Probing the magnetic moments of [MnIII6CrIII]3+ single-molecule magnets—A cross comparison of XMCD and spin-resolved electron spectroscopy

Abstract

a b s t r a c t Single-molecule magnets (SMM) of the [Mn III 6 Cr III ] 3+ structural type prepared on Si and gold-coated glass substrates have been investigated by spin-resolved electron spectroscopy (SPES) and X-ray magnetic circular dichroism (XMCD) at the Mn L 3,2 edge and in addition by XMCD at the Cr L 3,2 edge using synchrotron radiation. Differences between the two methods are discussed. Despite its severe limitations for 3d transition metals, a spin sum rule evaluation is nevertheless performed for the Mn III centres in the [Mn III 6 Cr III ] 3+ SMM to provide a simple means of comparing XMCD and spin-resolved electron spectroscopy results.

Optimization of Single‐Molecule Magnets by Suppression of Quantum Tunneling of the Magnetization

“…Indeed, the reaction of two in situ generated trinuclear complexes [(talen t –Bu2 )M t 3 ] n + with a hexacyanometallate [M c (CN) 6 ] n –6 results in heptanuclear complexes [M t 6M c ] n + (= [{(talen t –Bu2 )M t 3 } 2 {M c (CN) 6 }] n + ) . We took advantage of this molecular recognition to build an isostructural series of heptanuclear complexes by varying the central hexacyanometallate and the terminal metal ions, namely [Mn III 6 Cr III ] 3+ ,, [Mn III 6 Mn III ] 3+ ,, [Mn III 6 Fe II ] 2+ , [Mn III 6 Fe III ] 3+ ,, [Mn III 6 Co III ] 3+ , [Mn III 6 Os II ] 2+ , [Mn III 6 Os III ] 3+ , and [Fe III 6 Cr III ] 3+ . Most of these complexes exhibit a slow relaxation of the magnetization.…”