Single-molecule magnets: [Mn12O12(O2CCF2Cl)16(H2O)4]0/−

The syntheses, X-ray crystal structures and magnetic properties of [Mn12O12(O2CCF2Cl)16(H2O)4] (1) and [PPh4][Mn12O12(O2CCF2Cl)16(H2O)4] (2) are reported. Complex 1 · 4H2O crystallizes in the tetragonal space group I4¯ at 150(1) K with a = 18.6838(1) Å, c = 13.3829(5) Å, and Z = 2. Reduction of complex 1 with PPh4I in CH2Cl2 leads to isolation of complex 2 · 2H2O · CH2Cl2, it crystallizes in the monoclinic space group P21/c at 150(1) K with a = 18.6623(7) Å, b = 13.3626(5) Å, c = 45.4482(17) Å, β = 97.204°, and Z = 4. The results of DC and AC magnetic susceptibility studies are described. DC studies of complexes 1 and 2 in a 1.0 kG field show maxima of the χMT versus T plot in the 5–10 K range at 47.63 and 54.27 emu K mol−1, respectively. Complexes 1 and 2 exhibit out-of-phase component of the AC magnetic susceptibility with frequency dependent maxima. Step-like features are seen on hysteresis loops of complex 1. DC decay relaxation of complex 1 shows quantum tunneling behavior below 2.1 K.

The syntheses, X-ray crystal structures and magnetic properties of [Mn12O12(O2CCF2Cl)16(H2O)4] (1) and [PPh4][Mn12O12 (O2CCF2Cl)16(H2O)4] (2) are reported. The results of DC and AC magnetic susceptibility studies are described. Complexes 1 and 2 exhibit two out-of-phase component of the AC magnetic susceptibility with frequency dependent maxima. The anisotropic energies U/kB are 82.7, 64.8, 56.4 and 32.4 K for complexes 1(HT), 2(HT), 1(LT) and 2(LT), respectively. Step-like features are seen on hysteresis loops of complex 1. DC decay relaxation of complex 1 shows quantum tunneling behavior below 2.1 K.Figure optionsDownload as PowerPoint slide