OplossingNMR

OplossingNMR, also called solution-state NMR, is a form of nuclear magnetic resonance spectroscopy performed on samples dissolved in a liquid solvent. In solution, rapid molecular tumbling averages many anisotropic interactions, yielding sharp resonances and relatively simple spectra compared with solid-state NMR. It is widely used for structural characterization, assignment, and quantitative analysis of organic molecules, biomolecules, and polymers that are soluble in suitable solvents.

Instrumentation typically involves high-field superconducting magnets, with proton spectra commonly acquired at 400–900 MHz. The 1H nucleus is the most sensitive; 13C, 15N and other nuclei are observed in specialized experiments. Samples are prepared in deuterated solvents (for example CDCl3, DMSO-d6, D2O) to minimize solvent signals and enable field locking. Chemical shifts are referenced to standards such as tetramethylsilane or to residual solvent peaks.

Common experiments include one-dimensional 1H and 13C, and two-dimensional methods such as COSY, HSQC, HMBC, NOESY/ROESY, TOCSY, and DOSY. These experiments support structure elucidation, assignment, and, in some cases, quantitative analysis (qNMR).

Sample preparation considerations include choosing a solvent compatible with solubility and exchange processes, maintaining suitable concentration and temperature, and ensuring the absence of paramagnetic impurities that broaden signals.

In summary, oplossingNMR provides detailed, non-destructive insight into molecular structure and dynamics in solution, and it serves as a foundational tool in chemistry, biochemistry, and materials science.