The mixed valence dodecanuclear complex [Mn12O12(O2CEt)16(H2O)3] may be reduced by one electron to give (PPh4) [Mn12O12(O2CEt)16(H2O)4]. Reduction of the complex occurs at one MnIII ion to give an unusual trapped-valence MnIIMnIII7Mn'V4 complex. This formulation is supported by X-ray crystallography at both low temperature and room temperature. DC (2.0-4.0K, 2050 kG fields) and AC (2.0-30 K, 1.0 and 0.0050G fields, 25-1000 Hz frequencies) magnetic susceptibility measurements indicate ground states of S=9 and S=19/2 for the neutral and reduced species, respectively. (PPh4)| Mn12 2012(O2CEt)] 16(H2O)4] exhibits an out-of-phase component of the AC magnetic susceptibility (Xm) which has a frequency dependent maximum. This is a very unusual property for a discrete molecular species to display. The neutral analog shows two peaks in the Xm vs- T plot. DC measurements also show the presence of prominent hysteresis loops, and field-cooled and zero-field-cooled magnetization data are not superimposed at low temperatures. The unusual magnetic relaxation properties persist even in polystyrene-doped samples of the complexes, indicating that this behavior arises from intramolecular rather than intermolecular properties.
|Number of pages||7|
|Journal||Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals|
|Publication status||Published - 1995 Nov|
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics