Homonuclear single transition correlation spectroscopy of rare spins

An alternative approach for rare spin homonuclear correlation spectroscopy is proposed and examined, which does not involve double quantum evolution. It relies instead on double quantum filtration resulting in a set of single transitions. This is followed by evolution and zero quantum mixing, generating a diagonal suppressed, single transition correlation spectrum that attains an efficiency matching the bound on unitary coherence transfer, but in fact benefits from reduced relaxation losses. This generally results in modest signal intensity improvement in a given measurement time, compared to the most efficient INADEQUATE variant. Results on 13C are reported and confirm the expected behavior.