Optimizing sensitivity and resolution in time-shared NMR experiments.

An improved approach to optimize the overall sensitivity and the resolution requirements in the indirect dimension of (13)C/(15)N time-shared (TS) NMR experiments is presented. A different data sampling acquisition procedure is applied for (13)C and (15)N in the indirect dimension, and a proper data recombination before conventional data processing allows a customized adjustment of spectral widths, number of scans and number of increments individually for (13)C and (15)N. The major benefit is an important improvement on the detection limits of the TS experiment that overcomes the lower sensitivity of (15)N over (13)C at natural abundance. We evaluate such enhancements from 2D TS-HMBC experiments recorded on a nitrogen-containing synthetic azole derivative of pharmaceutical interest.