A high-pressure NMR probehead for measurements at 400 MHz

Abstract

A new high-pressure NMR probehead designed for a 400 MHz widebore NMR spectrometer is described. For the first time, the electrical leads of the rf circuit, the tubes for the thermostating liquid and the high-pressure 'fluid, as well as the wires of the Pt-100 resistor for temperature control, are all fitted at the bottom of the high-pressure vessel. The sample can easily be removed through a top plug, which allows a relatively fast exchange of the sample. A rather simple design leads to a low-cost construction. The high-pressure vessel and the rf circuit are placed inside a standard probehead jacket, such that the high-pressure probehead can be fitted into the superconducting magnet in the same way as a commercial probehead.

Ligand Exchange Processes on Solvated Lithium Cations: Complexation by Cryptands in Acetone as Solvent

“…A homemade high-pressure probe described in the literature [46] was used for the variable-pressure experiments which were conducted at a selected temperature and at ambient, 30, 60, 75, 90, 120 and 150 MPa pressure. A standard 5-mm NMR tube cut to a length of 45 mm was used for the sample solution.…”

A High-Pressure, High-Resolution NMR Probe for Experiments at 500 MHz

“…Inclusion of a porcelain chip capacitor inside the pressure vessel with a long-lasting, high-strength Berylco feedthrough helped alleviate concerns about durability, but at best could only offer a sensitivity comparable to our previous 300-MHz NMR pressure probes. Excluding our own probes, the highest reported frequency for an autoclave-style pressure vessel has been 400 MHz, although with limited pressure ranges of only ϳ2 kbar (6,7).…”

The impact of tripodal chelates on water exchange kinetics and mechanisms: A variable temperature and pressure 17O NMR study to clarify the structure-reactivity relationship in [FeII(L)(H2O)2]− complexes

“…The line width at half height of the signal were determined by a deconvolution procedure on the real part of the Fourier transformed spectra with a Lorentzian shape function in the data analysis module of Bruker Topspin. For variable pressure measurements a homemade thermostated high-pressure probe [11] was applied, in which the sample was placed in a standard 5-mm NMR tube that was cut to a length of 50 mm and closed with a moveable macor piston. The pressure was transmitted to the sample by pressurizing the surrounding perfluorated hydrocarbon (hexafluoropropylene oxide, Hostinert 175, Hoechst).…”