NMRESRspektroskopi

NMRESRspektroskopi is an interdisciplinary spectroscopy approach that combines Nuclear Magnetic Resonance (NMR) and Electron Spin Resonance (ESR) techniques to study chemical systems containing unpaired electrons. The goal is to obtain a more complete picture of molecular structure, electronic environment, and dynamics than can be achieved with either method alone.

Principles rely on complementary information from nuclear spins, accessed by NMR, and electron spins, probed by ESR. NMR senses chemical shifts, scalar and dipolar couplings between nuclei, and molecular dynamics on nanosecond to second timescales, whereas ESR provides g-values, hyperfine couplings, and details of unpaired electron distribution. By correlating data from both spin manifolds, NMRESRspektroskopi can yield distances between nuclei and electron spins, spin density maps, and information about excited states and reaction intermediates.

Techniques commonly employed include electron-nuclear double resonance (ENDOR), electron spin echo envelope modulation (ESEEM), and related cross-relaxation experiments, as well as advanced pulsed methods for transferring polarization between electrons and nuclei. Instrumentation may use integrated hybrid spectrometers or coordinated sequences on separate NMR and EPR instruments, often requiring cryogenic temperatures and specialized resonators for both RF and microwave frequencies.

Applications cover bioinorganic chemistry, metalloproteins and radical enzymes, catalytic systems, organic and inorganic magnets, and materials science. The field faces challenges such as spectral congestion, sensitivity limitations, and the need for sophisticated data analysis and simulations to extract reliable structural and dynamical parameters. Ongoing research aims to improve instrumentation, multimodal data fusion, and quantitative interpretation of NMRESRspektroskopi results.