Reactions of N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine (H4edte) with MnCl2·4H2O or FeCl3·6H2O in MeOH or MeCN with different bases yield four butterfly-like tetranuclear clusters with fused defective dicubane M4O6 cores: [MnII2MnIV2(μ4-Hedte)2(thme)2]·MeCN (1) (H4edte = N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine, H3thme = 1,1,1-tris(hydroxymethyl)ethane), [MnII2MnIV2(μ4-Hedte)2(thme)2]·2MeOH (2), [FeIII4(μ4-Hedte)2(N3)6]·2MeCN (3) and [FeIII4(μ4-edte)2(N3)4(MeOH)2] (4). Both 1 and 3 crystallize in the triclinic space groupP
, while 2 and 4 crystallize in the monoclinic space groupP21/c and P21/n, respectively. The hexadentate Hedte3− ligand in 1–3, and the edte4− ligand in 4 acts in a similar μ4:η1:η1:η1:η2:η2:η3 coordination mode to bridge four metal ions into butterfly-like tetranuclear clusters with fused defective dicubane M4O6 cores. Magnetic studies show that 2 has the spin ground state ST = 8 while 4 has the spin ground state ST = 0. Within the Mn4O6cluster core of 2, both Mn(IV)⋯Mn(II) and Mn(II)⋯Mn(II) ferromagnetic interactions (JMn(IV)⋯Mn(II) = +2.91 cm−1 and JMn(II)⋯Mn(II) = +7.94 cm−1) occur contrary to the Fe4O6 core, where antiferromagnetic exchange exists (Japtical-Fe(III)⋯central-Fe(III) = −15.4 cm−1 and Jcentral-Fe(III)⋯central-Fe(III) = −4.5 cm−1).