The electronic structures of the compounds K[(5-Brsalen)₂(H ₂O)₂-Mn₂M^III(CN)₆] · 2H₂O (M^III = Co^III, Cr^III, Fe^III) have been determined by inelastic neutron scattering (INS) and magnetic susceptibility studies, revealing the manganese(lll) single-ion anisotropy and exchange interactions that define the low-lying states of the Mn-M^III-Mn trimeric units. Despite the presence of an antiferromagnetic intertrimer interaction, the experimental evidence supports the classification of both the Cr(lll) and Fe(lll) compounds as single-molecule magnets. The value of 17(2) cm^-1 established from AC susceptibility measurements for a spin-reversal barrier of K[(5-Brsalen)₂(H ₂0)₂-Mn₂Cr(CN)₆] · 2H ₂0 may be readily rationalized in terms of the energy level diagram determined directly by INS. AC susceptibility measurements on samples of K[(5-Brsalen)₂(H₂0)₂-Mn₂Fe(CN) ₆] · 2H₂O are contrary to those previously reported, exhibiting but the onset of peaks below temperatures of 1.8 K at oscillating frequencies in the range of 100-800 Hz. INS measurements reveal an anisotropic ferromagnetic manganese(III)-iron(lll) exchange interaction, in accordance with theoretical expectations based on the unquenched orbital angular momentum of the [Fe(CN)₆]^3- anion, giving rise to an M_s ∼ ±9/2 ground state, isolated by ∼11.5 cm ^-1 from the higher-lying levels. The reported INS and magnetic data should now serve as a benchmark against which theoretical models that aim to inter-relate the electronic and molecular structure of molecular magnets should be tested.