Easy access to in-situ HP (high pressure)-NMR data
To proceed in the understanding of homogeneous catalysis, detailed knowledge on catalyst structures and intermediates as well as reaction kinetics is necessary. For reactions involving gaseous substrates, commercially available solutions which adopt analytical methodology to conditions of pressure reactions are rare. We have developed a new experimental setup to get easy access to reliable HP-NMR spectroscopic data.1 The HP-NMR tube was designed as a flow cell which allows for quick saturation of the sample solution with gases. Control and adjustment of gas flow and pressure, respectively, as well as the switch to another gaseous reactand is perfomed by use of a gas recycling unit (see figure 2) while the NMR tube remains in the position for measurement. Variable temperature measurements can be performed as usual. The setup is designed for the use in the routine NMR lab equipped with a 10 mm probe head. There is no need to make changes to the given magnet or NMR probe, respectively. We now have an mechanically more reliable NMR-cell available,2 we have used this Equipment to characterize intermediates in Rhodium catalysis 3,4 and within other fields of research5.
If you are interested to apply this methodology: The gas circulation system, together with the appropriate flange-capillary set to feed a 10 mm sapphire HP-NMR tube, is commercially available. Please contact Warnow Hydraulik, Rostock.
1. D. Selent, W. Baumann, A. Börner, DE 10333143.3 (17.07.2003, IfOK Rostock)
2. G. Walther, A. Köckritz. A. Martin, D. Selent, DE 102011007527 (15.04.2011. LIKAT Rostock)
3. D. Selent, R. Franke, C. Kubis, A. Spannenberg, W. Baumann, B. Kreidler, A. Börner, Organometallics
2011, 30, 4509-4514.
4. C. Kubis, D. Selent, M. Sawall, R. Ludwig, K. Neymeyr, W. Baumann, R. Franke, A. Börner, Chemistry-A
European Journal 2012, 18, 8780-8794.
5. T. Schulz, C. Färber, M. Leibold, C. Bruhn, W. Baumann, D. Selent, T. Porsch, M. C. Holthausen, U.
Siemeling, Chem. Comm. 2013, 496834-6836.