Hadamard acquisition of ¹³C–¹³C 2‐D correlation NMR spectra

Abstract

We show that a multiselective excitation with Hadamard encoding is a powerful tool for 2-D acquisition of 13 C─ 13 C homonuclear correlations. This method is not designed to improve the sensitivity, but rather to reduce the experiment time, provided there is sufficient sensitivity. Therefore, it allows fast acquisition of such 2-D spectra in labeled molecules. The technique has been demonstrated using a U─ 13 C─ 15 N histidine hydrochloride monohydrate sample allowing each point of the build-up curves of the 13 C─ 13 C cross-peaks to be recorded within 4 min 35 s, which is very difficult with conventional methods. Using the U─ 13 C─ 15 N f-MLF sample, we have demonstrated that the method can be applied to molecules with 14 13 C resonances with a minimum frequency separation of 240 Hz.

Applications of alternative sampling methods

“…These include reaction monitoring, where 1D and 2D approaches are critically compared by Gołowicz et al [1] and Steimers et al [2] , who demonstrate the strengths and weaknesses of both. Further, the applications of alternative sampling in the solid-state, where NMR experiments are still usually performed in a classical manner, are described by Porat et al [3] and Paluch et al [4] The former describes the acceleration of high-dimensional (4D) acquisition, while the latter the application of the Hadamard approach. Also, medical applications are described, including Hoyt et al [5] and Szigetvári et al [6] discussing the applications of NUS in the pharmaceutical industry, while Jeeves et al [7] and Joseph et al [8] show how NUS can be useful in metabolomics.…”