A High-Pressure NMR Probe for Aqueous Geochemistry.

Angewandte Chemie (International ed. in English)

PubMedID: 24989120

Pautler BG, Colla CA, Johnson RL, Klavins P, Harley SJ, Ohlin CA, Sverjensky DA, Walton JH, Casey WH. A High-Pressure NMR Probe for Aqueous Geochemistry. Angew Chem Int Ed Engl. 2014;.
A non-magnetic piston-cylinder pressure cell is presented for solution-state NMR spectroscopy at geochemical pressures. The probe has been calibrated up to 20 kbar using in situ ruby fluorescence and allows for the measurement of pressure dependencies of a wide variety of NMR-active nuclei with as little as 10 µL of sample in a microcoil. Initial (11) B NMR spectroscopy of the H3 BO3 -catechol equilibria reveals a large pressure-driven exchange rate and a negative pressure-dependent activation volume, reflecting increased solvation and electrostriction upon boron-catecholate formation. The inexpensive probe design doubles the current pressure range available for solution NMR spectroscopy and is particularly important to advance the field of aqueous geochemistry.