Directed TOCSY, a method for selection of directed correlations by optimal combinations of isotropic and longitudinal mixing

The directed TOCSY pulse sequence element transfers coherence predominantly into ''forward-directed'' antiphase coherences while simultaneously suppressing in-phase and ''backward-directed'' antiphase coherences. This novel selection principle, based on the ''direction'' of the target coherences, provides a new approach for the simplification of crowded spectra. In this article, the theory of directed TOCSY is presented for linear spin systems that are frequently found in carbon-labeled biomolecules. (C) 1996 Academic Press, Inc.