LINESHAPE AND RELAXATION OF SPINS I=1 2 COUPLED TO S=3 - APPLICATION TO SELECTIVE DETECTION OF PROTONS ATTACHED TO B-10/

The rapid spin-lattice relaxation of quadrupolar nuclei is a dominant mechanism for the transverse relaxation of attached hydrogens. The eff ects of this scalar relaxation were calculated exactly for protons att ached to nuclei with spin S = 3, assuming that the quadrupolar relaxat ion is in the isotropic extreme narrowing limit. The preferred techniq ue for indirect detection of the spin-3 nuclei, via their attached hyd rogens, depends on the ratio between the heteronuclear coupling consta nt and the quadrupolar relaxation rate. The theoretical analysis was f ound to be in good agreement with the results of spin-echo difference experiments conducted on borocaptate monomer (BSH) and dimer (BSSB) an ions in aqueous solution. (C) 1995 Academic Press, Inc.