Premium
Coherent and incoherent magnetization transfer in the rotating frame
Author(s) -
Hwang TsangLin,
Kadkhodaei Mehran,
Mohebbi Afsaneh,
Shaka A. J.
Publication year - 1992
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1260301308
Subject(s) - chemistry , spins , magnetization transfer , magnetization , pulse sequence , scalar (mathematics) , polarization (electrochemistry) , relaxation (psychology) , j coupling , coupling (piping) , statistical physics , nuclear magnetic resonance spectroscopy , nuclear magnetic resonance , condensed matter physics , physics , quantum mechanics , magnetic field , geometry , medicine , psychology , social psychology , mechanical engineering , mathematics , organic chemistry , magnetic resonance imaging , engineering , radiology
Two‐dimensional (2D) NMR spectroscopy has become a routine part of molecular structure determination in liquids. In most modern experiments there is some correlation of transition frequencies between the two dimensions, and the mechanism responsible for the correlation dictates the information obtainable from the 2D spectrum. Two distinct mechanisms for magnetization transfer are considered: scalar coupling and cross‐relaxation. The former gives rise to information about the proximity of spins through the electronic framework of the molecule and the latter provides information on spatial proximity and molecular motion. Two‐dimensional experiments of both types are described, concentrating in particular on TOCSY and ROESY. It is shown how polarization transfer can be tailored and controlled, and how the unwanted coherent transfer due to J coupling can be eliminated in the ROESY experiment. Throughout the discussion, the multiple‐pulse sequence used for each experiment is the central focal point, and its design and analysis are the main considerations.