400 MHz NMR Spectrometer

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We request the procurement of a new 400 MHz NMR spectrometer with N2 cryo-probe head including superconducting magnet, console, sample changer and temperature control unit for measurements at variable temperature (VT). The instrument will replace two 200 MHz NMR spectrometers (years of procurement: 1987 and 2001). The instruments to be replaced are no longer practical due to high susceptibility to faults, lack of repair facilities, outdated software and low field strength. Outdated electronics and the lack of gradient-selected experiments prevent contemporary molecular chemical structural analysis. At the same time, there is a large increase in the number of samples in the faculty due to new appointments. Existing NMR spectrometers (see utilization concept) cannot meet the demand for routine measurements as well as longer measurements, e.g. at variable temperature or kinetic studies. The proposed spectrometer will be operated as a "walk-in" routine instrument for the measurement of a large number of samples, with the cryo-probe head ensuring high sensitivity for a variety of NMR-active nuclei. The research groups involved use liquid-phase NMR spectroscopy as the core analytical method. This results in a sample volume of sometimes >100 measurements per day. The typical application of the new instrument will be the 1D and 2D measurement of nuclei with high to medium sensitivity, such as 1H, 2H, 13C, 15N, 19F, 29Si, 31P, 11B, 119Sn, 7Li. In particular, the measurement of less sensitive nuclei such as 29Si will be greatly enhanced by equipping the instrument with the cryo-sample head, and will provide insights into the structural chemistry of reaction intermediates as well. Likewise, the instrument will be used to measure reaction kinetics and molecular dynamics, and thus contribute decisively in the field of elucidating reaction mechanisms of predominantly main group element-based systems. Besides the research groups at the Inorganic-Chemical and the Organic-Chemical Institute, also working groups e.g. from the Physical-Chemical Institute or from Biochemistry are served by this instrument pool. The new instrument is operated by flexibly bookable measurement times via an online booking system and an efficient sample changer, so that numerous samples in routine operation or planned longer measurements can be coordinated 24/7.