600-MHz-NMR spectrometer (3 frequency channels)

• Subject Area: Molecular Chemistry
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 553332459

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. The application is for a 600 NMR MHz spectrometer with 3 frequency channels, 2 triple resonance probes [1. Broadband observe 31P-109Ag & 19F/31P/1H, 2. Broadband observe 31P-109Ag & 19F/19F/1H), temperature control equipment (cooling unit, low-temperature accessories) and automatic sample changer for the best possible utilization. It is intended to replace the 16-year-old 2-channel 400 MHz device used by the service. Due to its indispensable unique features, this still serves as the main device for measurements at variable temperatures (VT, usually up to –110 °C) and double resonance experiments of type 19F/1H. Due to its age, it is extremely unreliable (especially for VT), prone to repairs and technically outdated, and spare parts are extremely tricky to obtain. The lack of sensitivity severely limits the study of labile substances below -40 °C (minimum temperature of the cryo heads of the other two service devices) due to excessively long measurement times. It thus no longer meets the requirements of the service. Increasing the 1H frequency of the requested replacement device to 600 MHz, together with the intended equipment, will bring the following improvements: significantly higher detection sensitivity with maximum flexibility in terms of temperature (–120 to +150 °C), state-of-the-art, needs-based expansion of the experimental portfolio. Unstable organometallic samples that require temperatures below –40 °C can then be studied more easily. Not only will time-saving multi-receive experiments then be possible, but also routine triple resonance measurements with 1H and simultaneous 31P or 19F decoupling, for which 3 frequency channels are necessary. These measurements are also very useful because of the additional sensitivity gain due to the collapse of multiplets. This application is related to a parallel application for new electronics for the 400 MHz NMR instrument so that it can be used as an open access device in the future and, in turn, as a replacement for the oldest and most dilapidated 300 MHz instrument which should be decomissioned.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: 600-MHz-NMR-Spektrometer (3 Frequenzkanäle)
• Instrumentation Group: 1740 Hochauflösende NMR-Spektrometer
• Applicant Institution: Technische Universität Braunschweig
• Leader: Dr. Kerstin Ibrom