Syntheses, structures and single-molecule magnetic behaviors of two dicubane Mn4 complexes

The reaction of MnX2 · 4H2O (X = Cl or Br) with 2,6-bis(hydroxymethyl)-4-methylphenol (H3L) and NaOH in methanol solution yielded two tetranuclear manganese complexes, [Mn4(HL)4(MeOH)4Cl2] (1) and [Mn4(HL)4(MeOH)4Br2] (2). Both compounds crystallize in the monoclinic space group C2/c with cell parameters: a = 26.0945(19) Å, b = 11.4999(8) Å, c = 21.2188(16) Å, β = 121.050(1)° and z = 4 for 1 · 2Et2O; a = 25.8145(3) Å, b = 11.6734(2) Å, c = 21.3956(3) Å, β = 120.1277(6)° and z = 4 for 2 · 2Et2O. Both complexes consist of a mixed-valence dicubane structure, which comprises two MnII and two MnIII ions. Magnetic susceptibilities and magnetization of complexes 1 and 2 in the solid state indicate that two clusters have an S = 9 ground state. Frequency-dependent out-of-phase signals of alternating current magnetic susceptibilities were observed in the low temperature range (<3 K) for both complexes indicating a slow magnetic relaxation.

Two tetranuclear manganese complexes, [Mn4(HL)4(MeOH)4X2] (X = Cl, Br; H3L = 2,6-bis(hydroxymethyl)-4-methylphenol), consist of a mixed-valence dicubane structure, which comprises two MnII and two MnIII ions. Magnetic susceptibilities and magnetization of both complexes indicate that two clusters have an S = 9 ground state. The AC frequency-dependent out-of-phase signals susceptibilities were observed in the low temperature range indicating a slow magnetic relaxation.Figure optionsDownload as PowerPoint slide