In this project in the Experimental Physical Chemistry Program of the Chemistry Division, Shaka will develop a new pulsed nuclear magnetic resonance (NMR) technique called excitation sculpting. Strong DC magnetic pulsed field gradients (PFGs) will be used in conjunction with frequency sweeps to eliminate out-of-band signals, revealing the desired excitation profile and resulting in significant advantages compared to conventional pulse shaping. Preliminary results show effective water suppression using the new technique, in which protons bound to carbon-12 nuclei are suppressed without loss of the desired signal from protons bonded to a carbon-13. Combined with superior carbon-13 decoupling, superb high-resolution absorption-mode proton multiplets are obtained. Nuclear magnetic resonance spectroscopy is one of the most useful tools in the chemist's arsenal. Techniques are constantly being developed which allow this method to be applied to more problems, so that more information can be extracted from NMR spectra with respect to such varied systems as inorganic materials and biologically important molecules. The excitation sculpting method being developed in this work is expected to have a large impact on most important NMR experiments, including some `routine` experiments carried out in NMR facilities everywhere.
