Long‐range two‐dimensional heteronuclear chemical shift correlation

Abstract

Abstract Long‐range heteronuclear chemical shift correlation has undergone a period of burgeoning growth during the past 4 years. Initially, such correlations were made by simply reoptimizing the conventional heteronuclear chemical shift correlation sequence originally devised by Freeman and Morris. Problems inherent in the reoptimization of the Freeman–Morris sequence have led to the development of a number of other of experiments, most recently, including reverse (proton) detected heteronuclear multiple quantum techniques. The techniques now in use are compared and the inherent problems of each are identified and weighed against advantages. Applications of each technique are also presented.