Distance-Dependent Paramagnet-Enhanced Nuclear Spin Relaxation of H₂@C₆₀ Derivatives Covalently Linked to a Nitroxide Radical

Abstract

A series of H₂@C₆₀ derivatives covalently linked to a nitroxide radical has been synthesized. We report distance-dependent nuclear spin relaxivity of H₂ in these derivatives. The results clearly indicate that the relaxivity of H₂ is distance-dependent and in good agreement with the Solomon−Bloembergen equation, which predicts a 1/<i>r</i>⁶ dependence