Off-resonance effects on coherence transfer in homonuclear spin-lock experiments

Homonuclear spin-lock experiments are characterized under various conditions of "continuous" spin lock, employing commutator algebra, as well as subspace descriptions. General expressions are derived for AXN systems (N: arbitrary) under off resonance conditions; explicit expressions for the observed signal including phase anomaly components are tabulated for AX and AX2 systems. The predictions have been verified by experiments on an AX2 system. Some distinctive features of the dynamics are discussed vis-à-vis the heteronuclear situation. © 1990.