Reto Basler, Andreas Sieber, Grégory Chaboussant, Hans U. Güdel, Nicole E. Chakov, Monica Soler,
George Christou, Arnaud Desmedt and Ruep Lechner

**Inelastic Neutron Scattering Study of Electron Reduction in Mn**_{12} Derivatives

*Inorg. Chem.* __44__, 649-453 (2005)

**Abstract:**
We report inelastic neutron scattering (INS) studies on a series of
Mn_{12} derivatives,
[Mn_{12}O_{12}(O_{2}CC_{6}F_{5})_{16}(H_{2}O)_{4}]^{z},
in which the number of unpaired electrons in the cluster is varied. We
investigated three oxidation levels: *z* = 0 for the neutral complex,
*z* = -1 for the one-electron reduced species and *z* = -2 for the
two-electron reduced complex. For *z* = 0, the ground state is *S* =
10 as in the prototypical Mn_{12}-acetate. For *z* = -1, we have
*S* = ^{19}/_{2}, and for *z* = - 2, an *S* = 10
ground state is retrieved. INS studies show that the axial zero-field splitting
parameter *D* is strongly suppressed upon successive electron reduction:
*D* = -0.45 cm^{–1} (*z* = 0), *D* = -0.35
cm^{–1} (*z* = -1), and *D*
-0.26 cm^{–1} (*z* =
-2). Each electron reduction step is directly correlated to the conversion of
one anisotropic (Jahn-Teller distorted) Mn^{3+} (*S* = 2) to one
nearly isotropic Mn^{2+} (*S* = ^{5}/_{2}).