E-BURP-2 excitation in the CPMG sequence for improving reliability of relaxation data in the study of guest/host interactions in inclusion complexes in water

A modification of the classical Carr–Purcell–Meiboom–Gill sequence, in which the first 90° pulse is replaced by a selective E-BURP-2 pulse, is described. It is shown that the absence of dispersion contributions in the frequency response of the selected absorption region is a pre-requisite for obtaining reliable data. The importance of leaving the water magnetization along the longitudinal axis is also pointed out. The potentialities of the method are illustrated in the study of intermolecular interactions in the case of inclusion complexes.