# Overview Signal Amplification by Reversible Exchange (SABRE) is a hyperpolarization technique used in Nuclear Magnetic Resonance (NMR). In this work, we explained the spin order transfer pathways in the SABRE process by conducting several SABRE experiments and performing spin dynamics simulations. # Data The experimental and computational data is found in three different compressed archives: - experimental_data.zip - quantum_chemistry.zip - simulation_data_and_code.zip ## Experimental data This folder contains the output files from the spectrometers. The following abbreviations are used in the folder names: - 1H = Proton experiments - 19F = Fluorine experiments - mFP = 3-monofluoropyridine - dFP = 3,5-difluoropyridine ### Build-up Folder named "buildup" contains the build-up time experiments where the bubbling time was varied between experiments. These experiments were measured on a SpinSolve spectrometer. Example: 230322-130444 Proton (8 mT bubbling 2s). This experiment contains 1H spectrum after 2 seconds of SABRE-hyperpolarization at 8 mT field. ### Exchange Folder named "exchange" contains the experiments that were used to determine the dissociation rate of the 3-fluoropyridine SABRE complex. These experiments were performed on a Bruker spectrometer. Contains: - 20 - 1H spectrum - 21 - 19F spectrum - 22 - Inversion recovery of 1H - 23 - Inversion recovery of 19F - 24 - Selective inversion-recovery (3-fluoropyridine in solution inverted) - 25 - Selective inversion-recovery (3-fluoropyridine at axial position in complex inverted) - 26 - Selective inversion-recovery (3-fluoropyridine at equatorial position in complex inverted) - 27 - Selective inversion-recovery (3-fluoropyridine in solution inverted), additional data points - 28 - Selective inversion-recovery (3-fluoropyridine at axial position in complex inverted), additional data points - 29 - Selective inversion recovery (3-fluoropyridine at equatorial position in complex inverted), additional data points ### Field dependence Folder named "fielddep" contains the SABRE experiments where the polarization transfer field was varied. These experiments were measured on a SpinSolve spectrometer. Example: 230315-132300 Proton (0 µT). SABRE experiment performed at 0 µT. ### OPSY Folder named "opsy" contains the Only Parahydrogen SpectroscopY experiments performed on a SABRE hyperpolarized sample at different magnetic fields. These experiments were performed on a SpinSolve spectrometer. Example: 240604-121335 OPSYd (1 µT). Sample SABRE-hyperpolarized at 1 µT and measured with OPSYd ### Relaxation Folder named "relaxation" contains the SABRE experiments where relaxation times were studied. The sample was hyperpolarized and left for relaxation at varying magnetic fields for different durations. These experiments were performed on a SpinSolve spectrometer. Example: 230316-110628 Proton (8 mT relax 2s). Hyperpolarized sample is left at field of 8 mT for 2 seconds before acquisition. ### Spectra Folder named "spectra" contains high-resolution spectra of a 3,5-difluoropyridine sample measured at high field. These experiments were measured on a Bruker spectrometer. Contains: - 46 - 1H spectrum - 47 - 19F spectrum ### Thermal Folder named "thermal" contains thermal equilibrium references (for calculating the absolute polarization levels of the SABRE-hyperpolarized samples). These experiments were performed on a SpinSolve spectrometer. Example: 230405-085443 Proton (thermal 12x conc). Thermal equilibrium 1H signal of the sample at 12-times higher concentration compared to the SABRE samples. ## Quantum chemistry The quantum chemistry folder includes Turbomole input and output files of the calculation of NMR parameters for the SABRE complexes with mono- and difluoropyridine ligands, as well as for the ligands themselves. ## Simulation data and code Simulated magnetizations have been arranged into several .csv files which are named using a consistent naming scheme. An example: mFP_2L_14s(4)_IC_SRSK_30ps.csv The abbreviations are explained as follows: Molecule: - mFP = monofluoropyridine - dFP = difluoropyridine Number of ligands: - 1L = 1 equatorial ligand - 2L = 2 equatorial ligands Spin system size: - 6s = 6 spins - 7s = 7 spins - 8s = 8 spins - 12s = 12 spins - 14s = 14 spins Basis set size: - (4) = 4 spin order - (6) = 6 spin order - (7) = 7 spin order - (8) = 8 spin order Interactions: - IC = incoherent interactions - SRSK = scalar relaxation of the second kind Correlation time: - 10ps = 10 picoseconds - 30ps = 30 picoseconds - 100ps = 100 picoseconds In addition, certain 14-spin simulations have a tag "thermalized" or "not_thermalized", which refer to the thermalization of the relaxation superoperator. Two files have a tag "lig1" or "lig2". These contain the polarization levels of the individual ligands. Within each .csv file, the data columns have been labeled as such: For monofluoropyridine: - B(T) = polarization transfer field in units of Tesla - F = average polarization of fluorines F3 and F4 - H = sum of the individual proton polarizations: H5/6 + H7/8 + H9/10 + H11/12 - N = average polarization of the nitrogens N13 and N14 - Fz-Hz = sum of the heteronuclear two-spin order terms - Hz-Hz = sum of the homonuclear two-spin order terms - H5/6 = average polarization of protons H5 and H6 - H7/8 = average polarization of protons H7 and H8 - H9/10 = average polarization of protons H9 and H10 - H11/12 = average polarization of protons H11 and H12 - Fz-H5/6z = average of the heteronuclear two-spin order terms F3z-H5z and F4z-H6z - Fz-H7/8z = average of the heteronuclear two-spin order terms F3z-H7z and F4z-H8z - Fz-H9/10z = average of the heteronuclear two-spin order terms F3z-H9z and F4z-H10z - Fz-H11/12z = average of the heteronuclear two-spin order terms F3z-H11z and F4z-H12z - H5/6z-H7/8z = average of the homonuclear two-spin order terms H5z-H7z and H6z-H8z - H5/6z-H9/10z = average of the homonuclear two-spin order terms H5z-H9z and H6z-H10z - H5/6z-H11/12z = average of the homonuclear two-spin order terms H5z-H11z and H6z-H12z - H7/8z-H9/10z = average of the homonuclear two-spin order terms H7z-H9z and H8z-H10z - H7/8z-H11/12z = average of the homonuclear two-spin order terms H7z-H11z and H8z-H12z - H9/10z-H11/12z = average of the homonuclear two-spin order terms H9z-H11z and H10z-H12z For difluoropyridine: - B(T) = polarization transfer field in units of Tesla - F = sum of the individual fluorine polarizations: F3/4 + F5/6 - H = sum of the individual proton polarizations: H7/8 + H9/10 + H11/12 - N = average polarization of the nitrogens N13 and N14 - Fz-Hz = sum of the heteronuclear two-spin order terms - Hz-Hz = sum of the homonuclear two-spin order terms - Fz-Fz = average of the homonuclear two-spin order terms F3z-F5z and F4z-F6z - H7/8 + H11/12 = sum of the individual protons polarizations: H7/8 + H11/12 - H9/H10 = average polarization of the protons H9 and H10 - F3/4z-H7/8z + F5/6z-H11/12z = sum of the averages of the heteronuclear two-spin order terms (F3z-H7z and F4z-H8z) + (F5z-H11z and F6z-H12z) - F3/4z-H9/10z + F5/6z-H9/10z = sum of the averages of the heteronuclear two-spin order terms (F3z-H9z and F4z-H10z) + (F5z-H9z and F6z-H10z) - F3/4z-H11/12z + F5/6z-H7/8z = sum of the averages of the heteronuclear two-spin order terms (F3z-H11z and F4z-H12z) + (F5z-H7z and F6z-H8z) - H7/8z-H9/10z + H9/10z-H11/12z = sum of the averages of the heteronuclear two-spin order terms (H7z-H9z and H8z-H10z) + (H9z-H11z and H10z-H12z) - H7/8z-H11/12z = average of the homonuclear two-spin order terms H7z-H11z and H8z-H12z

2025