Variation in the electron count and ground state of [Mn ₁₂ O ₁₂ (O ₂ CR) ₁₆ (H ₂ O) ₄ ](R = Me or Ph) by metal substitution and redox changes: preparation and properties of [Mn ₈ Fe ₄ O ₁₂ (O ₂ CMe) ₁₆ (H ₂ O) ₄ ]·4H ₂ O·2MeCO ₂ H and [NPr n ₄ ][Mn ₁₂ O ₁₂ (O ₂ CPh) ₁₆ (H ₂ O) ₄ ]·H ₂ O

As a means of varying the electron count of complexes [Mn12O12(O2CR)16(H2O)4](1; R = Me or Ph), the aggregates [Mn8Fe4O12(O2CMe)16(H2O)4]2 and [NPrn4][Mn12O12(O2CPh)16(H2O)4]3 have been prepared; magnetochemical measurements confirm that the unusual of properties 1 can be significantly altered by ‘conversion’ to 2 and 3.