Solvent Responsive Magnetic Dynamics of a Dinuclear Dysprosium Single‐Molecule Magnet

A new dysprosium(III) phosphonate dimer {Dy(notpH4)(NO3)(H2O)}2·8H2O (1) [notpH6=1,4,7-triazacyclononane-1,4,7-triyl-tris(methylenephosphonic acid)] that contains two equivalent Dy(III) ions with a three-capped trigonal prism environment is reported. Complex 1 can be transformed into {Dy(notpH4)(NO3)(H2O)}2 (2) in a reversible manner by desorption and absorption of solvent water at ambient temperature. This process is accompanied by a large dielectric response. Magnetic studies reveal that both 1 and 2 show thermally activated magnetization relaxation as expected for single-molecule magnets. Moreover, the magnetic dynamics of the two compounds can be manipulated by controlling the number of solvent molecules at room temperature.