Heterometallic hexanuclear isobutyrate clusters based on di- and tripodal alcohols

Four hexanuclear coordination clusters containing $\{{\mathrm{M}}_4^{\mathrm{II}}{\mathrm{M}}_2^{\mathrm{III}}\}$ cores of edge-sharing coordination octahedra exemplify how mixed-spin derivatives of a homonuclear parent structure, ${\mathrm{Mn}}_4^{\mathrm{II}}{\mathrm{Mn}}_2^{\mathrm{III}}{\mathrm{L}}_8$(N–O)₄], can be realized by a ligand ‘shrink-wrapping’ approach, resulting in ${\mathrm{Mn}}_2^{\mathrm{II}}{\mathrm{Co}}_2^{\mathrm{II}}{\mathrm{Mn}}_2^{\mathrm{III}}{\mathrm{L}}_8$(N–O)₄]- and ${\mathrm{Co}}_4^{\mathrm{II}}{\mathrm{Fe}}_2^{\mathrm{III}}{\mathrm{L}}_8$(N-O)₄]-type clusters (L = isobutyrate, N–O = methyldiethanolamine, n-butyldiethanolamine, or triethanolamine). The resulting core structures are either virtually isostructural to the parent structure or differ in the placement of the peripheral metal ions, depending on the mix of structure-directing carboxylate and alkoxyamine ligands with large, flexible alkyl chains. Whereas the $\{{\mathrm{Mn}}_4^{\mathrm{II}}{\mathrm{Mn}}_2^{\mathrm{III}}\}$ and {${\mathrm{Co}}_4^{\mathrm{II}}{\mathrm{Fe}}_2^{\mathrm{III}}$} complexes show dominant antiferromagnetic exchange, ferrimagnetic coupling features are exhibited by two {${\mathrm{Mn}}_2^{\mathrm{II}}{\mathrm{Co}}_2^{\mathrm{II}}{\mathrm{Mn}}_2^{\mathrm{III}}$} clusters.