Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful and non-destructive analytical technique that has revolutionized organic chemistry since the mid-20th century. Widely used for determining the structure and characterization of organic, inorganic, and biological molecules, NMR offers unique advantages over methods like X-ray crystallography, particularly in resolving three-dimensional structures of biological molecules. Before its advent in 1955, organic compound structures were deciphered through chemical tests and degradations. NMR provides detailed information through parameters such as chemical shifts, coupling constants, and relaxation times, making it invaluable in fields like chemistry, biology, and medicine for studying time-dependent phenomena like conformational changes and chemical exchange.
The Nuclear Magnetic Resonance (NMR) Facility in the Department of Chemistry and Biochemistry at the University of Oklahoma consists of five solution NMR spectrometers (400 MHz VNMRS, 500 MHz VNMRS, 600 MHz Varian, 400 MHz JEOL, and 500 MHz JEOL).
These instruments are open access to all research groups at the University of Oklahoma and throughout the state of Oklahoma. Users within the Department of Chemistry and Biochemistry have access to the NMR Facility twenty-four hours a day, seven days a week.
The main goal of the NMR Facility is to provide timely access and necessary training to all relevant research groups to support the rapid development of their research programs.
Approximately half of the ninety graduate students in the department routinely use NMR spectrometers, and all B.S. chemistry majors obtain experience with NMR in their advanced laboratory courses. The sustainability of the NMR is, therefore, essential to the success of the department and the success of the faculty and their students and post-doctoral researchers.
Nuclear Magnetic Resonance Spectroscopy (NMR) has no doubt been the most influential physical method in organic chemistry during the second half of the 20th century.
Nowadays, NMR spectroscopy is probably the single most indispensable and non-destructive physical method available to a chemist. It is primarily used to determine the molecular structure and identity of compounds, including identifying functional groups and analyzing complex mixtures, making it a crucial tool for research in fields like organic and biochemistry, pharmaceuticals, materials science, and, where detailed molecular structure information is essential.
It should be noted that NMR spectroscopy, along with X-ray diffraction and cryo-electron microscopy, is one of the three main experimental techniques for obtaining three-dimensional structures of biologically important molecules such as proteins, enzymes, DNA, etc.
Unlike other forms of spectroscopy (UV, IR and MS), where either too little or more information is obtained about the structure of the organic compounds being studied, while the analysis of NMR data provides unambiguous structure identity.
The parameters obtained from NMR spectra (chemical shifts, coupling constants, intensities, relaxation times and diffusion coefficients) provide the necessary information for solving a wide variety of problems in chemical and biological sciences.
Some of the most prominent applications of NMR to solve problems involving time-dependent phenomena are conformational analysis, rotational isomerism, restricted (or hindered) rotation, and rapid chemical exchange occurring in organic, organometallic, polymers, and biomolecules.
Following is a general overview of the main applications of NMR spectroscopy.
Identifying the connection of atoms within a molecule, including the presence of specific functional groups like alkenes, alkynes, carbonyl groups, and aromatic rings.
Tracking the progress of a chemical reaction by observing changes in NMR spectra over time. Combined with mass spectrometry, NMR is indispensable in the synthesis of molecules. It is how scientists know exactly what they have made; and how they determine whether a reaction is completed or not.
Conformational and stereochemical analysis refers to the study of a molecule's three-dimensional structure, specifically examining how the atoms are arranged in space and how different spatial arrangements (conformations)
Determination of the relative amounts of various components in a mixture from the intensity of NMR signals and quantification of the percentage composition of a complex mixture using an internal standard.
Assessing the purity of a compound by identifying potential impurities based on their characteristic NMR signals.
Determining the structure and molecular weight of polymers by analyzing their NMR spectra.
Analyzing the three-dimensional structure and dynamics of proteins, nucleic acids, and other biological molecules using advanced NMR techniques.
Identifying and quantifying small molecules (metabolites) within a biological system to study metabolic pathways. This is the study of metabolites, the chemicals produced by the cells of every plant and animal. NMR can identify all metabolites simultaneously and study them noninvasively.
Pharmaceutical industry
NMR spectroscopy is frequently used in pharma workflows, particularly in drug discovery, drug development and ADME (Absorption, distribution, metabolism, and excretion) which are the internal processes that describe how a drug moves throughout and is processed by the body.
Checking the chemical composition and condition of foods, their ingredients and the quality of food products, including fat content and moisture levels.
NMR can identify the origin of illegal drugs or counterfeit drugs based on their composition.
Using NMR principles to generate detailed anatomical images of almost every internal structure in the human body, including the organs, bones, muscles and blood vessels.
