Fast tunneling Jahn–Teller isomer of the [Mn12O12(O2CC6H4-2-CH3)16(H2O)4] · S single-molecule magnet

The single-crystal X-ray structure of the single-molecule magnet [Mn12O12(O2CC6H4-2-CH3)16(H2O)4] · CH2Cl2 · 2H2O (complex 1) is reported. Complex 1 is a new example of a “Jahn–Teller isomer”, since it has two Mn(III) ions with abnormally oriented Jahn–Teller elongation axes. Complex 1 has a lower activation energy (Ueff = 29 K) for magnetization reversal relative to other reported [Mn12O12] type molecules (e.g., Ueff = 70 K for Mn12Ac). Single-crystal low temperature magnetization measurements are reported that confirm that complex 1 is a single-molecule magnet. High-field electron paramagnetic resonance measurements were performed on a single crystal to give the spin Hamiltonian parameters.

Graphical abstractA single-crystal X-ray structure reveals that the title compound is a new example of a “Jahn-Teller isomer” among Mn12 single-molecule magnets. A relatively small activation energy towards magnetization reversal is observed. High-frequency EPR and magnetization measurements have been collected for a single-crystal of this compound.Figure optionsDownload full-size imageDownload as PowerPoint slide