title: Approximate solutions of the Bloch-McConnell equations for two-site chemical exchange.
abstract: Approximate formulas for the transverse-relaxation rate constant and resonance frequency have been derived for nuclear spins subject to two-site chemical exchange. The new results are more accurate than previous approximations when chemical exchange does not approach the fast-exchange limit or when site populations are not highly asymmetric. Results are derived from an effective average evolution operator that contains contributions from both exact eigenvalues of the Bloch-McConnell equations. These expressions are useful for interpretation of chemical exchange processes in NMR spectroscopy.
authors.affiliation: Laboratoire de Chimie, Ecole Normale Supérieure 24, rue Lhomond, 75005 Paris, France. daniel.abergel@ens.fr
authors.forename: Daniel
authors.initials: D
authors.lastname: Abergel
authors.forename: Arthur G
authors.initials: AG
authors.lastname: Palmer
mesh_terms: D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D012996:Solutions / Q000737:chemistry
chemical_list: D012996:Solutions