Upgrade 600-MHz-NMR Spectrometer

“化学研究所核磁共振中心实验室”是位于布伦斯韦格理工大学的无机化学和分析化学研究所以及有机化学研究所的联合设施。它在整个大学提供核磁共振波谱服务和技术诀窍。考察了在该大学的化学、生物、制药和材料科学研究所获得或制造的天然物质以及有机、无机、有机金属和高分子合成产品。到目前为止，在这里提供的五台核磁共振光谱仪中，最灵敏的是一台600 MHz的设备，它带有一个氦冷却的反向三谐振低温探头(1H/13C/15N；仅间接15N)。由于探针头及其外围设备在大约由于工作时间为110,000个小时(2006-2019年)，光谱仪不再履行其主要目的，即检查具有最高检测灵敏度的样品。因此，光谱采集需要之前测量时间的数倍，或者对于非常少量的物质是无用的。这导致了严重的容量问题，间接地也对其他光谱仪，特别是500 MHz设备造成了严重的容量问题。为了恢复性能并使600 MHz光谱仪现代化，有必要对该设备进行部分更换。虽然磁铁和一个探头(不是冷冻头：宽带观察仪31P-15N/1H)将继续使用，但我们打算更换已有14年历史的光谱仪控制台(技术上已过时；存在严重的备件问题；已宣布于2017年底“服务终止”)，包括自动换样器和有缺陷的低温设备。后者包括低温制冷机组、氦气压缩机、氦气冷却反三谐振式低温探头和合适的温度控制方案。需要新的部件至少恢复原有装置的全部性能。因此，和以前一样，重点放在最高的1H灵敏度上，同时，为了与其他光谱仪互补，还要尽可能地提高13C和15N的灵敏度。考虑到工作组的多样性，以前的设备(如19F不可观测；15N不可直接观测；低温探头的温度范围太小，0-80°C)应予以消除。因此，我们申请以下部件：600 MHz三通道光谱仪控制台，氦冷却反向三谐振低温探头(1H和19F/13C/15N；15N还可直接观察到)最大的温度范围，自动换样器，以优化设备的使用。其结果将是：恢复最高灵敏度(极其重要)，最先进的核磁共振实验的可行性(例如诺亚)；直接观测19F和15N；可接近的温度范围-40至+150°C。

The "Central NMR Laboratory of the Chemical Institutes" is a joint facility of the Institute of Inorganic and Analytical Chemistry and the Institute of Organic Chemistry at the TU Braunschweig. It provides NMR-spectroscopic services and know-how throughout the university. Natural substances as well as organic, inorganic, organometallic and macromolecular synthesis products are examined, which are obtained or manufactured in the chemical, biological, pharmaceutical and materials science institutes of the university. So far, the most sensitive of the five NMR spectrometers available here has been a 600 MHz device with a He-cooled inverse triple resonance cryo probe (1H/13C/15N; 15N only indirectly). Due to total damage to the probehead and its peripheral devices after approx. 110,000 operating hours (2006-2019), the spectrometer no longer fulfills its main purpose, namely the examination of samples with maximum detection sensitivity. As the consequence, spectra acquisitions require a multiple of the previous measurement time or are useless for very small amounts of substance. This causes severe capacity problems, indirectly also on the other spectrometers, especially on the 500 MHz device. To restore the performance and modernize the 600 MHz spectrometer, a partial replacement of the device is necessary. While the magnet and one probehead (not a cryo head: broadband observe 31P-15N/1H) will remain in use, we intend to replace of the 14-year-old spectrometer console (technically outdated; with serious spare parts problems; “end of service” announced already for the end of 2017) including the automatic sample changer and the defective cryo equipment. The latter include cryo cooling unit, He compressor, He-cooled inverse triple resonance cryo probehead with a suitable temperature control option.New components are required that restore at least the full performance of the original device. Therefore, as before, the focus is on maximum 1H sensitivity and, at the same time, the highest possible 13C and 15N sensitivity in order to complement the other spectrometers. In view of the diversity of the working groups, weaknesses of the previous equipment (e.g. 19F not observable; 15N not directly observable; temperature range of the cryo probehead too small, 0-80 °C) should be eliminated.We therefore apply for the following components: 600 MHz spectrometer console with three frequency channels, cryo equipment with He-cooled inverse triple resonance cryo probe head (1H&19F/13C/15N; 15N also directly observable) for the largest possible temperature range, automatic sample changer for optimal use of the device .Resulting improvements will be: restoration of maximum sensitivity (extremely important), feasibility of state-of-the-art NMR experiments (e.g. "NOAH"); direct observation of 19F and 15N; accessible temperature range -40 to +150 ° C.