Speaker
Description
Nuclear spin hyperpolarization uncouples the magnitude of spin magnetization from that of an externally applied magnetic field, making NMR and magneto-optical measurements possible over a wide range of field strengths. In this presentation, we use dissolution dynamic nuclear polarization (D-DNP) and para-hydrogen induced polarization (PHIP) for measurements of NMR and nuclear spin optical rotation (NSOR). Low-field, milli-Tesla NMR accesses a different regime of molecular dynamics than the Tesla range magnetic fields frequently used for NMR in Chemistry and Biochemistry. We illustrate the application of cross- and R2 relaxation measurements for the study of molecular interactions of small molecules and small-molecule ligands with biological macromolecules. Thereby, signals of hyperpolarized 1H and 19F spins are detected inductively, in single scans, at Larmor frequencies between ~10-100 kHz. At the same magnetic field, optical signals from a specific location within a molecule can be addressed through NSOR, by radio frequency pulses acting on nuclear spins. The NSOR effect holds promise for creating a combined optical/NMR spectroscopy with site selectivity in a molecule. NSOR may further be used for a readout of spin coherence with spatial localization by a focused optical beam, as may be required for future quantum information science applications of NMR. NSOR signals from single quantum coherences are observable in dilute solution with 1H and 19F spin hyperpolarization generated by D-DNP. We measure NSOR constants of trifluoroethanol and dimethyl sulfoxide at 405 nm, where the latter molecule at the otherwise required high concentration would exhibit prohibitive optical absorption.
