Upgrade 400-MHz-NMR spectrometer

• Subject Area: Molecular Chemistry
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 553332409

The Central NMR Laboratory of the Chemical Institutes of the TU Braunschweig (joint facility of the Institute for Inorganic and Analytical Chemistry and the Institute for Organic Chemistry) has been providing NMR spectroscopic services and know-how across the university since 1987. Around 40,000 experiments are carried out annually on the 5 NMR spectrometers which are equipped with automatic sample changers to ensure optimal use in 24-hour operation.3 NMR spectrometers (600, 500, 400 MHz) are reserved for use by the laboratory's specialist staff, who carry out experiments on them for scientists from across the university. A further 2 (300 MHz) are used for self-service by the employees of 6 institutes. One of the two has a number of persistent defects due to its age (electronics, magnet, sample changer: 19, 35 and 37 years of age, respectively) and urgently needs to be replaced.In its place, the 400 MHz device currently used as a service device will be put into open-access operation. Although it is already 16 years old, and therefore extremely unreliable and prone to repairs, it has a number of indispensable unique and selling points. As such, it has so far been used as the main device for measurements at variable temperatures below –40 °C (lowest achievable temperature of the cryo heads of the other two service devices) and for double resonance experiments of type 19F/1H. The fact that the sensitivity is now significantly too low, which severely limits the study of unstable substances at low temperatures, argues against the 400 MHz device remaining in service after it has been partially replaced with new electronics. However, together with a new console, the magnet is ideally suited for years of continued self-service use.With the intended upgrade, the 400 MHz spectrometer is intended to undergo a change in use, becoming a self-service instrument that can replace the dilapidated oldest 300 MHz NMR device. The latter can then be decommissioned.The following components are therefore requested: 400 MHz NMR spectrometer electronics (2 frequency channels), broadband observation probe head 31P-109Ag, 19F/1H, equipment for temperature control around room temperature and automatic sample changer for the best possible utilization.This will bring about the following improvements of the self-service facility: shorter experiment duration, especially with 13C, due to higher magnetic field strength and thus greater measurement capacity in self-service, 19F will then be observable on both open access devices, increased reliability, adaptation to the current state-of-the-art.As the 400 MHz instrument, currently used as a service device, must be replaced in service, this application is related to a parallel application for a 600 MHz NMR spectrometer.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Upgrade 400-MHz-NMR-Spektrometer
• Instrumentation Group: 1740 Hochauflösende NMR-Spektrometer
• Applicant Institution: Technische Universität Braunschweig
• Leader: Dr. Kerstin Ibrom