New tetranuclear manganese clusters with [Mn II3MnIII] and [Mn II2Mn III2] metallic cores exhibiting low and high spin ground state†
Two tetranuclear mixed-valent clusters, [MnII3MnIIICl(Ph3CCOO)4(CH3OCH2CH2O)4(CH3CN)]·0.4C6H5CH3·0.6CH3CN (1) with an unprecedented [MnII3MnIII] core and [MnII2MnIII2Cl4(CH3OCH2CH2O)6] (2), were synthesized and characterized by single-crystal X-ray diffraction and magnetic measurements. Their properties were analyzed in the framework of phenomenological modelling and DFT calculations, showing acceptable agreement between theory and experiment. Both building blocks [MnII3MnIII] and [MnII2MnIII2] provide good examples of bipartite systems with the lowest ST = 1/2 and highest ST = 9 magnetic ground states available for them. The topology of the magnetic interactions in the [MnII3MnIII] core provides a suitable template for the molecular qubit implementation and the stability of the spin-1/2 ground state strongly depends on the antiferromagnetic MnII–MnII coupling.