Nuclear magnetic resonance is a technique that allows the measurement of the nanoscale distances between the atoms of a molecule. It is often relied upon for finding the structure of a molecule and how atoms are bonded, but measurements become inaccurate for large distances and therefore for large biological molecules. This research presents a new software for calculating the distances between nuclei and unpaired electrons which offers more accurate long-range distances in biological molecules.

This paper analyzes a commonly used line-narrowing mechanism (homonuclear decoupling) in solid-state NMR and discusses what limits the achievable line width. Based on theoretical considerations, the contribution of different effects to the line width is discussed and a new contributing term is identified. This research allows us to evaluate new ways to improve the line width in such homonuclear decoupled spectra.

Detailed interpretation of brain MRI data is hampered by the fact that each imaging voxel comprises several types of cells and tissues. To address this, we adapt signal encoding and data inversion strategies from solid-state and low-field NMR to quantify the sub-voxel heterogeneity of the human brain with 5D relaxation–diffusion distributions wherein distinct tissue components are resolved, individually characterized, and subsequently mapped throughout the volume of the brain.

DNP is a method used to enhance NMR signals by transferring polarization from radicals to nuclear spins using microwave irradiation. The EPR spectrum of the radical during the irradiation is determined by a process called spectral diffusion and affects the DNP efficiency. This process can be measured by electron–electron double resonance. We explored experimentally and theoretically the contribution of the hyperfine coupling of the ¹⁴N nuclei in the nitroxide radical to the spectral diffusion.

The determination of distance distributions in the nanometre range is an important application of pulsed electron paramagnetic resonance spectroscopy. However, low sensitivity is often a major challenge. In this paper, we compare several broadband-shaped pulses and compare their performance to classical rectangular pulses in order to increase the sensitivity of double electron–electron resonance to a commercial setup. We show that improvements in sensitivity of up to 86 % are possible.

Measuring distances between unpaired electron spins is an important application of electron paramagnetic resonance. The longest distance that is accessible is limited by the phase memory time of the electron spins. Here we show that strong continuous microwave irradiation can significantly slow down relaxation. Additionally, we introduce a phase-modulation scheme that allows measurement of the distance during the irradiation. Our approach could thus significantly extend the accessible distances.

A dipolar cross-polarization (dCP) sequence employing simple radiofrequency pulse shapes with reduced power requirements is demonstrated to transfer proton polarization to insensitive heteronuclei.