title: Control of cross relaxation of multiple-quantum coherences induced by fast chemical exchange under heteronuclear double-resonance irradiation.
abstract: A fully analytical description of the control of the cross-correlated cross relaxation of multiple-quantum coherences in the presence of local dynamics under heteronuclear double-resonance radio-frequency (RF) irradiation is presented. The contribution of chemical exchange to relaxation can be partly or fully quenched by RF fields. We assume a correlated two-site chemical exchange model with arbitrary populations, and show that in the limit of fast exchange the dependence of the effective multiple-quantum cross-relaxation rate on the applied RF amplitude can be described by a compact analytical expression. Numerical simulations and preliminary experiments support our theoretical results. The relaxation dispersion as a function of RF amplitude can provide accurate information on the kinetics of correlated processes.
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne, Institut des Sciences et Ingénierie Chimiques, 1015 Lausanne, Switzerland. simone.ulzega@epfl.ch
authors.forename: Simone
authors.initials: S
authors.lastname: Ulzega
authors.forename: Nicola
authors.initials: N
authors.lastname: Salvi
authors.forename: Takuya F
authors.initials: TF
authors.lastname: Segawa
authors.forename: Fabien
authors.initials: F
authors.lastname: Ferrage
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Bodenhausen