Detection of intermolecular chemical exchange through decorrelation of two-spin order

An initial correlation between two spins is lost when they are separated by intermolecular chemical exchange. This effect, termed "decorrelation by chemical exchange," manifests itself in a decay of the corresponding two-spin modes. It can be used for monitoring intermolecular chemical exchange, as is demonstrated for l-tryptophan where the decay of 1H15N two-spin order provides information on the exchange of indole protons with solvent water.