NMR-spectrometer (400 MHz) for measurements in the liquid phase

• Subject Area: Chemical Solid State and Surface Research
• Term: Funded in 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 470767093

Liquid-phase NMR spectroscopy is a central analytical method in the area of molecular chemistry, which is applied on a daily basis in any chemical institute. It delivers information about the local environment of NMR-active nuclei and, thus, about the structure of compounds. Because of a stronger focus in research at the Leibniz-University Hannover in the field of chemical material science, organic-inorganic materials and polymers, which is documented by numerous, recent appointments for professor positions, there is now a significantly higher need for NMR-measurements in the liquid phase compared to the past. In addition to higher demand, there are also new scientific tasks, which require equipment with a configuration designed for the particular scientific projects. This involves measurements on compounds containing hetero-elements, which are characterized by low abundance or sensitivity, as well as diffusion measurements. The first liquid-phase NMR spectrometer for chemical material science should be situated in a new central laboratory of the university, cfMATCH (core facility multi-scale analysis techniques for the chemical material science). The machine will, thus, be accessible for a large group of users spanning the entire university. The main unit (400 MHz) allows to measure Lamour-frequencies down to particularly low frequencies (12.5 MHz) because of a combination with a high-performance console and different probe heads, and the possibility to use enlarged sample volumes (10mm). Besides standard nuclei (1H, 13C) one can perform the full width band width suitable for nuclei such as 7Li, 11B, 15N, 19F, 27Al, 29Si, 31P, 57Fe, 103Rh, 105Pd, 111Cd, 119Sn, 151Eu, 157Gd, 183W, 195Pt, and 207Pb. Temperature-dependent effects and kinetics can be investigated using the temperature adjustment of the probe heads in the range -100°C till +150°C. Diffusion ordered spectroscopy (DOSY) can be performed in a magnet field gradient in z-direction of up to 50 G/cm. The advantage of such a relatively high field gradient is that it enables the study of compounds with large hydrodynamic radius and, thus, small diffusion rates. The measurement of confined diffusion processes is possible as well.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: NMR-Spektrometer (400 MHz) für Messungen in flüssiger Phase
• Instrumentation Group: 1740 Hochauflösende NMR-Spektrometer
• Applicant Institution: Gottfried Wilhelm Leibniz Universität Hannover
• Leader: Professor Dr. Sebastian Polarz