2011/06/15 by Frank H. Köhler · 20 citations
Biochemistry, Genetics and Molecular Biology · Chemistry · Materials Science · #Carbon-13 NMR satellite #Chemical physics #Chemistry #Coalescence (physics) #Condensed matter physics #Diamagnetism #Electron Spin Resonance Studies #Electron paramagnetic resonance #Fluorine-19 NMR #Lanthanide and Transition Metal Complexes #Magnetic field #Magnetism #Magnetism in coordination complexes #NMR spectra database #Nuclear magnetic resonance #Nuclear magnetic resonance spectroscopy #Paramagnetism #Physics #Relaxation (psychology) #Spectral line #Stereochemistry
paper · doi:10.1002/9780470034590.emrstm1229
published in Encyclopedia of Magnetic Resonance
openalex publication_date 2011/06/15 · openalex created_date 2025/10/10 · openalex updated_date 2025/11/06
Whether NMR spectra of paramagnetic complexes can be observed depends most often on the electron relaxation rate. This is because the usually broad and strongly shifted signals originate from the coalescence of the virtual signal pattern generated by the electron-nuclear coupling. A high electron relaxation rate favors NMR spectra; otherwise, EPR is the method of choice. Occasionally, the resonance experiment can be shifted from the NMR to the EPR domain and vice versa. Although the signal widths are larger for diamagnetic compounds, a high spectral resolution is attained because of the large shifts. This renders applications such as the determination of spin densities very precise. From the spectra the molecular structure including the stereochemistry and fluxional behavior can be established similarly to what is known for diamagnetic compounds. Beyond this, properties related to the magnetism can be investigated. Selected examples for magnetic interaction and spin crossover are discussed, and limitations and advantages of the NMR approach are addressed.