TY - JOUR
T1 - High spin molecules
T2 - Unusual magnetic susceptibility relaxation behavior of a dodecanuclear manganese aggregate in two oxidation states
AU - Ts Ai, Hui Lien
AU - Eppley, Hilary J.
AU - De Vries, Nadine
AU - Folting, Kirsten
AU - Christou, George
AU - Hendrickson, David N.
N1 - Funding Information:
This work is supported by NSF grants CHE-9115286 (D.N.H.) and CHE-8808019 and CHE-93 11904 (G.C.) The AC magnetic susceptibility measurements were performed with an AC SQUID susceptometer provided by the Center for Interface and Material Science, funded by the W. A. Keck Foundation. H.J.E. was supported by an NSF Predoctoral Fellowship.
PY - 1995/11
Y1 - 1995/11
N2 - 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.
AB - 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.
UR - https://www.scopus.com/pages/publications/0029487928
UR - https://www.scopus.com/pages/publications/0029487928#tab=citedBy
U2 - 10.1080/10587259508031877
DO - 10.1080/10587259508031877
M3 - Article
AN - SCOPUS:0029487928
SN - 1058-725X
VL - 274
SP - 167
EP - 173
JO - Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals
JF - Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals
IS - 1
ER -