to look at phase changes and molecular dynamics in surfactants mixed in with clay minerals. This allowed them to directly measure the order parameter patterns in layered composites.

NMR can also be used to look at molecular dynamics in addition to static structural studies. Hansen et al. (2013) talked about how NMR is one of the only tools that can look at both the structure and motion of large molecules at the same time. They stressed how important it is for understanding how complex polymers behave. The results from Ghitti et al., who studied ligand-receptor interactions using NMR and computer methods, back this up even more. They showed that NMR can help us understand how molecules change over time (Ghitti et al., 2013). For example, Wojnarowska et al. showed that understanding molecular dynamics in amorphous pharmaceuticals can have a big effect on their macroscopic properties (Wojnarowska et al., 2013). This shows how important NMR is for studying molecular mobility in drug design and materials science.

NMR can do more than just describe structures and dynamics; it can also show how things in complex mixes interact with each other. To give you an example, Vinogradova and Qin (2011) talked about how NMR is great at tracking weak protein-protein interactions that are hard to study with other methods. This skill is necessary to understand how biological processes work and come up with new medicines. NMR is also useful for studying the environment because it can be used to look at complicated samples like soil and plant cells and show how their components change and interact (Simpson et al., 2012).

Researchers who want to understand the structures and movements of molecules can’t do their work without NMR spectroscopy. It is an important tool in many science fields because it can give us detailed information about how molecules interact and behave at the atomic level. Molecular characterization tools like NMR are always getting better because new methods are being developed that make it more useful.

References

Ghitti, M., Musco, G., & Spitaleri, A. (2013). Nmr and computational methods in the structural and dynamic characterization of ligand-receptor interactions., 271-304. https://doi.org/10.1007/978-3-319-02970-2_12

Hansen, M., Graf, R., & Spiess, H. (2013). Solid-state nmr in macromolecular systems: insights on how molecular entities move. Accounts of Chemical Research, 46(9), 1996-2007. https://doi.org/10.1021/ar300338b

Kharkov, B., Corkery, R., & Dvinskikh, S. (2014). Phase transitions and chain dynamics of surfactants intercalated into the galleries of naturally occurring clay mineral magadiite. Langmuir, 30(26), 7859-7866. https://doi.org/10.1021/la501898x

Nakazawa, Y., Asano, A., Nakazawa, C., Tsukatani, T., & Asakura, T. (2012). Structural characterization of silk-polyurethane composite material for biomaterials using solid-state nmr. Polymer Journal, 44(8), 802-807. https://doi.org/10.1038/pj.2012.119

Simpson, A., Simpson, M., & Soong, R. (2012). Nuclear magnetic resonance spectroscopy and its key role in environmental research. Environmental Science & Technology, 46(21), 11488-11496. https://doi.org/10.1021/es302154w

Vinogradova, O. and Qin, J. (2011). Nmr as a unique tool in assessment and complex determination of weak protein–protein interactions., 35-45. https://doi.org/10.1007/128_2011_216

Wojnarowska, Ż., Grzybowska, K., Hawełek, ᴌ., Dulski, M., Wrzalik, R., Gruszka, I., … & Markowski, J. (2013). Molecular dynamics, physical stability and solubility advantage from amorphous indapamide drug. Molecular Pharmaceutics, 10(10), 3612-3627. https://doi.org/10.1021/mp400116q