| 637041-60-2

• CAS: 637041-60-2
• 化学式: C₅₂H₆₈Cl₄Mn₄N₄O₈
• 分子量: 1238.7
• InChiKey: KHSXAFZDYUOSJV-AIPZYIEWSA-F

反应信息

• 作为产物：
  描述：

  manganese(II) chloride tetrahydrate 、 4-tert-butyl-salicylidene-2-ethanolamine 在 air 作用下， 以 乙醇 为溶剂， 以12%的产率得到
  参考文献：
  名称：

  Ferromagnetic and Antiferromagnetic Intermolecular Interactions in a New Family of Mn₄ Complexes with an Energy Barrier to Magnetization Reversal

  摘要：

  A new family of tetranuclear Mn complexes [Mn4X4L4] (H2L = salicylidene-2-ethanolamine; X = Cl (1) or Br (2)) and [Mn4Cl4(L')4] (H2L' = 4-tert-butyl-salicylidene-2-ethanolamine, (3)) has been synthesized and studied. Complexes 1-3 possess a square-shaped core with ferromagnetic exchange interactions between the tour Mn-III centers resulting in an S = 8 spin ground state. Magnetochemical studies and high-frequency EPR spectroscopy reveal an axial magnetoanisotropy with D values in the range -0.10 to -0.20 cm(-1) for complexes 2 and 3 and for differently solvated forms of 1. As a result, these species possess an anisotropy-induced energy barrier to magnetization reversal and display slow relaxation of the magnetization, which is observed as hysteresis for 1 and 3 and frequency-dependent peaks in out-of-phase AC susceptibility measurements for 3. The effective energy barrier was determined to be 7.7 and 7.9 K for 1 and 3, respectively, and evidence for quantum tunneling of the magnetization was observed. Detailed magneto-chemical studies, including measurements at ultralow temperatures, have revealed that complexes 1 and 2 possess solvation-dependent antiferromagnetic intermolecular interactions. Complex 3 displays ferromagnetic intermolecular interactions and approaches a ferromagnetic phase transition with a critical temperature of similar to1 K, which is coincident with the onset of slow relaxation of the magnetization due to the molecular anisotropy barrier to magnetization reversal. It was found that the intermolecular interactions have a significant effect on the manifestation of slow relaxation of the magnetization, and thereby, these complexes represent a new family of "exchange-biased single-molecule magnets", where the exchange bias is controlled by chemical and structural modifications.

  DOI：

  10.1021/ja0367086