High-field NMR with dissolution triplet-DNP.

Dissolution dynamic nuclear polarization (DNP) has wide variety of important applications such as real-time monitoring of chemical reactions and metabolic imaging. We construct DNP using photoexcited triplet electron spins (Triplet-DNP) apparatus combined with dissolution apparatus for solution NMR in a high magnetic field. Triplet-DNP enables us to obtain high nuclear polarization at room temperature.

Dynamic Nuclear Polarization using Photoexcited Triplet Electron Spins in Eutectic Mixtures.

Dynamic nuclear polarization using photoexcited triplet electrons (Triplet-DNP) is a method to significantly enhance nuclear spin polarization even in a low magnetic field and at room temperature. Pentacene has been practically used as an efficient polarizing agent for Triplet-DNP. In this study, we demonstrate room temperature H and C hyperpolarization of eutectic mixtures of deuterated benzoic acid doped with pentacene and a target molecule such as salicylic acid, nicotinic acid, or 2-naphthoic acid.

Determination of nuclear quadrupolar parameters using singularities in field-swept NMR patterns.

We propose a simple data-analysis scheme to determine the coupling constant and the asymmetry parameter of nuclear quadrupolar interactions in field-swept nuclear magnetic resonance (NMR) for static powder samples. This approach correlates the quadrupolar parameters to the positions of the singularities, which can readily be found out as sharp peaks in the field-swept pattern. Moreover, the parameters can be determined without quantitative acquisition and elaborate calculation of the overall profile of the pattern.

Hydride in BaTiO2.5H0.5: A Labile Ligand in Solid State Chemistry.

In synthesizing mixed anion oxides, direct syntheses have often been employed, usually involving high temperature and occasionally high pressure. Compared with these methods, here we show how the use of a titanium perovskite oxyhydride (BaTiO2.5H0.

Paramagnetic shimming for wide-range variable-field NMR.

We propose a new passive shimming strategy for variable-field NMR experiments, in which the magnetic field produced by paramagnetic shim pieces placed inside the magnet bore compensates the inhomogeneity of a variable-field magnet for a wide range of magnet currents. Paramagnetic shimming is demonstrated in (7)Li, (87)Rb, and (45)Sc NMR of a liquid solution sample in magnetic fields of 3.4, 4.

Elemental analysis by NMR.

We explore the possibility for elemental analysis by NMR. To keep the efficiency of the signal acquisition common for all spin species, we propose to fix the frequency and vary the magnetic field to cover the isotopes involved in a sample. We introduce constant-frequency receptivity for quantitative elemental analysis in the frequency-fixed NMR experiment.