A single molecule magnet to single molecule magnet transformation via a solvothermal process: Fe4Dy2 → Fe6Dy3

Two series of heterometallic Fe-III-Ln(III) compounds, [Fe(4)(III)Ln(2)(III)(mu(3)-OH)(2)(mdea)(4)(m-NO2C6H4COO)(8)]center dot 3MeCN where Ln = Y (1) and Dy (2) and [Fe(6)(III)Ln(3)(III)(mu(4)-O)(3)(mu(3)-O)(mdea)(5)(m-NO2C6H4COO)(9)]center dot 3MeCN where Ln = Y (3) and Dy (4), were synthesized. Compounds 1 and 2 were obtained under ambient conditions, whereas 3 and 4 were obtained via a solvothermal transformation process by heating 1 or 2 at 120 degrees C in MeCN. The magnetic properties of all four compounds have been measured and show that compounds 2 and 4 containing DyIII ions exhibit slow relaxation of magnetization characteristic of Single Molecule Magnetic (SMM) behaviour.