Yttrium-89 NMR: A Possible Spin Relaxation Probe for Studying Metal Ion Interactions with Organic Ligands

摘要

The spin-lattice relaxation mechanisms for aqueous and dimethyl sulfoxide solutions of Y(NO3)3 have been found to be mainly spin-rotation and dipolar relaxation with solvent protons, unlike most heavy spin=1/2 metal ions which are relaxed mainly by spin-rotation and chemical shift anisotropy. The theoretical maximum (89)Y((1)H) NOEF value of -10.2 was observed when tau (c) for the ion was lengthened by lowering the temperature of the aqueous salt solution to 5C, or when yttrium was complexed to an organic ligand. Since (89)Y has a sensitivity of 0.67 relative to that of (13)C, the relative importance of dipolar relaxation and the large theoretical maximum NOEF make (89)Y a possible value NOE structure probe. Such studies can complement relaxation and shift data obtained from other diamagnetic and paramagnetic lanthanid ions.