300 MHz NMR Spectrometer

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The MagRes network of the Albert Ludwig University Freiburg requires a 300 MHz NMR spectrometer with a "standard bore" magnet (SB) at the "Institute of Physical Chemistry" (IPC) site. The 300 MHz NMR spectrometer applied for, together with a 600 MHz NMR spectrometer, forms the main research NMR instrumentation at the MagRes site at the IPC. Mostly liquid NMR experiments are carried out there, with a much smaller proportion of solid-state NMR experiments. The main focus is on extensive investigations of light-induced paramagnetic intermediates using the photo-CIDNP method (CIDNP: (photo-)chemically induced dynamic nuclear polarisation) using a special in-situ illumination apparatus. With the simultaneous availability of pulse and continuous-wave lasers (cw lasers) for sample excitation, the NMR devices at the IPC within the MagRes network offer all interested users of the Albert-Ludwigs-University of Freiburg the unique possibility to perform in-situ light-induced NMR experiments, e.g. to investigate the kinetics of photoreactions NMR spectroscopically or to start chemical reactions triggered by light. The 300 MHz NMR instrument applied for is a replacement for an existing 300 MHz NMR spectrometer that has been in operation since 1987; a console was replaced in 1997. The old instrument is extremely susceptible to faults and no longer permits controlled measurement operation. The availability of spare parts can no longer be guaranteed by the manufacturer. In recent years, it has been possible to obtain used spare parts from other NMR sites at considerable cost in terms of time and money; however, repairs have always resulted in only a short-term solution to the problems. In addition, the high evaporation rates for helium and nitrogen of the magnet, which has been in operation since 1987, lead to very high maintenance costs due to the constantly rising price of liquid helium. Therefore, a complete spectrometer is applied for.