Single-molecule magnets. A Mn12 complex with mixed carboxylate-sulfonate ligation: [Mn12O12(O2CMe)8(O3SPh)8(H2O)4]

MeOH-coordinated Mn12 single-molecule magnet: structure and magnetic properties of [Mn12O12(OAc)16(MeOH)4]

“…Complex 1 also shows the properties of macroscopic quantum tunneling of magnetization with a large ground state spin S (=10), and a negative D (= À0.72 K) [1]. For grasping its chemical characters and properties more thoroughly, many Mn 12 clusters have been prepared by the chemical modification including substitutions of bridging acetates to other carboxylates [4][5][6] or to oxo anions other than carboxylates [7][8][9], and partial substitutions of a peripheral Mn III ion to an Fe III ion [10] or a Cr III ion [11]. Although most of Mn 12 complexes reported so far have four coordinating water molecules, only a few examples [4,[12][13][14][15] are known to have three or two coordinating water molecules, and only one complex does not contain any coordinating water molecules [16].…”

The Quest for Nanoscale Magnets: The example of [Mn12] Single Molecule Magnets

“…However, the steps attributed to quantum tunneling between spin-up and spin-down states in the case of the oriented crystal sample are undetectable in the case of molecules on the surface. While step broadening has been observed in the 3D crystal, due to a change of ligands or solvent used for crystallization, [68] we expect the effect to be more severe in 2D systems where the coherence length of ordered molecule domains is less than 50 nm. The large distribution of molecular environments arising from ligand and orientation disorder may then also lead to inhomogeneous broadening of the steps due to an angular distribution of the magnetization easy axes.…”

“…Periodic defects such as dislocation lines of surface reconstructions and steps of vicinal surfaces can be used to guide the assembly of adsorbed objects such as atoms or molecules. [65][66][67][68][69] In the general case of non-reconstructed surfaces, a random distribution of molecules is observed, as illustrated in the STM image of Figure 3c. As a result, direct deposition of [Mn-Piv] on gold substrates allowed the observation of isolated SMMs by STM.…”

[Mn12O12(O2CMe)12(NO3)4(H2O)4]: facile synthesis of a new type of Mn12complex

“…Many derivatives of the Mn 12 molecule have been synthesized with different bridging groups, including benzoate (Sessoli et al, 1993), and its derivatives (Aubin et al, 1999), tert-butyl acetate (Sun et al, 1998), pivalate, phosphinate (Brockman et al, 2003), sulfonate (Chakov et al, 2003), and dichloroacetate (Eppley & Christou, 2002), to name a few. These molecules all retain similar properties in terms of magnetic character, but crystallize in a wide variety of symmetries and space groups.…”