Abstract:
The synthesis and characterisation of a large family of trimetallic
[Mn-3(III)] Single-Molecule Magnets is presented. The complexes
reported can be divided into three categories with general formulae
(type 1) [(Mn3O)-O-III(R-sao)(3)(X)(sol)(3-4)] (where R = H, Me, Bu-t;
X = -O2CR (R = H, Me, Ph etc); sol = py and/or H2O), (type 2)
[(Mn3O)-O-III(R-sao)(3)(X)(sol)(3-5)] (where R = Me, Et, Ph, Bu-t; X =
-O2CR (R = H, Me, Ph etc); sol = MeOH, EtOH and/or H2O), and (type 3)
[(Mn3O)-O-III(R-sao)(3)(sol)(3)(XO4)] (where R = H, Et, Ph, naphth;
sol = py, MeOH, beta-pic, Et-py, Bu-t-py; X = Cl, Re). We show that
deliberate structural distortions of the molecule can be used to tune
the observed magnetic properties. In the crystals the ferromagnetic
triangles are involved in extensive inter-molecular H-bonding which is
clearly manifested in the magnetic behaviour, producing exchange-biased
SMMs. These interactions can be removed by ligand replacement to give
“simpler” SMMs.
