RELIABLE 2-DIMENSIONAL ROTATING-FRAME CROSS-RELAXATION MEASUREMENTS IN COUPLED SPIN SYSTEMS

A new and extremely useful variant of rotating-frame Overhauser effect spectroscopy, which is termed T-ROESY, is discussed. It has the distinct advantage of almost completely removing TOCSY cross peaks from the spectrum and can be implemented to deliver phase-sensitive two-dimensional spectra. The thinking that led to the T-ROESY sequences is described, focusing on a geometrical picture of how TOCSY occurs. Experimental results, presented for a hydrocarbon-like alkaloid containing many coupled protons within a narrow spectral bandwidth, agree with the simplified calculations. © 1993 Academic Press, Inc.