A trinuclear manganese complex, [Mn3O(Me-salox)(3)(2,4'-bpy)(3)-(ClO4)] center dot 0.5MeCN (1.0.5MeCN; Me-H(2)salox = 2-hydroxyphenylethanone oxime), has been synthesized and characterized structurally as a [MnIII3(mu(3)-O)](7+) core. Structural distortion by the twisting of the oxime ligand dominates ferromagnetic interactions within three Mn ions to give an S = 6 ground state as well as to enhance the anisotropy barrier U-eff to 37.5 K.