Solid-state NMR spectroscopy of half-integer quadrupolar metals has received a lot of interest recently with the advent of new methodologies and higher magnetic fields. We present here the extension of our previous low temperature method to an 18.8 T system. This new probe entailed a total redesign including a cross coil and variable capacitors that are operational at cryogenic temperatures. The limitations to sensitivity are also discussed; including a new diode network, the utilization of a cryogenic band pass filter, and the consequences of the RF profiles of the coil. Further, details of the spectroscopy of a spin 5/2 metal in a protein are discussed, such as the observation of the outer transitions and how to distinguish them from the desired ±1/2 transition
Revised: March 25, 2011 |
Published: March 1, 2004
Citation
Lipton A.S., R.W. Heck, J.A. Sears, and P.D. Ellis. 2004.Low Temperature Solid-State NMR Experiments of Half-Integer Quadrupolar Nuclides: Caveats and Data Analysis.Journal of Magnetic Resonance 168. PNWD-SA-6205.