Magnetic Resonance of 3He and 129Xe in Aqueous Solutions Containing Paramagnetic Mn2+ and Co2+ Ions. A Comparisonwith Isoelectronic 7Li+ and 133Cs+ Ions

Abstract

Noble Gas / 3 He / 129 Xe / Paramagnetic Ions / Aqueous SolutionsThe chemical shifts and relaxation times T1 and T2 of 3 He and 129 Xe nuclei of noble gas atoms as well as those of 7 Li and 133 Cs nuclei of isoelectronic Li ϩ and Cs ϩ ions have been measured in aqueous solutions, which contain paramagnetic Mn 2ϩ and Co 2ϩ ions. The magnetic relaxation of all studied nuclei in Co 2ϩ solutions proceeds via an electronic spin relaxation of these ions. The relaxation in Mn 2ϩ solutions is determined by the translational diffusion of the solute particles. The closest approach distances for collisions of paramagnetic ions with atoms of noble gases and alkali ions were estimated from relaxation data.