Console renewal 400 MHz NMR spectrometer with automatic sample changer

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We apply the renewal of a 400 MHz NMR spectrometer using the existing superconducting magnet. The entire electronics ("console") are to be renewed, as well as the automatic sample changer. These components are outdated and prone to failure. Service from the manufacturer for these components is no longer assured ("End of Service" was in 2018 and 2016, respectively). Furthermore, the existing device can only be operated with outdated software that has not been maintained or renewed by the manufacturer since 2015. Therefore, the console and sample changer are to be replaced with new components so that the continued operation of the spectrometer is assured in the coming years.Some of the existing components can continue to be used with the new console, provided that they are compatible with the new instrument. In addition to the superconducting magnet, this concerns the shim system as well as the NMR probes and the cooling devices for measurements at variable temperature. The existing instrument is used for NMR measurements by many research groups at the Inorganic Chemistry Institute and is used to capacity. The typical application is 1D and 2D measurements of diamagnetic compounds of NMR nuclei with high to medium sensitivity such as 1H, 2H, 13C, 19F, 31P, 11B, 119Sn, 7Li. In addition, variable temperature measurements (typical range -90°C to +120°C) are often performed. In addition, measurements of paramagnetic metal complexes are of great importance. Here, a magnetic field strength of 9.4 T (i.e. 400 MHz 1H frequency) represents a good compromise between measurement sensitivity, pulse excitation width, relaxation behavior and signal dispersion. The instrument is embedded in the NMR infrastructure of the two molecular chemistry institutes, the Inorganic and the Organic Chemistry Institute of Heidelberg University (ACI and OCI, respectively). The majority of the samples at the requested instrument come from research groups at the ACI, which are all located in close proximity to the instrument. This allows measurements of very sensitive samples as well as kinetic measurements shortly after reaction start. Measurements that require a much higher sensitivity can be made on the instruments with cryo probes available at ACI and OCI. Working groups of other institutes of Heidelberg University, which need NMR measurements less frequently (e.g. from the Institute of Physical Chemistry or Biochemistry), will also be provided with the requested equipment.