Pseudo-Tetrahedral vs Pseudo-Octahedral ErIII Single Molecule Magnets and the 'Disruptive' Role of Coordinated TEMPO Radicals

Erbium(III) complexes are the most interesting candidates for high-performance single molecule magnets (SMMs) just after dysprosium(III). Herein, we thoroughly explore the underrepresented class of neutral pseudo-tetrahedral erbium(III) SMMs and demonstrate their exceptional slow magnetization dynamics controlled by the Raman relaxation mechanism and the molecular magnetic memory effect in the form of a waist-restricted magnetic hysteresis loop. The influence of the coordinated TEMPO radical on the slow magnetization relaxation performance is also demonstrated and discussed.