Computer optimized spectral aliasing in the indirect dimension of 1H–13C heteronuclear 2D NMR experiments. A new algorithm and examples of applications to small molecules

Improving resolution in single-scan 2D spectroscopy

“…Powerful methods exist to choose a spectral width that is as small as possible without generating any ambiguities due to folding [25][26][27]. If the proton spectrum is unknown, one should repeat the experiment with a slightly different spectral width in the direct x 2 dimension.…”

A new gradient-controlled method for improving the spectral width of ultrafast 2D NMR experiments

“…A straightforward and efficient approach has been developed by Jeannerat [9,10], based on the optimization of spectral aliasing. In this method, 2D peaks are folded along the indirect dimension, resulting in a smaller spectral range to be sampled.…”

“…Unfortunately, the spectral aliasing method described above [9,10] cannot be employed in the k-domain, as Fourier Transform is not applied in the ultrafast dimension. Therefore, Pelupessy et al proposed to add a band-selective refocusing pulse flanked by a bipolar gradient pair before the mixing period to recover signals lying out of the observed range [22].…”

Indirect determination of chemical shift by coupling evolution during adiabatic pulses

“…These include relaxation optimization [1], minimal sampling in the indirect dimension combined with aliasing or specialised processing methods [2][3][4][5][6][7] and reduced dimensionality (projection) methods [2]. These methods all rely on time-dependent intensity-modulation of the directly observed signals which is transformed to produce multidimensional spectra where chemical shifts can be measured from frequency axes.…”