Accelerated spin dynamics in NMR driven by homonuclear scalar couplings

The influence of homonuclear scalar couplings on multiple quantum coherences evolving under isotropic mixing is investigated. In suitable clusters of four or more spins-1/2 (or two or more spins >1/2), zero and multiple quantum coherences are shown to evolve at high frequencies that involve multiples of the coupling constant. This behavior under spin lock is consequent on the cluster being in a superposition of spin coupling eigenstates that differ in composite spin by more than one unit. The resulting accelerated spin dynamics also offers opportunity to measure unresolved couplings in MRS and in high resolution NMR.