Further perspective on the theory of heteronuclear decoupling

The dynamic that refocuses (decouples) magnetization Sx in heteronuclear spin-12 IS systems is the change in sign of antiphase magnetization 2SyIz. The exact one-to-one correspondence of decreasing Sx for 2SyIz>0 (blue line) and increasing Sx (refocusing) for 2SyIz<0 (green line) is illustrated for a novel aperiodic decoupling sequence that accesses new degrees of freedom described in the theory to surpass the performance of traditional cyclic sequences. Complete refocusing (Sx=1) in decoupling occurs when ∫2SyIzdt=0. 63